Dissertations / Theses on the topic 'Traffic and highway engineering'
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Seshadri, Srikanth R. "Traffic noise analysis at highway underpasses." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176399213.
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Yu, Tungsheng. "Traffic flow modeling in highway networks." Master's thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-12232009-020154/.
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Ljumanovic, Lea. "Low cost passive dampers for highway traffic signs." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/702.
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A low cost passive mass-rubber damper is introduced in this work to mitigate damage of highway signs caused by ground motion and wind gusting. The damper is designed and constructed to alleviate stresses due to bending, shear, and fatigue loading. Lab experiments based on sign responses and strains were conducted in order to evaluate the damper effectiveness in extending the life of the sign structure. Experimental Modal Analysis was performed to deduce the modal parameters of the structure using Easy Analyst and ME'scope commercial software. Ground motion was simulated using a shaker table and lighten earthquake signals. The wind gusting is simulated by simply pulling the tip of the sign and then releasing it. The results have shown that the proposed damper was able to minimize the horizontal relative ground motion between the base of the structure and the ground, which is an indication of smaller shear forces. Strain results have shown that the proposed damper was able to lower the maximum strain by up 73 percent. Finally, the damper was very effective in filtering the high frequency components of the signals entering the system, minimizing by that failure due to high cycle fatigue.
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Clum, Craig M. "Highway traffic noise barrier overlap gap model." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177442958.
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Allström, Andreas. "Highway Traffic State Estimation and Short-term Prediction." Licentiate thesis, Linköpings universitet, Kommunikations- och transportsystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-128617.
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Traffic congestion is increasing in almost all large cities, leading to a number of negative effects such as pollution and delays. However, building new roads is not a feasible solution. Instead, the use of the existing road network has to be optimized, together with a shift towards more sustainable transport modes. In order to achieve this there are several challenges that needs to be addressed. One challenge is the ability to provide accurate information about the current and future traffic state. This information is an essential input to the traffic management center and can be used to influence the choices made by the travelers. Accurate information about the traffic state on highways, where the potential to manage and control the traffic in general is very high, would be of great significance for the traffic managers. It would help the traffic managers to take action before the system reaches congestion and limit the effects of it. At the same time, the collection of traffic data is slowly shifting from fixed sensors to more probe based data collection. This requires an adaptation and further development of the traditional traffic models in order for them to handle and take advantage of the characteristics of all types of data, not just data from the traditionally used fixed sensors. The objective of this thesis is to contribute to the development and implementation of a model for estimation and prediction of the current and future traffic state and to facilitate an adaptation of the model to the conditions of the highway in Stockholm. The model used is a version of the Cell Transmission Model (CTM-v) where the velocity is used as the state variable. Thus, together with an Ensemble Kalman Filter (EnKF) it can be used to fuse different types of point speed measurements. The model is developed to run in real-time for a large network. Furthermore, a two-stage process used to calibrate the model is implemented. The results from the calibration and validation show that once the model is calibrated, the estimated travel times corresponds well with the ground truth travel times collected from Bluetooth sensors. In order to produce accurate short-term predictions for various networks and conditions it is vital to combine different methods. We have implemented and evaluated a hybrid prediction approach that assimilates parametric and non-parametric short-term traffic state prediction. To predict mainline sensor data we use a neural network, while the CTM-v is ran forward in time in order to predict future traffic states. The results show that both the hybrid approach and the CTM-v prediction without the additional predicted mainline sensor data is superior to a naïve prediction method for longer prediction horizons.
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Sheu, Hsin-Teng. "A coordinated decentralized flow and routing control algorithm for an automated highway system /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu148758564557836.
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Leotsarakos, Christos. "A comparative statistical analysis of traffic accidents in highway construction zones." Connect to resource, 1988. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1260541199.
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Phan, Thao Kim. "A model-based dynamic toll pricing strategy for controlling highway traffic." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101488.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 40-42).
A model-based approach to dynamic toll pricing has been developed to provide a systematic method for determining optimal freeway pricing schemes. A novel approach is suggested for alleviating traffic congestion, which utilizes identified models of driver behavior and traffic flow, as well as optimization of the target density to maximize throughput. Real-time traffic information from on-road sensors is integrated with historical information to provide feedback and preview for the dynamic toll price controller. The algorithm developed here provides an opportunity to improve on existing toll policy by guaranteeing minimum speeds for toll lane drivers, maintaining consistent traffic flow for the other drivers, and optimizing the overall traffic throughput.
by Thao Kim Phan.
S.M.
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Sim, Samuel Wook. "An initial investigation for a monitoring program for the safety performance of design exceptions in Georgia." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45815.
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In roadway projects, design exceptions are implemented when the project site consists of one or more substandard design elements. The objective of this thesis is to conduct an initial investigation for a monitoring program for the safety performance of design exceptions in Georgia. A total of 467 projects containing design exceptions were reported in Georgia from 1995 to 2011, and from this crash data for 179 projects from 2003 to 2008 were sampled. The crash data collected in this research pertains to all roadway segments within the projects and is not necessarily related to the design exceptions. Future efforts will be required to explore potential connections between the crash rates and design exceptions.
The annual crash results generally revealed a high variability and randomness in the data. For this reason, the average 3-year crash frequencies before design exception approval date and after it were calculated to determine the safety performance for projects containing design exceptions. A method for determining expected results using the Highway Safety Manual (HSM) predictive method is also discussed. The findings will be used to guide future research on design exceptions and mitigation measures to improve roadway safety.
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Fu, Ting. "Effects of adverse winter weather conditions on highway traffic and driver behavior." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123259.
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This research looks into the impact of adverse winter weather conditions on highway driver behaviors using microscopic data from loop detectors and video cameras (e.g., hourly average speed, trajectories, lane changes, time-to-collisions measures). This thesis is composed of two main sections in addition to the introductory section: i) direct and lagged effects of adverse weather on hourly speeds and volumes; and ii) direct effect of adverse weather on driver behaviors (microscopic) measured at the vehicle level using video data. The first part of the thesis presents a review of literature related to past research on the topic. The second part investigates the direct and lagged effects of adverse winter weather conditions on the operating speed in a number of highway segments in Ontario using a time-series approach. This is complemented by the analysis of hourly traffic volumes in the region of Montreal, Canada, using data from magnetic loop detectors as well. In speed modeling, the effect of adverse weather was studied using data from multiple sites including both urban and rural highways, considering weekdays versus weekends separately. For this purpose, a large dataset containing hourly traffic data, weather variables (e.g., temperature, snow, wind speed), and surface conditions was used. A few previous studies have examined the effect of snowstorms on traffic parameters; however, little research has been done regarding the spillover effects (lagged effects) that adverse weather conditions may have on travel demand and traffic patterns. Extreme events or weather conditions might have a strong effect on traffic conditions not only during the events, but also before and after the events. In this study, time-series regression techniques―in particular, Autoregressive Integrated Moving Average (ARIMA) models―were used to model the highway operating speed. These methods are able to consider the serial correlation among error terms. The results indicate that snowstorms have a statistically significant effect on the speed. The lagged effects are however offset by the time and intensity of winter maintenance operations during and after the event. The effect of weather also varies depending on the type of site (urban or rural) and day of the week. Similarly, the effects of different weather variables including their lagged effects were analyzed using hourly traffic volume data. Despite the fact that information of the road surface condition was not available, this analysis is in accordance with previous finding, showing the utility of ARIMA approaches in modeling the highway volume as well. The results of this study can be applied in quantifying the mobility effect of winter weather and benefits of winter road maintenance. In recent years, driver behavior analysis using microscopic (vehicle level) data is a topic that is attracting more attention in road safety analysis. This popularity has brought about research in many different innovative techniques and microscopic measures used to quantify and analyze driver behavior. In the second part of this thesis, it demonstrates a method of analyzing driver behavior using video data approach. This thesis elucidates both a manual and an automated, computer-based method to analyze driver behavior. It also uses the computer-based method to evaluate the effect of adverse winter weather conditions on the driver behavior of highway users. Both the manual and the automated approaches have been used with 15 video recordings obtained from three different locations on the Don Valley Parkway (DVP) in Toronto, Ontario. The results demonstrate the effectiveness of the automated method in analyzing driver behavior, as well as in evaluating