Dissertations / Theses on the topic 'Traffic safety'
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1
Lam, Yat-wai. "Traffic safety and exposure." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43785633.
2
Lam, Yat-wai, and 林日威. "Traffic safety and exposure." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B43785633.
3
Wen, Keyao. "Traffic Accident Prediction Model Implementation in Traffic Safety Management." Thesis, Linköping University, Communications and Transport Systems, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-52203.
Abstract:
As one of the highest fatalities causes, traffic accidents and collisions always requires a large amounteffort to be reduced or prevented from occur. Traffic safety management routines therefore always needefficient and effective implementation due to the variations of traffic, especially from trafficengineering point of view apart from driver education.Traffic Accident Prediction Model, considered as one of the handy tool of traffic safety management,has become of well followed with interested. Although it is believed that traffic accidents are mostlycaused by human factors, these accident prediction models would help from traffic engineering point ofview to enlarge the traffic safety level of road segments. This thesis is aiming for providing a guidelineof the accident prediction model implementation in traffic safety management, regarding to trafficengineering field. Discussion about how this prediction models should merge into the existing routinesand how well these models would perform would be given. As well, cost benefit analysis of theimplementation would be at the end of this thesis. Meanwhile, a practical field study would bepresented in order to show the procedures of the implementation of traffic accident prediction model.The field study is about this commercial model set SafeNET, from TRL Limited UK, implemented inRoad Safety Audit procedures combined with microscopic simulation tool. Detailed processing andinput and output data will be given accompany with the countermeasures for accident frequencyreduction finalization.
4
Khalil, Issam, and Mohamed Morsi. "Collaborating vehicles for increased traffic safety." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-4223.
Abstract:
Transportation has expanded the scope of human mobility, increasing the distances we cover on a
regular basis. The large benefits of transportation have resulted in a huge recent increase in the
number of vehicles. This, however, implies an increased number of traffic accidents that cause
many fatalities and injuries every year. It also leads to problems like increased delay for
commuters, and negative effects on the environment. Not to mention, the money spent in the
wasted fuel, as well as the costs of fixing damaged equipment and property.
To help in mitigating these problems the vehicles and the road infrastructure should be equipped
with intelligent devices that allow them to communicate and collaborate with each other and
exchange safety information concerning accidents, road traffic conditions, and weather conditions
as well as non-safety information. Recently, this topic termed telematics has gathered
considerable interest constituting a lot of work and research all included under the title of
Intelligent Transportation System (ITS).
The thesis work defines general communication requirements of future telematics applications
and investigates various wireless carriers that are important to achieve communication inbetween
vehicles and between vehicles and nearby infrastructure. We analyse several future
applications related to the ITS field and describe their communication requirements. Based on the
communication requirements the applications are grouped into different profiles in order to
determine the most suitable carrier for each profile.
Disclaimer: This paper reflects only the authors’ views and the European Community (as cofounders
of the CVIS, SAFESPOT and PReVENT Sixth Framework Programme projects,
through the European Commission DG Information Society and Media) is not liable for any use
that may be made of the information contained within.
5
Lindberg, Gunnar. "Valuation and pricing of traffic safety /." Örebro : Universitetsbiblioteket : Örebro University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-787.
6
Sanne, Johan M. "Creating safety in air traffic control /." Lund : Arkiv, 1999. http://www.bibl.liu.se/liupubl/disp/disp99/arts193s.htm.
7
Hudson, Jacob D. "TRAFFIC SAFETY INVESTIGATIONS FOR LOCAL AGENCIES." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/411.
Abstract:
National and statewide (California) collision numbers are currently on the
decline; however, the U.S. is declining at a much slower rate than most other
developed countries, and in some aspects is actually regressing in terms of traffic
safety. Although state highway safety is improving, local roadway safety may
actually be regressing. Approximately three-quarters of all U.S. public roadways,
and approximately 80% of all injury accidents fall under the jurisdiction of cities.