the impact of adverse winter weather conditions on driver behavior.La thèse présente l'impact des conditions météorologiques hivernales défavorables sur les comportements des conducteurs de la route à l'aide de données microscopiques de détecteurs de mouvement et des caméras vidéo (e.g., la vitesse horaire moyenne, les trajectoires, les changements de voie, des mesures de temps à la collision) La thèse est composée de deux sections principaux, en plus de l'introduction: i) les effets directs et décalés des conditions météorologiques défavorables sur la vitesse et le volume horaire; et ii) l'effet direct des conditions météorologiques défavorables sur le comportement microscopique des conducteurs mesurées au niveau du véhicule à l'aide de données vidéo.La première partie de la thèse propose une revue de la littérature sur le sujet. La deuxième partie examine les effets directs et décalés des conditions météorologiques hivernales défavorables sur la vitesse opérationnelle dans un certain nombre de segments de la route en Ontario en utilisant une approche de séries chronologiques. Ceci est complété par l'analyse des volumes de trafic horaires dans la région de Montréal, au Canada, en utilisant également les données de détecteurs de boucles magnétiques. Pour modéliser la vitesse, l'effet des conditions météorologiques défavorables a été étudié en utilisant des données provenant de plusieurs sites, dont deux autoroutes urbaines et rurales. Les jours de semaine et les week-ends ont été considérés séparément. Certaines études antérieures ont examiné l'effet de tempêtes de neige sur les paramètres de trafic, mais peu a été fait en ce qui concerne les effets d'entraînement (effets différés) que les conditions météorologiques défavorables peuvent avoir sur la demande de voyage et sur les modèles de trafic. Dans cette étude, les techniques de régression chronologique - en particulier les modèles autorégressives moyennes mobiles intégré (ARIMA) - ont été utilisées pour modéliser la vitesse opérationnelle de l'autoroute. A partir des résultats, on peut déduire que les tempêtes de neige ont un effet statistiquement significatif sur la vitesse. Les effets décalés sont toutefois compensés par la durée et l'intensité des opérations d'entretien hivernal pendant et après l'événement. L'effet de la météo varie aussi en fonction du type de site (urbain ou rural) et le jour de la semaine. Les résultats de cette étude peuvent être appliqués pour quantifier l'effet de la mobilité des conditions météorologiques et les avantages de l'entretien des routes en hiver. De même, les effets des différentes variables météorologiques, y compris leurs effets décalés ont été analysés à l'aide des données de volume de trafic. Malgré que l'information de l'état de surface de la route n'était pas disponible, cette analyse est conforme aux financements antérieurs, montrant également l'utilité des approches ARIMA sur le volume de la route. Au cours des dernières années, le comportement du conducteur en utilisant des données microscopique (niveau du véhicule) est un sujet qui attire plus d'attention à l'analyse de la sécurité routière. Cette popularité a entraîné des recherches sur de nombreux techniques novatrices et le développement de mesures microscopiques utilisées pour quantifier et analyser le comportement du conducteur. Dans la deuxième partie de cette thèse, une méthode est démontrée pour analyser le comportement du conducteur en utilisant l'approche de données vidéo. Cette thèse présente à la fois une démarche manuel et une méthode informatique automatisée pour analyser le comportement du conducteur. Les méthodes manuel et automatique sont utilisées sur 15 enregistrements vidéo obtenus à trois endroits différents sur le Don Valley Parkway (DVP) à Toronto, en Ontario. Les résultats démontrent l'efficacité de la méthode automatisée pour analyser le comportement du conducteur, ainsi que dans l'évaluation de l'impact des conditions météorologiques hivernales défavorables sur le comportement des conducteurs.
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Freckleton, Derek Rulon. "Traffic Operations Analysis of Merging Strategies for Vehicles in an Automated Electric Transportation System." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1418.
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Automated Electric Transportation (AET) is a concept of an emerging cooperative transportation system that combines recent advances in vehicle automation and electric power transfer. It is a network of vehicles that control themselves as they traverse from an origin to a destination while being electrically powered in motion – all without the use of connected wires.
AET's realization may provide unparalleled returns in the form of dramatic reductions in traffic-related air pollution, our nation’s dependence on foreign oil, traffic congestion, and roadway inefficiency. More importantly, it may also significantly improve transportation safety by dramatically reducing the number of transportation-related deaths and injuries each year as it directly addresses major current issues such as human error and adverse environmental conditions related to vehicle emissions. In this thesis, a logical strategy in transitioning from today’s current transportation system to a future automated and electric transportation system is identified.
However, the chief purpose of this research is to evaluate the operational parameters where AET will be feasible from a transportation operations perspective. This evaluation was accomplished by performing lane capacity analyses for the mainline, as well as focusing on the merging logic employed at freeway interchange locations. In the past, merging operations have been known to degrade traffic flow due to the interruptions that merging vehicles introduce to the system. However, by analyzing gaps in the mainline traffic flow and coordinating vehicle movements through the use of the logic described in this thesis, mainline traffic operations can remain uninterrupted while still allowing acceptable volumes of merging vehicles to enter the freeway. A "release-to-gap" merging algorithm was developed and utilized in order to maximize the automated flow of traffic at or directly downstream of a freeway merge point by maximizing ramp flows without causing delay to mainline vehicles. Through these tasks, it is the hope of this research to aid in identifying the requirements and impending impacts of the implementation of this potentially life-altering technology.
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Brunot, Douglas Clair. "SPECIFICATION RECOMMENDATIONS FOR STRUCTURAL SUPPORTS FOR HIGHWAY SIGNS, LUMINAIRES AND TRAFFIC SIGNALS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1145887924.
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Zhou, Dingshan Sam. "An integrated traffic incident detection model /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992952.
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Mahmood, Shah. "Investigating Interchange Traffic and Commercial Development at Rural Interstate Highway Exits." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1469491271.
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Dawkins, Janine Marie. "Analysis of stop-controlled intersections in the Caribbean : a case study of Kingston, Jamaica." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/21524.
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Somers, Julia Marie. "Macroscopic Coupling Conditions with Partial Blocking for Highway Ramps." Master's thesis, Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/326572.
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MathematicsM.S.
We consider the Lighthill-Whitman-Richards traffic model on a network consisting of a highway with an off ramp, connected by a junction. We compare the known coupling conditions for the evolution of traffic at the junction and suggest a novel improvement to the existing conditions. That is, we resolve the spurious effects that arise in standard models, namely clogging of the main highway and vehicle destination changes. We achieve this by tracking vehicle density buildup in the form of a queue, which is modeled by an ODE. We define the solution to the Riemann problem at the junction using the supply and demand functions. The numerical approximation is carried out using a modified Godunov scheme, adjusted to take into account the effects of an emptying queue. Exact and numerical comparisons of the model with existing models verify that the number of vehicles who wish to exit are preserved and the nonphysical clogging of the main highway does not occur.
Temple University--Theses
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Krechowiecki-Shaw, Christopher Jan. "Evolution and remediation of ground failure risk for temporary roads carrying cyclic heavy haul traffic." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8087/.
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Increasing popularity of offsite modular construction has increased demand for transportation of very large (1000-3000 tonne) indivisible loads. Crossing poor soils presents a serious risk of ground failure, particularly as larger vehicles’ greater influence depths produce a very different soil response to conventional vehicles. Temporary haul roads designed conventionally may be excessively conservative and unaffordable as a temporary asset; cost reduction through observational risk management is sought. This thesis experimentally investigates soft silt and clay soils through cyclic triaxial testing. Particular focus is given to anisotropically normally consolidated silt, carefully manufactured through slurry consolidation to replicate liquefiable fabric. Soil samples are tested under the unusual loading conditions associated with heavy haul roads (slow, large-strain, infrequent). A new design approach for temporary heavy haul roads is demonstrated: cyclic traffic load can be used to improve soil, either by gradually rearranging fabric (medium-strain treatment) or remoulding and consolidating excess pore water pressure (large-strain treatment). Liquefiable silt benefits from both, plastic clay only from the latter. These findings, combined with a robust monitoring regime and management of heavy traffic, could be used to improve soil strength over time during operations. This could realise significant project savings and increase viability of modular construction.
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Phan, Vu Le. "Crash risk models for motorcycle-dominated traffic environment of urban roads in developing countries." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/7121/.
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This research developed a new methodology and new models for assessing the potential of motorcycle crashes and selecting countermeasures to improve motorcyclist safety in a motorcycle-dominated traffic environment of urban roads. The crash risk models were developed based on discrete choice models and traffic conflict techniques. The innovative features of this research are that the non-lane-based movements of motorcycles were captured to evaluate their contributions to crash risk and a new concept - that of the Conflict Modification Factor (CoMF) - was proposed to use as a surrogate measure to assess the relative contribution of risk factors to crashes. In addition, a methodology was also developed to enhance the existing International Road Assessment Programme (iRAP) star rating system for motorcyclists. The developed models were fitted and validated using data collected from urban roads in the city of Danang in Vietnam. The operating speed, speed difference, traffic density, front distance, longitudinal gap, lateral clearance and road surface condition were found to significantly contribute to motorcycle crash risk and several countermeasures have been consequently identified to improve motorcyclist safety including: installing changeable speed limit signs, installing changeable gap warning signs, installing changeable road surface condition warning signs and providing segregated motorcycle lanes.