However, cities may not be allocating the proper level of resources, or operating
under the proper administrative methodologies to adequately address these
safety issues.
This research finds that on average, California cities are experiencing
increasing annual collision rates. In particular, small cities with populations of
less than 25,000 are experiencing the largest increases, whereas larger cities are
experiencing static or slightly decreasing collision rates. California’s statewide
collision statistics and the administration surveys conducted as part of this study
indicate that there is a correlation between a city’s administrative
analysis/mitigation methodologies and their annual collision rate trends.
Specifically, cities with lower traffic engineering staff to population ratios tend to
have increasing collision rates, as opposed to cities with high staff to population
ratios, which have decreasing collision rates. Also, this research shows that cities
that allocate more traffic safety resources to enforcement over engineering tend
to have increasing collision rates, as opposed to cities allocating more resources
to engineering that have decreasing collision rates.
This research also finds that there are predominant and correctable
factors that lead to the various collision types. Cities that employ routine system
wide traffic safety audits addressing location-specific collision trends based on
these predominant factors tend to have decreasing collision rates, as opposed to
those that do not.
In general, collision rates among U.S. cities are increasing largely due to
increasing rates on roadways within the jurisdiction of smaller cities, most
commonly with populations under 25,000. Over one-third of cities are not staffed
at the proper levels, not allocating the necessary resources to traffic engineering
activities, and are not employing an adequate evaluation/mitigation strategy. The
findings of this study provide guidance and framework to cities for developing
effective traffic safety strategies by identifying the characteristics of those cities
that have been successful in reducing collision rates as examples. In particular
the value of this research is important for non-engineering administrative staff
and political bodies in terms of establishing appropriate staffing levels and
resource allocations necessary for an effective traffic safety program.
The findings of this study provide guidance and framework to cities for
developing effective traffic safety policy preference by identifying the
characteristics of those cities that have been successful in reducing collision
rates as examples. In particular this research is important for non-engineering
administrative staff and political bodies in terms of establishing appropriate
staffing levels and resource allocations necessary for a transportation
department to be effective in reducing traffic collisions and resulting damages.
8
Hung, Wing-kei, and 洪永淇. "A review of road safety strategies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B26791596.
9
Phiri, Mmakaki Dorothy. "Values and attitudes of primary school learners towards traffic safety and traffic safety education / Mmakaki Dorothy Phiri." Thesis, Potchefstroom University for Christian Higher Education, 2003. http://hdl.handle.net/10394/9971.
Abstract:
The main aim of the study was to determine values and attitudes of primary school
learners towards traffic safety and traffic safety education. The role played by parents
and teachers in developing positive values and attitudes towards traffic safety and
traffic safety education was determined. It was important to find out what can be
done by parents and school to teach traffic safety education to learners.
Key concepts like values, attitudes, traffic, safety and. education are discussed in
details in this study.
A group of learners was selected from fifteen primary schools in Potchefstroom to
conduct this study. The main aim was to determine their values and attitudes towards
traffic safety and traffic safety education. A questionnaire was developed whereby
learners, their parents and their teachers had to fill it out in order to reach the
objectives of this study.
From. the response of learners, it was evident that learners really value their safety
and that it is important for them to be safe road users. They even showed interest in
including road safety education in their school curriculum.
The school and parents also showed interest in traffic safety education being
included in their children's school curriculum. They even opted to help teaching their
children.
The response of the learners, teachers and parents was positive and this indicated
how possible it can be to implement/teach traffic safety education in schools.
The. study was successful and it is hoped that the teachers can use it to their own
benefit and to the benefit of their learners.Thesis (M.Ed.)--Potchefstroom University for Christian Higher Education, 2003
10
Campbell, Meredith L. "Determining the safety of urban arterial roads." Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0429104-144326.
11
David, Iuliana. "Road Traffic Safety Problem Based Learning Module." Thesis, Linköping University, Department of Science and Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-14691.