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Hamilton, Andrew. "Improving traffic movement in an urban environment." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/377283/.
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This research seeks to investigate how additional data sources can be used within traffic control systems to reduce average delay and improve reliability of journey time. Current state of the art urban traffic control systems do not take full advantage of the improved granularity of data available as they use traditional, static detection methods such as inductive loops, infra-red and radar. Therefore further research was required to fully understand what new data sources are available, how they could be used and if there are any potential benefits for traffic control systems. The transport industry is moving into an era of data abundance as more people use smart phones, satellite navigation systems, Wi-Fi and Bluetooth devices. These richer data sources could provide additional information (vehicle location, speed and destination data) but it is currently unknown as to whether they can improve the performance of the road network. Much of the research in this thesis has been published through conference and journal papers. A novel traffic control algorithm called DEMA was developed during this research, which can significantly outperform MOVA (a leading industrial control algorithm) through reducing average delay by up to 34% when additional data sources are incorporated into the decision process. DEMA uses vehicle location, speed and turning intention information to select the most suitable stage for minimising delay. Also a study was conducted to determine if turning intention information could be predicted from outside of a vehicle, which is a previously un-researched area. The results demonstrated that people could correctly predict turning intention with a 70% median success rate when the vehicles were 50 metres from the junction. The outcomes of this research could have a significant impact on the future of urban traffic control systems as new data sources become more readily available in the transport industry.
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Cottman, Nicholas James. "Modelling the impacts of intelligent transport systems using microscopic traffic simulation /." [St. Lucia. Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17339.pdf.
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Osra, Khalid A. "Traffic characteristics on the Jeddah-Makkah freeway, Saudi Arabia." Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1174931451.
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Chen, Lei. "Real time traffic management in junction areas and bottleneck sections on mainline railways." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3650/.
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The author of this thesis deals with the issues of real time traffic management in junction areas and bottleneck sections on mainline railways in the event of service disturbances. A systematic methodology is proposed for modelling and solving real time train rescheduling problems in junction areas and bottleneck sections, including train re-sequencing and train re-timing. A formal mathematical model, the Junction Rescheduling Model (JRM) is proposed, based on a Mixed Integer Programming (MIP) to minimise a Weighted Average Delay (WAD). An innovative algorithm based on Differential Evolution algorithm, named DE_JRM is proposed for solving real time train rescheduling problems formulated with JRM. The performance of the algorithm DE_JRM has been evaluated with a stochastic method based on Monte-Carlo simulation methodology. The evaluation results show a good performance for both flyover and flat junctions compared with First Come First Served (FCFS) and a conventional ARS strategy. The author also extends the proposed methodology, including JRM and the algorithm DE_JRM, to model and solve real time train rescheduling problems for bottleneck sections of railway networks. Finally, an integrated system architecture for the traffic management and train control is introduced for system implementation of the proposed methodology of train rescheduling in junction areas and bottleneck sections on mainline railways.
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Stahley, Laura Margot. "Design exception in-service monitoring program development." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50399.
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When project sites consist of substandard design elements according to standards set by the Federal Highway Administration (FHWA), design exceptions are implemented. The goal of this thesis is to analyze a sample set of 18 design exceptions taken from a total of 467 design exceptions approved in Georgia from 1995 – 2012. Crash data were obtained at the locations of each of these design exceptions three years before the let date and three years after the construction end date.
To compensate for causal factors other than the design exception on the roadway, similar information from a range of control sites were also obtained. These control sites consisted of projects without design exceptions that occurred within the same time constraints as the design exception projects, were of the same work type, and were either located on the same route or within the same district. The potential safety impacts of the design exceptions were evaluated by comparing the before and after crash rates of projects before and after crash rates at these control sites
Based on these data, no statistically significant relationship between the existence of a design exception and crash rates was identified. The sample set in this study was too small and the number of crashes found at both projects with design exceptions and control sites without design exceptions was too low to perform a significant Empirical Bayesian (EB) analysis. When additional data is available, an EB before and after analysis is recommended to compensate for any potential regression to the mean bias.
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Yoo, Kyong-Soo. "An empirical analysis of the behavior of weaving traffic in a freeway weaving section." Connect to resource, 1987. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1265732691.
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Polyviou, Polyvios. "Modelling traffic incidents to support dynamic bus fleet management for sustainable transport." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/195335/.
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The continuous implementation of highly technological functions and specifically intelligent transport systems in public transport highlights the need of highly efficient, accurate and reliable bus operations network. Intelligent transport systems can support a variety of functions, including dynamic bus fleet management which has yet to be established in most bus fleets in the UK in a systematic way. In order to support dynamic bus fleet management by detecting the fundamental role of bus and traffic incidents in bus-based public transport, a microscopic simulation model capable of modelling the impact of the individual incidents‟ characteristics on bus operations has been developed and applied to a variety of scenarios. This research draws on a review of existing literature on bus fleet management and available computer software in this field. It investigates research gaps in modelling the impact of traffic incidents on overall bus performance; it describes the design and development of the new simulation model, SIBUFEM (Simulating Incidents for Bus Fleet Management) for modelling bus operations during whole day periods in which incidents of different types can occur. The model simulates a high frequency bus service using existing field data and incorporates the continuous circulation of buses along the bus route. It uses journey time profiles, passenger-dependent bus stop dwell times and deterministic time-dependent queuing theory to model traffic incidents and the impact of their characteristics on the bus performance parameters. The model results, presented in this thesis, focus on performance measures including but not limited to bus journey times, passenger waiting times and bus delays resulting from various bus and traffic incidents. Incidents vary from bus breakdowns, to traffic incidents such as road-works, traffic accidents, burst water mains, disabled vehicles and illegal parking; in SIBUFEM they are specified in terms of their location, duration and severity (i.e. loss of capacity). The model has been applied to a main bus corridor in Southampton, UK, with a base case of „normal‟ operations established, for comparison with results from 24 different incident scenarios, and using key model performance parameters of average bus journey time, bus speed and excess waiting time. This PhD demonstrates the functionality of SIBUFEM with model results demonstrating the extent to which passenger waiting times increase with increasing incident severity and duration. The overall comparison of the simulation results showed that the more severe the level of severity or the longer the duration of an incident, the higher the expected impact of the event on the overall bus performance was. In terms of the incident location parameter, the effect is greater when the incident occurs in the middle of the bus route than when it occurs at the end. The effect of incident location is especially evident in the case of traffic incidents such as roadworks, traffic accidents and illegal parking. Findings from this research also demonstrated that these incidents are usually more severely affected by a change in an incident parameter than by bus breakdown incidents. The thesis concludes with a discussion on potential dynamic bus fleet management strategies and how SIBUFEM can be further developed to allow these strategies to be evaluated. SIBUFEM is capable of modelling traffic incidents to support dynamic bus fleet management and, thus, encourage the use of intelligent transport systems applications in bus operations. This offers great potential in the field of bus-based public transport as part of a guidance tool for bus operators, as well as the way to increase bus level service thereby increasing customer satisfaction and thus the development of a sustainable transport system.
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Ackerman, Kathryn R. "A Critical Review of the Procedure to Develop the State Highway Safety Plan." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1613961199444157.
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Chuo, Kaitlin. "Evaluation of the Applicability of the Interactive Highway Safety Design Model to Safety Audit of Two-Lane Rural Highways." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2299.pdf.
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Adams, David Lewis. "Integrating travel time reliability into management of highways." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 52 p, 2008. http://proquest.umi.com/pqdweb?did=1459913561&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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St-Aubin, Paul. "Traffic safety analysis for urban highway ramps and lane- change bans using accident data and video-based surrogate safety measures." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107783.