Abstract:
Road traffic safety has increasingly become in need of educated road safety professionals, as the number of accidents in the World Health Organization member countries exceeds one million. The profession itself is transitioning from experience based decision making to empirical, theoretical and mathematical based solutions. However, road traffic safety is a multidiscipline, crossing over many fields and requiring a high degree of communication between different institutions. There are very few institutions that provide programs in the field; furthermore, they employ traditional lecture-based teaching methods. The traditional teaching environment does not fulfill the educational needs of future traffic safety professionals due to its rigidity and lack of problem solving exercises.
An alternative method, namely problem based learning, is recommended as an alternative teaching method in this paper. The thesis is constructed in such a way as to develop a complete road traffic safety educational module at graduate and post graduate level.
The theoretical basis on which a road traffic safety module is later built is presented in the first part of the thesis. Major concepts in road traffic safety, as well as problem based learning methods are investigated. In addition, a literature review SWOT analysis based on literature is conducted.The module development consists of establishing the road traffic safety learning goals for each segment in the module, appropriate assessment criteria and group work format. The module contains gradual difficulty level problems, starting from the easiest topic and easiest format (closed ended problem) and ending with the hardest topic and hardest format (open ended problem).
The last section employs the SWOT analysis findings in the theoretical section to develop a SWOT analysis of the road traffic safety module presented in the thesis.
12
Nilsson, Philip, and Sebastian Nilsson. "Application of Poisson Regression on Traffic Safety." Thesis, KTH, Matematisk statistik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-168201.
Abstract:
This study presents a model that explains the traffic fatality by exploring the Poisson regression model using two types of explanatory variables – referred to as internal and external factors. Internal factors contain variables closely linked to traffic safety, such as speed limits and belt usage (Strandroth et al., 2012), whereas external factors comprise a set of variables that the Swedish Transport Administration cannot control, such as the economy and demographic change (Wiklund et al., 2012). The purpose of the study is to evaluate the impact that internal and external factors have on the traffic fatality. This is done by modeling the traffic fatality using internal factors and then assessing the contribution of adding external factors in the regression model with a forward variable selection strategy. This study uses Swedish traffic fatality data as monthly statistics. The main characteristics of the data are that fatalities have generally decreased with time. Also, the data is characterized by a long term cyclical pattern as well as a yearly cyclical pattern. For the purpose of modeling the impact of internal factors, a model inspired by Brüde (1995) has been adopted, using the variable time as the only explanatory variable. It is concluded that internal factors can be used to significantly explain the general trend of the development of traffic fatalities. The variables chosen to represent external factors were economic development, traffic exposure, demographic development and seasonal trend. The study concludes that the variables economic development, traffic exposure and demographic development significantly contribute to explain the long term cyclical trends, indicating that traffic fatality is a complex multivariate system where no single variable can solely explain its dynamics. The external factor seasonal trend has the most impact of the examined external factors and explains the yearly cyclical pattern by itself. The model presented in this study shows high explanatory power and overall good fit to fatality data, making it a promising tool for statistical analysis of factors contributing to fatality. Especially for the Swedish Transport Administration, the impact of external factors can be evaluated statistically. This study leaves room for further research to assess the impact of additional external factors as well as evaluating the model’s predictive power, both of interest to the Swedish Transport Administration.Denna studie presenterar en modell som förklarar dödsfall i trafiken genom tillämpning av Poissonregression där två typer