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The purpose of this study was to evaluate the traffic safety of urban highway segments near exit and entrance ramps in the Montréal metropolitan area. The city's tight urban environment has resulted in the construction of sub-standard highway ramp merging sections (e.g. short merging lengths, inadequate visibility, influence zone overlap, etc.). In order to mitigate safety problems associated with these inadequately designed features, a special lane-change ban treatment (technical designation LCGV1) was implemented several years ago at various ramps. This study used accident data and video-based surrogate safety measures to evaluate the safety effectiveness of the treatment.The cross-sectional accident analysis controlled for factors such as lane configuration, merge length, traffic flow and speed, area of influence overlap (inter-ramp distance), lane and shoulder widths, horizontal and vertical curves, and covered the presence of the treatment across 10 years of accident data at multiple sites along Montréal's busiest highways. The time-to-collision conflict measure obtained from automated video-based vehicle trajectory extrapolation was analyzed and used to identify microscopic behaviour patterns and conflicting interactions.The study generally concludes that, across all sites, the presence of the treatment has led to no appreciable change in accident rate and that other contributing factors have played a greater role in observed accident rate, time-to-collision distribution, and lane changes. However, the study also indicates that there was significant variation between contributing factors across all analysis sites, leading to the conclusion that adopting a general policy of treating an entire urban region is a futile exercise. In addition, it was observed that the treatment has had a slight accident migration effect. These conclusions lead to the recommendation that the treatment should be applied on a case-by-case basis only, and otherwise that the default case (no treatment) should remain in effect so as not to hinder the normal navigation and operation of highway drivers.Le but de cette étude était d'évaluer la sécurité routière à la hauteur des entrées et des sorties des autoroutes urbaines dans la région métropolitaine de Montréal. Certains sites de cette région comportent des problèmes de conception au niveau de la sécurité routière (notamment une longueur de diffusion trop courte, une visibilité d'approche insuffisante, des zones d'influences se chevauchant, etc.). Afin d'atténuer les problèmes de sécurité associés à ces caractéristiques, un traitement spécial interdisant les changements de voie (désignation technique LCGV1) a été mis en place à ces bretelles. Cette étude vise à évaluer l'efficacité du traitement à partir des données d'accidents et d'une analyse du comportement des usagers à partir des trajectoires des véhicules telles que recueillies depuis des données vidéo. Les facteurs de contrôle de l'analyse transversale comprennent la configuration des voies, la longueur de diffusion, le débit et la vitesse, le chevauchement des zones d'influences (distance des échangeurs), la largeur des voies et des accotements, les courbures horizontales et verticales, et la présence du traitement. L'analyse se fait avec dix ans de données d'accidents à plusieurs sites le long des autoroutes les plus fréquentées de Montréal. L'analyse du comportement des usagers étudie le time-to-collision (TTC) entre les trajectoires des usagers extrapolés depuis des données vidéo et elle identifie les interactions de conflit microscopiques. L'étude conclut généralement que, pour tous les sites, la présence du traitement a conduit à aucun changement appréciable des taux d'accident et que d'autres facteurs ont un effet plus important sur le taux d'accident observé, la distribution du time-to-collision, et les changements de voie. Cependent, on a constaté qu'il y avait des variations importantes de facteurs de site en site, menant à la conclusion que l'adoption d'une politique générale de traitement n'est pas justifiée. En outre, on a remarqué que le traitement avait un léger effet de migration d'accidents. Ces conclusions ont conduit à la recommandation que le traitement soit appliqué au cas par cas seulement.
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Ejzenberg, Sergio. "Os veículos pesados e a segurança no projeto das curvas horizontais de rodovias e vias de trânsito rápido." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-09092009-132108/.
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As curvas horizontais das rodovias notoriamente colecionam acidentes de trânsito, nos quais geralmente os automóveis derrapam e escapam pela tangente, enquanto que os veículos pesados costumam tombar lateralmente. Os critérios consagrados de projeto geométrico das curvas, consideradas planas, ignoram a propensão dos veículos pesados ao tombamento lateral, confiando apenas nas forças de atrito lateral e na superelevação transversal da via para a manutenção do veículo em trajetória segura. O presente trabalho pretende desenvolver modelo de projeto que forneça margens de segurança tanto contra o escorregamento e o tombamento lateral de veículos pesados (semi-reboques) em curvas horizontais com greide descendente. O modelo proposto no presente estudo é sensível a fatores de segurança intrínsecos e extrínsecos aos veículos, incluindo características geométricas longitudinais e transversais da pista, e a variação da trajetória do veículo dentro da curva. Os resultados obtidos demonstram que os critérios de projeto atuais não garantem a segurança de semi-reboques em curvas descendentes de raio mínimo, principalmente nas curvas de menor velocidade. O critério desenvolvido permite o estabelecimento de margens de segurança para a regulamentação de velocidade em curvas horizontais descendentes já existentes, bem como possibilita a determinação da velocidade de projeto segura para curvas descendentes em novas vias.The grade effect on highway horizontal curves is notorious for traffic accidents because automobiles tend to skid and leave the road whereas commercial loaded vehicles tend to roll over. The standard criteria for the geometric design of these curves, which are considered flat, ignore the heavy vehicles propensity for rollover by relying solely on the forces of lateral friction and on the road superelevation in order to keep the vehicle in a safe trajectory. The current study has been set out in order to develop a model that will yield margins of safety to prevent skidding and rollover of heavy vehicles (semi-trailers) on horizontal descending highway curves. The model proposed in the present study is sensitive to safety variables both intrinsic and extrinsic to the vehicles, including longitudinal and transversal characteristics of the road, and vehicles trajectory variations at horizontal curves. The results of the study show that the currently adopted safety guidelines do not guarantee the safety of such articulated vehicles on grade curves with minimum radii, mostly at lower speeds curves. As a result, the proposed criteria allows the establishment of margins of safety that can be applied to regulatory speed signs on existing horizontal descending curves, and for the setting of safe design speeds for descending curves on new highways.
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Lorio, Berino. "Towards a non-intrusive traffic surveillance system using digital image processing." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52589.
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Thesis (MScEng)--Stellenbosch University, 2001.ENGLISH ABSTRACT: With the increased focus on the use of innovative and state-of-the-art technology in Intelligent Transport Systems (ITS), the need for more accurate and more detailed road traffic flow data has become apparent. Data obtained from vehicle detector loops, which merely act as vehicle presence sensors, is neither reliable nor accurate enough anymore. This type of sensor poses the problem that it has to be inserted into the road surface; temporarily obstructing traffic flows, and has to be replaced after pavement reconstruction. One of the solutions to this problem is to develop a traffic surveillance system that uses video image processing. In cities where Intelligent Transport Systems are used extensively, roadways are monitored through Closed Circuit Television Cameras (CCTV) that are closely watched by traffic control centre personnel. These cameras are mounted on posts on the roadside. These cameras can serve a dual purpose, being used for both human monitoring and as inputs to Video Image Processing Systems. In this study some of the digital image processing techniques that could be used in a traffic surveillance system were investigated. This report leads the reader through the various steps in the processing of a scene by a traffic surveillance system based on feature tracking, and discusses the pitfalls and problems that are experienced. The tracker was tested using three image sequences and the results are presented in the final chapter of this report.
AFRIKAANSE OPSOMMING: Met die toenemende fokus op die gebruik van innoverende oplossings en gevorderde tegnologie in Intelligente Vervoerstelsels, het die noodsaaklikheid van akkurater en meer gedetailleerde padverkeer vloeidata duidelik geword. Data wat verkry word d.m.v. voertuig deteksie lusse, wat alleenlik voertuig teenwoordigheid/afwesigheid meet, is nie meer akkuraat of betroubaar genoeg nie. Hierdie tipe sensors het egter die nadeel dat dit in die plaveisel ingesny moet word, dus vloei tydelik kan belemmer, en moet vervang word elke keer as plaveisel rekonstruksie gedoen word. Een van die oplossings vir hierdie probleem is om 'n verkeers waarnemingstelsel te ontwikkel wat van videobeeldverwerking gebruik maak. In stede waar van uitgebreide intelligente verkeerstelsels gebruik gemaak word, word paaie gemonitor d.m.v. geslote baan televisiekameras wat op pale langs die paaie aangebring is. Personeellede van die verkeers beheer sentrum hou dan die inkomende televisiebeelde dop. Hierdie kameras kan 'n dubelle rol vervul deurdat dit vir beide menslike waarneming en as invoer in 'n video-beeldverwerking stelsel gebruik kan word. In hierdie studie was verskeie digitale beeldverwerking tegnieke wat gebruik kan word in 'n verkeers waarnemingstelsel ondersoek. Hierdie verslag lei die leser deur die verskeie stappe in die verwerking van 'n toneel deur 'n verkeers waarneming stelsel wat gebaseer is op die volg van kenmerke. Die verslag beskryf ook die slaggate en probleme wat ondervind word. Die voertuig volger was getoets deur van drie reekse beelde gebruik te maak en die resultate word weergegee in die finale hoodfstuk van hierdie verslag.
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jia, jianmin. "Multi-Criteria Evaluation in Support of the Decision-Making Process in Highway Construction Projects." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3202.
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The decision-making process in highway construction projects identifies and selects the optimal alternative based on the user requirements and evaluation criteria. The current practice of the decision-making process does not consider all construction impacts in an integrated decision-making process. This dissertation developed a multi-criteria evaluation framework to support the decision-making process in highway construction projects. In addition to the construction cost and mobility impacts, reliability, safety, and emission impacts are assessed at different evaluation levels and used as inputs to the decision-making process.
Two levels of analysis, referred to as the planning level and operation level, are proposed in this research to provide input to a Multi-Criteria Decision-Making (MCDM) process that considers user prioritization of the assessed criteria. The planning level analysis provides faster and less detailed assessments of the inputs to the MCDM utilizing analytical tools, mainly in a spreadsheet format. The second level of analysis produces more detailed inputs to the MCDM and utilizes a combination of mesoscopic simulation-based dynamic traffic assignment tool, and microscopic simulation tool, combined with other utilities.
The outputs generated from the two levels of analysis are used as inputs to a decision-making process based on present worth analysis and the Fuzzy TOPSIS (Technique for Order Preference by Similarity to Ideal Situation) MCDM method and the results are compared.
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Bruce, Edward L. "An enhanced methodology for quantifying Urban freeway congestion and its uses within the congestion management system." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/21259.
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Ni, Daiheng. "Extension and generalization of Newell's simplified theory of kinematic waves." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-11112004-112805/unrestricted/ni%5Fdaiheng%5F200412%5Fphd.pdf.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2005.Leonard, John D., Committee Chair ; Goldsman, Dave, Committee Member ; Amekudzi, Adjo, Committee Member ; Hunter, Michael, Committee Member ; Dixon, Karen, Committee Member. Vita. Includes bibliographical references.
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Tamayo, Cascan Edgar. "Towards using microscopic traffic simulations for safety evaluation." Thesis, KTH, Fordonsdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-243486.
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Microscopic traffic simulation has become an important tool to investigate traffic efficiency and road safety. In order to produce meaningful results, incorporated driver behaviour models need to be carefully calibrated to represent real world conditions. In addition to macroscopic relationships such as the speed-density diagram, they should also adequately represent the average risk of accidents occurring on the road. In this thesis, I present a two stage computationally feasible multi-objective calibration process. The first stage performs a parameter sensitivity analysis to select only parameters with considerable effect on the respective objective functions to keep the computational complexity of the calibration at a manageable level. The second stage employs a multi-objective genetic algorithm that produces a front of Pareto optimal solutions with respect to the objective functions. Compared to traditional methods which focus on only one objective while sacrificing accuracy of the other, my method achieves a high degree of realism for both traffic flow and average risk.Mikroskopisk trafiksimulering har blivit ett viktigt verktyg för att undersöka trafik effektivitet och trafiksäkerhet. För att producera meningsfulla resultat måste inbyggda drivrutinsbeteendemodeller noggrant kalibreras för att representera verkliga förhållanden i världen. Förutom makroskopiska relationer, såsom hastighetsdensitetsdiagrammet, bör de också på ett adekvat sätt representera den genomsnittliga risken för olyckor som uppträder på vägen. I denna avhandling presenterar jag en tvåstegs beräkningsberättigbar mångsidig kalibreringsprocess. Det första steget utför en parameterkänslighetsanalysför att bara välja parametrar med stor effekt på respektive objektiv funktioner för att hålla kalibrerings komplexiteten på en hanterbar nivå. Det andra steget använder en mångriktig genetisk algoritm som ger framsidan av Pareto optimala lösningar med hänsyn till objektivfunktionerna. Jämfört med traditionella metoder som fokuserar på endast ett mål, samtidigt som man offrar den andra, ger min metod en hög grad av realism för både trafikflöde och genomsnittlig risk.
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Twagirimana, Janvier. "Establishing and applying speed-flow relationships for traffic on rural two-lane two- way highways in the Western Cape." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85825.
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Thesis (MScEng)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: Speed-flow-density relationships are the most useful tools in the highway design and planning process. They are useful in predicting the roadway capacity, in determining the adequate level-of-service of traffic flow and in determining travel time for a given roadway. Two-lane two-way rural highways constitute the vast majority of the rural road network in South Africa. Nowadays in the Western Cape and other provinces of South Africa, the speed-flow-density relationships normally used for rural transportation studies are derived from the Highway Capacity Manual, which reflects the traffic conditions in the North American situation. Since the North American traffic conditions may be different from the South African conditions, a need to investigate speed-flow-density relationships on these highways in South Africa arises in order to justify any investment made on these roads. In this context, a video technique was used to collect traffic flow data during morning peak hours on two rural two-lane two-way highways in the Western Cape Province in order to investigate these relationships. Through the use of Adobe premiere C.S 6 software, travel time of individual vehicles and distance headways were measured and used in computation of average speed and average density. Several researchers have developed models to describe the relationships between traffic characteristics on uninterrupted flow facilities. In this study, some of these models were tested using collected data in order to investigate which model fits the data satisfactorily. Statistical methods were used to evaluate the ability of each model to predict the flow characteristics over the whole range of data. Average speed and density data were used through regression analysis to perform curve fitting and testing of these developed models. In the next stage, the model which provided a best representation of the data on each section was selected and through the application of the steady-state equation (2.1), flow-density and speed-flow relationships were established on these sections. The available data were also used to investigate the impact the observation time has on the speed-flow curve and the resulting capacity value. Finally, the developed speed-flow curves were used to determine the capacities of the study sections. These capacity values were used to determine if the shoulder usage contributes in increasing the capacity of two-lane two-way highways by comparing them to the capacity provided by HCM.
AFRIKAANSE OPSOMMING: Spoed-vloei-digtheid verhoudings is baie handig in die beplanning en ontwerp van paaie. Dit kan ook gebruik word in die voorspelling van kapasiteit, diensvlak en reistyd. Twee-laan twee-rigting paaie maak die grootste deel van die Suid-Afrikaanse padnetwerk uit en vir die beplanning daarvan word van Amerikaanse spoed-vloei-digtheid verhoudings gebruik gemaak aangesien daar nog nie voorheen ‘n studie hiervan in SA gemaak is nie. Video-opnames is gebruik om verkeersvloeidata op twee paaie in die omgewing van Stellenbosch te versamel. Die reistyd en digtheid van individuele voertuie is tydens spitstye waargeneem. Die data is gebruik om te bepaal watter modelle die beste is om die spoed-vloei-digtheid verhoudings vir hierdie paaie te modelleer. Die beste modelle is dan gebruik om die kapasiteit van die paaie te bepaal en dit te vergelyk met die Amerikaanse waardes.
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Bowie, Jeanne Marie. "Efficacy of Speed Monitoring Displays in Increasing Speed Limit Compliance in Highway Work Zones." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd229.pdf.
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Sengupta, Sudipta 1974. "Efficient and robust routing of highly variable traffic." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/35532.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2006.Includes bibliographical references (p. 316-324).
Many emerging applications for the Internet are characterized by highly variable traffic behavior over time that is difficult to predict. Classical approaches to network design rely on a model in which a single traffic matrix is estimated. When actual traffic does not conform to such assumptions, desired bandwidth guarantees cannot be provided to the carried traffic. Currently, Internet Service Providers (ISPs) use gross capacity over-provisioning and manual routing adaptation to avoid network congestion caused by unpredictable traffic. These lead to increased network equipment and operational costs. Development of routing infrastructures that optimize network resources while accommodating extreme traffic unpredictability in a robust and efficient manner will be one of the defining themes in the next phase of expansion of the Internet. This thesis proposes two-phase routing as a capacity efficient and robust strategy for handling highly variable traffic. The scheme allows preconfiguration of the network such that all traffic patterns permissible within the network's natural ingress-egress capacity constraints can be routed with bandwidth guarantees without requiring detection of traffic changes in real-time or reconfiguring the network in response to it.
(cont.) The scheme routes traffic in two phases -- traffic entering the network is sent from the source to a set of intermediate nodes in predetermined split ratios that depend on the intermediate nodes, and then from the intermediate nodes to the final destination. The scheme has the desirable properties of supporting static optical layer provisioning in IP-over-Optical networks and indirection in specialized service overlay models unlike previous approaches -- like direct source-destination path routing - for handling variable traffic. This thesis represents the first comprehensive study, problem formulation, and algorithm design for many aspects of two-phase routing. Our contributions can be grouped into three broad parts. First, we consider the problems of minimum cost network design and maximum throughput network routing for the scheme. We give a simple solution for minimum cost network design. For maximum throughput network routing. we design linear program.ling based and combinatorial algorithms. We show how the algorithms can handle a total cost constraint for maximum throughput two-phase routing. This can be used to solve the link capacitate version of minimum cost two-phase routing.