av förklaringsvariabler använts – interna och externa faktorer. Interna faktorer innefattar variabler som är direkt knutna till trafiksäkerhet, såsom hastighetsbegränsningar och användande av säkerhetsbälte (Strandroth et al., 2012). Externa faktorer är variabler som Trafikverket inte kan kontrollera, såsom landets ekonomi och demografiska förändringar (Wiklund et al., 2012). Syftet med denna studie är att evaluera påverkan av interna och externa faktorer på dödsfall i vägtrafik. Detta görs genom att analysera hur väl interna faktorer förklarar dödsfall i vägtrafik och sedan undersöka förbättringen av att införa externa faktorer som förklaringsvariabler genom användande av en forward variable selection-strategi. Denna studie använder månatlig data över dödsfall i svensk trafik. Dessa data karaktäriseras av en nedgående trend. Dynamiken av dödsfall visar på ett långt cykliskt mönster samt ett kortare, årligt mönster. I syfte att modellera påverkan av interna faktorer har en modell inspirerad av Brüde (1995) tillämpats. Denna modell använder enbart variabeln tid som förklaringsvariabel. Studien konstaterar att interna faktorer kan användas för att signifikant beskriva en generell trend för utvecklingen av dödsfall i vägtrafik. Variablerna som har valts att representera externa faktorer är ekonomisk utveckling, trafikarbete, demografi samt en säsongstrend. Studien konstaterar att variablerna ekonomisk utveckling, trafikarbete och demografi beskriver det långa cykliska mönstret, vilket tyder på att dödsfall i vägtrafik är av komplex natur och kan inte beskrivas av en ensam variabel. Den externa faktorn säsongstrend förbättrar modellen mest av de externa faktorerna och kan ensam förklara det kortsiktiga cykliska mönstret. Den modell som presenteras i denna studie har hög förklaringsgrad och en överlag bra modellanpassning, vilket gör den till ett lovande verktyg för statistisk analys av faktorer bidragande till dödsfall i trafiken. Modellen är av särskilt intresse för Trafikverket då den tillåter statistisk utvärdering av externa faktorers påverkan. Denna studie lämnar utrymme för framtida forskning att utvärdera påverkan av ytterligare externa faktorer samt att evaluera modellens förmåga att prognostisera framtida antal dödsfall i vägtrafik, vilka båda är intresseområden för Trafikverket.
13
Jonsson, Patrik. "Intelligent networked sensors for increased traffic safety." Licentiate thesis, Mittuniversitetet, Institutionen för informationsteknologi och medier, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-14982.
Abstract:
Our society needs to continuously perform transports of people and goods toensure that business is kept going. Every disturbance in the transportation ofpeople or goods affects the commerce and may result in economical losses forcompanies and society. Severe traffic accidents cause personal tragedies forpeople involved as well as huge costs for the society. Therefore the roadauthorities continuously try to improve the traffic safety. Traffic safety may beimproved by reduced speeds, crash safe cars, tires with better road grip andimproved road maintenance. The environmental effects from roadmaintenance when spreading de-icing chemicals need to be considered, i.e.how much chemicals should be used to maximize traffic safety and minimizethe environmental effects. Knowledge about the current and upcoming roadcondition can improve the road maintenance and hence improve traffic safety.This thesis deals with sensors and models that give information about the roadcondition.The performance and reliability of existing surface mounted sensors wereexamined by laboratory experiments. Further research involved field studies tocollect data used to develop surface status models based on road weather dataand camera images. Field studies have also been performed to find best usageof non intrusive IR technology.The research presented here showed that no single sensor give enoughinformation by itself to safely describe the road condition. However, the resultsindicated that among the traditional road surface mounted sensors only theactive freezing point sensor gave reliable freezing point results. Furtherresearch aimed to find a model that could classify the road condition indifferent road classes from existing road weather sensor data and road images.The result was a model that accurately could distinguish between the roadconditions dry, wet, snowy and icy. These road conditions are clearly dissimilarand are therefore used as the definition of the road classes used in this thesis.Finally, results from research regarding remote sensing IR technology showedthat it significantly improves knowledge of the road temperature and statuscompared to data from surface mounted sensors.Vårt samhälle bygger på att det finns effektiva transporter av människor ochvaror för att säkerställa att samhällets funktioner fungerar och att företagenkan genomföra sina affärer. Störningar i transporterna av människor och varorpåverkar handeln och kan leda till ekonomiska förluster för både företag ochvårt samhälle. Allvarliga trafikolyckor orsakar personliga tragedier för deinblandade samt stora kostnader för samhället. Det är med denna bakgrundsom vägmyndigheterna kontinuerligt arbetar med att förbättratrafiksäkerheten. Trafiksäkerheten kan förbättras genom att minskahastigheterna, se till att bilarna blir krocksäkra, krav på däck med bättreväggrepp och ett bättre vägunderhåll. Miljöeffekterna från vinterväghållningdär avisningsmedel sprids på vägarna måste beaktas, d.v.s. hur mycketkemikalier bör användas för att maximera trafiksäkerheten och minimeramiljöpåverkan. Denna avhandling handlar om sensorer och modeller som gerinformation om väglaget. En kunskap om aktuellt och kommande väglag kanförbättra väghållningen och därmed öka trafiksäkerheten.I avhandlingen har prestanda och tillförlitlighet hos befintliga vägmonteradesensorer granskats i laboratorieexperiment. Data från fältstudier har använtsför att utveckla modeller som kan ge information om vägytans status baseratpå meteorologiska mätdata och kamerabilder. Det har också genomförtsfältstudier för att utforska den fördelaktigaste användningen av beröringsfriinfraröd sensorteknik.Den forskning som presenteras här visar att ingen enskild givare ger tillräckliginformation för att säkert beskriva väglaget. Från de traditionella ytmonteradesensorerna drogs slutsatsen att den aktiva fryspunktsgivaren gav de mesttillförlitliga fryspunktsresultaten. Det vidare arbetet handlade om att hitta enmodell som skulle kunna klassificera vägförhållanden i olika vägklassergenom att utnyttja information från befintliga sensorer och kamerabilder.Detta arbete resulterade i en modell som tillförlitligt kan särskilja väglagentorr, våt, snöig och isig. Dessa väglag är väsentligt olika och har därför valtssom väglagsklasser i denna avhandling. Under en säsong genomfördes ävenfältförsök med beröringsfri infraröd mätteknik där det visade sig att denberöringsfria teknologin förbättrar kunskapen om vägbanans temperatur och vägbanans status.
14
Andrade, Gustavo Riente de. "Relationship between traffic operations and road safety." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18144/tde-23012019-011508/.
Abstract:
Since before the release of the Highway Safety Manual research has been indicating the need to incorporate mobility and control aspects to road safety analysis. The first part of this work developed and implement in an existing computational engine a signal timing optimization method that considers mobility, safety, and emissions measures simultaneously. A sensitivity analysis was conducted to provide insight on the practical effects and order of relevance of 20 key input variables. Mobility improvement performance usually coincides with emissions improvements, but sometimes at the expense of safety. The second part of this work investigated the relationship between hourly traffic density and crash rates on Brazilian expressways with different characteristics, based on a database containing over 20,000 crashes and more than 35 million traffic volume observations and. The resulting curves for urban expressways follow a U shape, with minimum values associated with LOS B to C, while the relationships for rural expressways were found to be continuously increasing, suggesting that low volume rural roads are safer than the higher volume ones. The analysis of other influencing factors revealed that nighttime conditions, weaving segments and urban multilane highways could be related to higher crash rates. The third part of the project extends the analysis to crash severity modeling, using an ordered response choice model. The framework that better fit this database led to the development of two different models: single-vehicle crashes (SV) and multiple-vehicle crashes (MV), since the factors that explain the severity of crashes varies widely between these models. For instance, guardrails and barriers proved to effectively reduce severity for SV crashes, for which run-offs are the most severe crash type. The unique database used in this study also allowed for an investigation of the influence of prevailing traffic conditions on crash severity, while still controlling for all other factors. The results suggested that multiple-vehicle crash severity is negatively related with traffic density, while single-vehicle crashes are more