(cont.) We establish theoretical bounds on the resource requirements of two-phase routing under throughput and cost models with respect to the optimal scheme that is allowed to make the routing dynamically dependent on the current traffic matrix. We also generalize the traffic split ratios to depend not only on the intermediate nodes but also on source and destination of traffic and solve the corresponding optimization problems. Second, we consider making two-phase routing resilient to network failures. Two-phase routing in IP-over-Optical networks can be protected against router node failures through redistribution of traffic split ratio for the failed router node to other intermediate nodes. We propose two different schemes for provisioning the optical layer to handle router node failures. We develop linear programming formulations for both schemes and a fast combinatorial algorithm for the second scheme so as to maximize network throughput. Two-phase routing can be made resilient against link failures by protecting the first and second phase paths using pre-provisioned restoration mechanisms. We consider three such restoration mechanisms - local (link/span) restoration, K-route path restoration, and shared backup path restoration.
(cont.) We provide linear programming formulations and combinatorial algorithms for maximum throughput two-phase routing with local restoration and K-route path restoration. We show that the problem of maximum throughput two-phase routing with shared backup path restoration is JVP-hard. Assuming an approximation oracle for a certain disjoint paths problem (which we also show to be AP-hard), we design a combinatorial algorithm with provable guarantees. Third, we consider the application of two-phase routing to multi-hop Wireless Mesh Networks (WMNs). These networks have recently been of much research interest due to their lowered need for wired infrastructure support and due to envisaged new applications like community wireless networks. We extend our optimization framework for maximum throughput two-phase routing in wired networks to handle routing and scheduling constraints that are peculiar to WMNs and arise from the requirement to handle radio transmit/receive diversity and the phenomenon of wireless link interference. We evaluate various aspects of two-phase routing on actual ISP topologies using the developed algorithms. For the WMN application, we use randomly generated WMN topologies for the evaluations.
by Sudipta Sengupta.
Ph.D.
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Sin, Jerome Ga Nok. "Safety impact study of centerline rumble strips in Georgia." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51775.
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Within the last decade, centerline rumble strips have become increasingly prevalent as a safety countermeasure on undivided roadways throughout the United States. Within the state of Georgia, nearly 200 miles of centerline rumble strips have been installed in an effort to address the severity and frequency of crashes involving the centerline. With several thousands of miles of new installations throughout the nation in the last decade, much literature on this subject is still being amassed. This paper will compile and summarize existing literature in order to provide a thorough overview of the latest information from around the United States regarding the safety, usage, and impacts of centerline rumble strips. Furthermore, this paper seeks to comprehensively determine the safety impacts of centerline rumble strips on undivided, rural highway facilities in the state of Georgia. This portion of the study will prepare an updated inventory of centerline rumble strip installations in Georgia and perform a before-after study using three methods: a direct before-after analysis, a comparison before-after analysis, and a comparative analysis. These analyses will incorporate data from crash databases, police records, and traffic records to produce results unique to Georgia. Lastly, this paper will determine the current status of centerline rumble strips and the potential short- and long-term safety, physical, and unintended effects of centerline rumble strips both in the state of Georgia and throughout the United States through a survey sent to all fifty state transportation agencies. Through literature compilation, safety analyses, and findings on the effects of centerline rumble strips, this paper will aid in the future of centerline rumble strips within Georgia and the United States.
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Lin, Kai-Jui. "Influence of weather conditions on the propagation of highway noise at sites with barriers." Ohio : Ohio University, 2000. http://www.ohiolink.edu/etd/view.cgi?ohiou1172598982.
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Pratyaksa, Prabha. "Safety evaluation of converging chevron pavement markings." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47697.
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Chevron pavement markings have seen rising interest in the United States as a means to reduce speeds at high-speed locations and improve safety performance. In Atlanta, there are two freeway-to-freeway ramps where chevron markings are being used. A previous study analyzed before-and-after speed data at these ramps and found only a modest reduction on overall vehicle speeds. However, a cursory crash analysis indicated that the ramps had crash reductions of over 60%, suggesting that safety benefits exist even though vehicle speeds are not significantly affected. This research aims to evaluate the safety performance of chevron markings on the two ramps in Atlanta, GA in order to quantify the potential impact of the treatment on safety and to understand the mechanism by which the treatment influences safety.
This thesis begins with a literature review covering topics in human factors in safety, past uses of different types of pavement markings, and methods in using crash databases and police reports in accident studies. Next, the thesis presents an in-depth before and after analysis of crash data from crash databases and police reports provided by the Georgia Department of Transportation. And finally, the thesis concludes with a summary of findings and a discussion of further research needs.
The results verified that there were 73% and 61% crash reductions in the two study ramps. Chevron markings appear to have benefitted all types of crashes and that they are possibly serving as a warning to drivers of potential upcoming hazards. Unavailability of a number of police reports and errors in crash databases were limitations to this study, and ultimately, new sites should be selected carefully and further studies need to be performed to better understand the treatment's benefits.
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Roux, Jacques. "Establishing and applying speed-flow relationships for traffic on South African freeways." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52261.
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Thesis (MEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: Peak mornmg traffic-flow data were obtained from video footage of three representative freeway sections on the Nl and N2 westbound towards Cape Town. Flow, speed, and density measurements were made from the footage with the aid of a stopwatch. Many researchers (2-12) have originated and developed models to describe the relationships between traffic flow characteristics (speed, flow, and density) on freeways. In this report, a number of these models have been investigated with data obtained from South African freeways. The ability of each model to predict flow parameters over the entire range of data was evaluated with the aid of statistical methods. The tests were performed by regressing average speed vs. average density. Flow-density and speed-flow relationships were derived through application of the steady-state equation (2.6). In each case, a final model was chosen through visual inspection that consisted of two separate curves, one for the uncongested flow regime and one for the congested flow regime. Furthermore, speed-flow relationships were examined for individual lanes and compared to relationships established for average lanes. The models were also compared to models obtained from overseas studies (1,16,19) as well as from studies done locally (17). A secondary objective of this study is to investigate the performance of existing freeway facilities through application of the relevant models to the traffic-flow data of a particular facility. The current peak-morning performance of the N2 freeway section is investigated in terms of travel-time and travel cost. The particular study section consists of three lanes, the right hand lane being an HOY lane dedicated to taxis and buses. Different hypothetical cases are investigated. The first hypothetical case is an investigation into the traffic situation on the freeway section without the influence of the HOY lane. The second hypothetical case investigates the traffic situation on the section with perfect operation of the HOY lane. The current performance of the N2 section is compared to the performance of each of the hypothetical cases.
AFRIKAANSE OPSOMMING: Oggend-spits verkeersvloei data is verkry vanaf drie verteenwoordigende seksies op die Nl en N2 deurpaaie naby Kaapstad met die gebruik van 'n video kamera. Vloei, spoed, end digtheid opnames is gemaak met behulp van 'n stophorlosie. Verskeie navorsers (2-12) het modelle gepostuleer en ontwikkelom die verhoudings tussen verkeersvloei eienskappe (spoed, volume, en digtheid) op deurpaaie te beskryf. In hierdie verslag word 'n aantal van hierdie modelle ondersoek met data wat verkry is van Suid-Afrikaanse deurpaaie. Die vermoë van elke model om vloei eienskappe oor die hele bestek van die data te voorspel is geëvalueer met behulp van statistiese metodes. Statistiese toetse behels 'n regressie analise van gemiddelde spoed teenoor gemiddelde digtheid. Volume-digtheid en spoed-volume verwantskappe is direk afgelei vanaf Vergelyking 2.6. Vir elke geval is 'n finale model m.b.v. visuele inspeksie gekies wat bestaan het uit twee afsonderlike kurwes, een kurwe vir die vryvloei regime en 'n ander kurwe vir hoë-digtheid toestande. Verder word spoedvolume verwantskappe vir afsonderlike deurpad-lane ondersoek en vergelyk met verwantskappe wat verkry is vir gemiddelde lane. Die modelle word ook vergelyk met modelle wat verkry is vanaf oorsese studies (1,16,19), sowel as met modelle wat plaaslik verkry is (17). 'n Sekondêre doel van hierdie studie is om die prestasie van bestaande deurpadfasiliteite te ondersoek deur die verskillende modelle aan te wend tot die verkeersvloei data van 'n betrokke fasiliteit. Die prestasie van die N2 deurpad seksie gedurende oggend-spits verkeer is ondersoek in terme van reistyd en ryskoste. Die betrokke seksie bestaan uit drie lane, waarvan die regter laan gereserveer is vir busse en taxis. Verskeie hipoteses is ook ondersoek. Die eerste hipotese is 'n ondersoek na die verkeers-vloei kondisie op die seksie sonder die invloed van die bus- en taxi-laan. Die tweede hipotese ondersoek die seksie met perfekte werking van die bus- en taxilaan. Die huidige prestasie van die N2 seksie is vergelyk met die prestasie van elk van die hipoteses.