closely related to speed. The findings of this work have implications to policy and design decisions, and the produced equation could be incorporated to active traffic management (ATM) and HCM reliability analysis.Desde antes da publicação do Highway Safety Manual, vários pesquisadores indicam a necessidade de se incorporar aspectos de operação de tráfego à análise de segurança viária. A primeira parte deste trabalho desenvolveu e implementou em uma ferramenta computacional existente um método de otimização de tempos semafóricos que considera medidas de desempenho de operação, segurança e emissões simultaneamente. Uma análise de sensibilidade foi realizada para produzir conhecimento sobre os efeitos práticos e a ordem de relevância de 20 variáveis de entrada principais. O desempenho da programação semafórica em termos de redução dos atrasos geralmente coincide com redução das emissões, embora às vezes às custas da segurança. A segunda parte deste trabalho investigou a relação entre a densidade horária de tráfego e as taxas de acidentes em autoestradas e rodovias de pista dupla brasileiras com características diversas, com base em um banco de dados contendo mais de 20.000 registros de acidentes e mais de 35 milhões de observações de tráfego. As curvas resultantes para rodovias urbanas seguem um formato em U, com valores mínimos associados aos níveis de serviço B a C, enquanto que as relações para as rodovias rurais são contínuas e crescentes, sugerindo que rodovias rurais de baixo volume são mais seguras do que as de maior volume. A análise de outros fatores revelou que condições noturnas, segmentos de entrelaçamento e rodovias de pista dupla convencionais urbanas estariam relacionadas a maiores taxas de acidentes. A terceira parte deste projeto amplia a análise para modelagem de severidade dos acidentes, usando um modelo de escolha discreta ordenado. A estrutura que melhor se adequa a esse banco de dados levou ao desenvolvimento de dois modelos diferentes: acidentes com um veículo e acidentes com múltiplos veículos, já que os fatores que explicam a severidade dos acidentes variam muito entre esses modelos. Por exemplo, defensas e barreiras se mostraram efetivas para a redução da severidade de acidentes com um veículo, para as quais a saída de pista é o tipo de acidente mais grave. O amplo banco de dados usado neste estudo também permitiu uma investigação da influência das condições de tráfego na severidade do acidente, em comparação com todos os outros fatores. Os resultados sugeriram que a severidade de acidentes de múltiplos veículos está negativamente relacionada com a densidade de tráfego, enquanto colisões com um único veículo estão mais relacionadas à velocidade. As descobertas deste trabalho têm implicações nas decisões sobre políticas e projetos de transportes, e a equação produzida pode ser incorporada à análise de confiabilidade do gerenciamento ativo do tráfego (ATM) e do Highway Capacity Manual.
15
Aslansefat, K., Sohag Kabir, Amr R. A. Abdullatif, Vinod Vasudevan, and Y. Papadopoulos. "Toward Improving Confidence in Autonomous Vehicle Software: A Study on Traffic Sign Recognition Systems." IEEE, 2021. http://hdl.handle.net/10454/18591.
Abstract:
YesThis article proposes an approach named SafeML II, which applies empirical cumulative distribution function-based statistical distance measures in a designed human-in-the loop procedure to ensure the safety of machine learning-based classifiers in autonomous vehicle software. The application of artificial intelligence (AI) and data-driven decision-making systems in autonomous vehicles is growing rapidly. As autonomous vehicles operate in dynamic environments, the risk that they can face an unknown observation is relatively high due to insufficient training data, distributional shift, or cyber-security attack. Thus, AI-based algorithms should make dependable decisions to improve their interpretation of the environment, lower the risk of autonomous driving, and avoid catastrophic accidents. This paper proposes an approach named SafeML II, which applies empirical cumulative distribution function (ECDF)-based statistical distance measures in a designed human-in-the-loop procedure to ensure the safety of machine learning-based classifiers in autonomous vehicle software. The approach is model-agnostic and it can cover various machine learning and deep learning classifiers. The German Traffic Sign Recognition Benchmark (GTSRB) is used to illustrate the capabilities of the proposed approach.
This work was supported by the Secure and Safe MultiRobot Systems (SESAME) H2020 Project under Grant Agreement 101017258.
16
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.