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Haldane, Mandy Jaye. "Assessing the impacts of multi-combination vehicles on traffic operation." Thesis, Queensland University of Technology, 2002. https://eprints.qut.edu.au/36180/1/36180_Haldane_2002.pdf.
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The Australian road freight industry is moving towards improved efficiency and
competitiveness through the use of larger and more innovative multi-combination
vehicles (MCVs). However, this move has brought about concern over the interaction of
these new vehicles with the environment, existing infrastructure and other road users.
The aim of this research project was to assess the impacts of MCVs on traffic operation
and safety. This was undertaken by initially reviewing cunent literature on MCVs. It
was recognised that the Australian heavy vehicle fleet had modernised since a number of
performance levels were established and the review highlighted the need for greater
research to obtain current data and either develop new performance levels or validate
previous research.
This study selected four characteristics for analysis: passenger car equivalence (PCE),
clearance time, acceleration, and tracking ability on a straight path. These
characteristics were considered to be the most influential on the interaction between
MCVs and other road users. Vehicle operational data was collected between April and
August 2001, for each characteristic, via a series of three in-field test programs located
on controlled road sections in Queensland: south of Charters Towers; west of
Toowoomba; and at the Mount Cotton Training Centre, south-east of Brisbane.
All tested MCVs recorded a PCE greater than 2 for a through-movement on a flat grade
with no adjacent traffic lanes. It was determined that assuming a constant PCE does not
account for the variation in values attained for different MCV types. Under
circumstances where MCV volumes are significant, it would be more accurate to
establish the average PCE value of each relevant movement at the intersection based on
PCEs across the traffic spectrum and using the values provided in Table 5.4. Further
testing is needed to establish PCE values on grades, turning movements, non-standard
lane widths, and for vehicles such as Double Road Trains, AB-Triples and AAB-Quads. The intersection clearance time characteristics proposed by NRTC (2001) were found to
be conservative for the MCV s tested. To cover a greater range of operating conditions,
clearance time requirements for a MCV on a particular grade may be derived from the
trajectory curves provided in Figures 6.3 to 6.6. Further in-field testing should be
undertaken to obtain additional trajectory curves for MCVs with lower powered engines.
Speed curves were developed (Figures 6.9 to 6.12) which may be used with the above
trajectory curves to derive vehicle speeds at specific distances, on particular grades.
This would enable assessors to determine the minimum entry lane length required to
allow a MCV to attain adequate speed to merge into moving traffic, and also indicate
whether an overtaking lane is required on a steep ascending grade. Further testing
should be undertaken to establish speed curves over a higher speed and distance range .
. Queensland Department of Main Roads (1998b) recommended an average acceleration
rate for use in sight distance calculations. This was found from testing to be generally
conservative for a B-Double, although too high for all the other MCVs tested. The
trajectory curves provided in Figures 6.15 to 6.18 were developed to examine the
variation in acceleration as test vehicles depart from rest. These may be used to
determine average acceleration rates, over specific distances and on particular grades.
Alternatively, sight distance requirements may be determined from equation (6.9), using
clearance times established from equation (6.5) or Figures 6.3 to 6.6.
Data on tracking ability of MCVs on a straight path was collected. It is recommended
that further work be conducted to analyse the data, determine lane width requirements,
and variations in tracking ability between separate trailers. The findings should be
compared with Prem et al. (2000) and NRTC (2001) values. Further work is also
required to identify which factors most influence lateral displacement of the rear trailer.
It is expected that the research findings will be used to inform development of
Queensland Department of Main Roads' Route Assessment Guidelines and potentially
those of other authorities.
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Sundarram, Satyanarayan. "A software package for the analysis of the severity of blockage of traffic signs during daytime for drivers of cars following trucks on urban highways." Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1178040231.
Full text
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Amaya, Segura Sebastian, and Kristofer Snarberg. "En utredning angående ett snabbt cykelstråk längs Vätterns södra strand." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Byggnadsteknik och belysningsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-40955.
Full textAbstract:
Syfte: För att göra det mer attraktivt att använda cykeln som transportmedel har flertalet städer uppgraderat till snabba cykelstråk. Ett snabbt cykelstråk tillåter cyklister att färdas på ett snabbt sätt på grund av utformningens kvaliteter. Flertalet undersökningar pekar på det snabba cykelstråkets inverkan att använda cykeln i större utsträckning. Målet med arbetet är utreda ett snabbt cykelstråk längs Vätterns södra strand enligt Jönköpings kommuns mål och med hänsyn till cyklisters preferenser. För att uppnå målet utformas ett förslag till hur ett snabbt cykelstråk kan se ut, målet bryts ned i tre frågeställningar: Purpose: In order to make it more attractive to use the bike as a means of transport, several cities have upgraded their bicycle tracks to bicycle highways. A bicycle highway allows cyclists to travel fast due to the qualities of the design. Several studies shows the impact of the bicycle highway considering a higher rate of bicycle usage. The aim of the thesis is to investigate a bicycle highway along the south beach of Vättern and its impact according to the objectives set by the municipality of Jönköping. A design proposal is thereafter being made, according to cyclists´ preferences and the objectives and conditions of the municipality of Jönköping, broken down into three issues:
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Sulaeman, Adika Bintang. "A Highly-Available Multiple Region Multi-access Edge Computing Platform with Traffic Failover." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-285521.
Full textAbstract:
One of the main challenges in the Multi-access Edge Computing (MEC) issteering traffic from clients to the nearest MEC instances. If the nearest MECfails, a failover mechanism should provide mitigation by steering the trafficto the next nearest MEC. There are two conventional approaches to solve thisproblem, i.e., GeoDNS and Internet Protocol (IP) anycast. GeoDNS is notfailover friendly because of the Domain Name System (DNS) cache lifetime.Moreover, the use of a recursive resolver may inaccurately translate the IPaddress to its geolocation. Thus, this thesis studies and proposes a highlyavailable MEC platform leveraging IP anycast. We built a proof-of-conceptusing Kubernetes, MetalLB, and a custom health-checker running on theGNS3 network emulator. We measured latency, failure percentage, and MeanTime To Repair (MTTR) to observe the system’s behavior. The performanceevaluation of the proposed solution shows an average recovery time betterthan one second. The number of failed requests and latency overhead growslinearly as the failover time and latency between two MECs increases. Thisthesis demonstrates the effectiveness of IP anycast for MEC applications tosteer the traffic to the nearest MEC instance and to enhance resiliency withminor overhead.n av de största utmaningarna i Multi-access Edge Computing (MEC) är attstyra trafiken från klienter till närmaste MEC instanser. Om den närmasteMEC misslyckas, bör en failover-mekanism ge begränsning genom att styratrafiken till nästa närmaste MEC. Det finns två konventionella metoder för attlösa detta problem, dvs GeoDNS och IP anycast. GeoDNS är inte failovervänligtpå grund av DNS-cache-livslängd. Dessutom kan användningen aven rekursiv upplösare felaktigt översätta IP-adressen till dess geolokalisering.Således studerar och föreslår denna avhandling en mycket tillgänglig MEC-plattform som utnyttjar IP anycast. Vi byggde ett proof-of-concept medKubernetes, MetalLB och en anpassad hälsokontroll som körs på GNS3-nätverksemulatorn. Vi mätte latens, felprocent och Mean Time To Repair(MTTR) för att observera systemets beteende. Prestationsutvärderingen avden föreslagna lösningen visar en genomsnittlig återhämtningstid som ärbättre än en sekund. Antalet misslyckade förfrågningar och latensomkostnaderväxer linjärt när failover-tiden och latensen mellan två MEC ökar. Den häravhandlingen visar effektiviteten hos IP anycast för MEC-applikationer för attstyra trafiken till närmaste MEC instans och för att förbättra elasticiteten medmindre overhead.
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Wei, Zheng S. M. Massachusetts Institute of Technology. "Critical enhancements of a dynamic traffic assignment model for highly congested, complex urban network." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/58283.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 109-115).
To accurately replicate the highly congested traffic situation of a complex urban network, significant challenges are posed to current simulation-based dynamic traffic assignment (DTA) models. This thesis discusses these challenges and corresponding solutions with consideration of model accuracy and computational efficiency. DynaMITP, an off-line mesoscopic DTA model is enhanced. Model success is achieved by several critical enhancements aimed to better capture the traffic characteristics in urban networks. A Path-Size Logit route choice model is implemented to address the overlapping routes problem. The explicit representation of lane-groups accounts for traffic delays and queues at intersections. A modified treatment of acceptance capacity is required to deal with the large number of short links in the urban network. The network coding is revised to maintain enough loader access capacity in order to avoid artificial bottlenecks. In addition, the impacts of bicycles and pedestrians on automobile traffic is modeled by calibrating dynamic road segment capacities. The enhanced model is calibrated and applied to a case study network extracted from the city of Beijing, China. Data used in the calibration include sensor counts and floating car travel time. The improvements of the model performance are indicated by promising results from validation tests.
by Zheng Wei.
S.M.
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Alkadri, Mohamed Yaser. "Freeway Control Via Ramp Metering: Development of a Basic Building Block for an On-Ramp, Discrete, Stochastic, Mesoscopic, Simulation Model within a Contextual Systems Approach." PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/1308.
Full textAbstract:
One of the most effective measures of congestion control on freeways has been ramp metering, where vehicle entry to the freeway is regulated by traffic signals (meters). Meters are run with calibrated influx rates to prevent highway saturation. However, recent observations of some metering sites in San Diego, CA indicate that metering, during peak hour demand, is helping freeway flow while sometimes creating considerable traffic back-ups on local streets, transferring congestion problems from the freeway to intersections. Metering problems stem largely from the difficulty of designing an integrated, dynamic metering scheme that responds not only to changing freeway conditions but also to fluctuating demand throughout the ramp network; a scheme whose objective is to maintain adequate freeway throughput as well as minimize disproportionate ramp delays and queue overspills onto surface streets. Simulation modeling is a versatile, convenient, relatively inexpensive and safe systems analysis tool for evaluating alternative strategies to achieve the above objective. The objective of this research was to establish a basic building block for a discrete system simulation model, ONRAMP, based on a stochastic, mesoscopic, queueing approach. ONRAMP is for modeling entrance ramp geometry, vehicular generation, platooning and arrivals, queueing activities, meters and metering rates. The architecture of ONRAMP's molecular unit is designed in a fashion so that it can be, with some model calibration, duplicated for a number of ramps and, if necessary, integrated into some other larger freeway network models. SLAM.II simulation language is used for computer implementation. ONRAMP has been developed and partly validated using data from eight ramps at Interstate-B in San Diego. From a systems perspective, simulation will be short-sided and problem analysis is incomplete unless the other non-technical metering problems are explored and considered. These problems include the impacts of signalizing entrance ramps on the vitality of adjacent intersections, land use and development, "fair" geographic distribution of meters and metering rates throughout the freeway corridor, public acceptance and enforcement, and the role and influence of organizations in charge of decision making in this regard. Therefore, an outline of a contextual systems approach for problem analysis is suggested. Benefits and problems of freeway control via ramp metering, both operational short-term and strategic long-term, are discussed in two dimensions: global (freeway) and local (intersection). The results of a pilot study which includes interviews with field experts and law enforcement officials and a small motorist survey are presented.
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Lim, David Eng Chung. "Investigation in to ramp queues vs. freeway queues on ramp metered freeways." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/1676.
Full textAbstract:
Freeways and highways form an integral part of any road network system demanding significant quantities of resources to plan and construct. During times of congestion and flow breakdown forms of traffic management are required to maintain the efficiency, reliability and safety of these high asset road facilities. Here within lies the responsibilities of traffic engineering professionals. The lack of adequate maintenance and management of any urban road network system hinders economic development and quality of life.Ramp metering is an active traffic management system implemented on high speed, free flowing facilities such as freeways and highways. This form of intelligent transport system has been applied to freeways throughout the world to regulate the intensity and demand proportion of freeway inflow during peak demand periods. The primary goal is to manage the existing roadway to operate at maximum efficiency. Main Roads Western Australia, the governing road authority in Western Australia is currently in a position to investigate the suitability of ramp metering on Western Australia's freeways.This research demonstrates how traffic movement and interaction can be mapped and characterised to identify forms of traffic flow breakdown that ramp metering has the potential to address. This research also documents the required components of ramp metering, how it should operate and the potential this active management system has to be applied over a system wide road network infrastructure.The Mitchell Freeway southbound direction undergoes significant forms of congestion and traffic flow breakdown during the morning peak period. A traffic characteristic of the Mitchell Freeway was developed to make an evaluation for the suitability of ramp metering as an effective management system. An analytical comparison between current freeway queues and theoretical on-ramp queues provided indication that the congestion and flow breakdown currently observed had the potential to be managed through ramp metering, ensuring the future sustainability of this vital freeway for the city of Perth, Western Australia.
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Nordén, Catharina. "Effektbelysning i trafikmiljö." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Belysningslära, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36494.
Full textAbstract:
Examensarbetet genomfördes vid Jönköping University i samband med Ljusdesign utbildningen år 2017. Undersökningen avsåg att undersöka trafikmiljön utmed motorvägen mellan Värnamo och Jönköping, för att kunna kartlägga och få en uppfattning av hur effektbelysningen där kan användas med färgat ljus utan att skapa en fara i trafiken. Målet var att undersöka om effektbelysningarna visade en påverkan på bilförarnas upplevelse av motorvägen, samt om färgerna gav en skillnad i upplevelsen eller skapade distraktioner. Området var aktuellt att undersöka eftersom effektbelysningar utmed vägar blir alltmer vanliga efter teknologin inom belysning blivit mer användbar och ekonomiskt försvarbar. Av det skälet blir effektbelysningar av färg vanliga men antas också ge en påverkan i trafiken som vi inte är medvetna om. Studiens frågeställningar formulerades därefter och undersökte hur effektbelysning på objekt påverkar bilförares upplevelse i trafiken. Samt om effektbelysning av färg och neutralt ljus påverkade upplevelsen olika.Fältstudien genomfördes under tre kvällar i mars månad på en bensinstation i anknytning till sträckan som undersöktes. Deltagarna svarade på ett frågeformulär med semantiska skalor där de fyllde i hur de känt sig och upplevt vägsträckan de hade kört. Av deltagarna tillfrågades slumpmässiga uttagna personer om de kunde svara på följdfrågor i form av en intervju. På sträckan fanns sju stycken effektbelysningar varav tre hade färgat ljus. Resultaten visade att effektbelysningen på objekten fångade bilförarnas uppmärksamhet och påverkade bilförarnas upplevelse av vägsträckan. Studien visade även att förarna påverkades olika av effektbelysningarna beroende på om ljussättningen var av färgat eller neutralt ljus. Slutsatserna av undersökningen visar hur förarna i denna studie upplevde sträckan mellan Jönköping och Värnamo. För att konstatera hur belysta objekt generellt påverkar trafiksäkerheten krävs mer forskning.The thesis was conducted at Jönköping University in conjunction with the lighting design education in year 2017. The study aimed at investigating the traffic environment along the high way between Värnamo and Jönköping in order to map and get an idea of how the effect lighting can be used with colored light without creating a danger to traffic. The aim was to investigate whether the effect lights showed an impact on the driver's perception of the highway, and if the colors gave a difference in the experience or created distractions. The area was relevant to investigate as effect lighting are becoming more common after the technology has become more useful and economically justifiable. For that reason effect lighting with color are becoming more common, but are believed to have an impact on traffic that we are not aware of. The thesis questions were then formulated and investigated how effect lighting on objects affects drivers' experience in traffic. As well as if effect lighting of color and neutral light affect drivers’ experience of the road differently.The field study was conducted for three nights in March at a gas station related to the route that was investigated. Participants answered questions with semantic scales where they answered how they felt and experienced the road. Some of the participants were also randomly picked and asked if they could answer any following questions in the form of an interview.The road that was investigated had seven different effect lightings, witch three of them had colored light. The results showed that the lighting on the objects caught the attention of car drivers and affected the road drivers' experience of the road. The study also showed that the drivers were affected differently by the effect lights depending on whether the lighting was of colored or neutral light. The conclusions of the survey show how the drivers in this study experienced the road between Jönköping and Värnamo. To find out how effect lighting on objects generally affect road safety, more research is required.