Abstract:
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.
17
Nihlén, Fahlquist Jessica. "Moral responsibility in traffic safety and public health." Licentiate thesis, KTH, Philosophy and History of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-609.
18
Chimba, Deo. "Traffic Concurrency Management Through Delay and Safety Mitigations." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/73.
Abstract:
Travelers experience different transportation-related problems on roadways ranging from congestion, delay, and crashes, which are partially due to growing background traffic and traffic generated by new developments. With regards to congestion, metropolitan planning organizations (MPOs) pursue a variety of plans for mitigating congestion. These plans include, amongst other measures, imposing impact fees. The current research evaluates how delay and safety can be incorporated in the mitigation process as special impact fees. This study also evaluates traffic projection methodologies used in traffic impact studies. Traffic volume is a critical factor in determining both current and future desired and undesired highway operations. Highway crashes are also influenced by traffic volume, as a higher frequency of crashes is expected at more congested locations and vice versa. Accurately forecasted traffic data is required for accurate future planning, traffic operations, safety evaluation, and countermeasures. Adhering to the importance of accurate traffic projection, this study introduces a simplistic traffic projection methodology for small-scale projection utilizing three parameters logistic function as a forecasting tool. Three parameters logistic function produced more accurate future traffic prediction compared to other functions. When validation studies were performed, the coefficient of correlation was found to be above 90 percent in each location. The t-values for the three parameters were highly significant in the projection. The confidence intervals have been calculated at a 95 percent confidence level using the delta method to address the uncertainty and reliability factor in the projection using logistic function. A delay mitigation fee resulting from increases in travel time is also analyzed in this research. In regular traffic flow, posted speed limit is the base of measuring travel time within the segment of the road. The economic concept of congestion pricing is used to evaluate the impact of this travel time delay per unit trip. If the relationship between the increase in time and trip is known, then the developer can be charged for the costs of time delays for travelers by using that relationship. The congestion pricing approach determines the average and marginal effect of the travel time. With the known values of time, vehicle occupancy, and number of travel days per year, the extra cost per trip caused by additional trips is estimated. This cost becomes part of the mitigation fee that the developer incurs as a result of travel time delays for the travelers due to the development project. Using the Bureau of Public Road (BPR) travel time function and parameters found in 2000 HCM (Highway Capacity Manual), the average and marginal travel times were determined. The value of time was taken as $7.50 per hour after reviewing different publications, which relate it to minimum wage. The vehicle occupancy is assumed as 1.2 persons per vehicle. Other assumptions include 261 working days per year and 4 percent rate of return. The total delay impact fee will depend on the number of years needed for the development to have effect. Since the developer is charged a road impact fee due to constructions cost for the road improvement, the delay mitigation fee should be credited to the road impact fee to avoid double charging the developer. As an approach to incorporate safety into mitigation fees, the study developed a crash prediction model in which all factors significantly influencing crash occurrences are considered and modeled. Negative binomial (NB) is selected as the best crash modeling distribution among other generalized linear models. The developed safety component of the mitigation fee equation considers scenarios in which the proposed new development is expected to increase crash frequency. The mitigation fee equation is designed to incorporate some roadway features and traffic characteristics generated by the new development that influence crash occurrence. Crash reduction factors are introduced and incorporated in the safety mitigation fees equation. The difference between crash frequency before and after the development is multiplied by the crash cost then divided by the trips to obtain crash cost per trip. Crash cost is taken as $28,000/crash based on literature review. To avoid double charging the developer, either the road impact fee is applied as a credit to the delay mitigation fee or vice versa. In summary, this study achieved and contributed the following to researchers and practitioners: ... Developed logistic function as a simplified approach for traffic projection ... Developed crash model for crash prediction ... Developed safety mitigation fee equation utilizing the crash modeling ... Developed delay mitigation fee equation using congestion pricing approach
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Nihlén, Fahlquist Jessica. "Moral responsibility and the ethics of traffic safety." Doctoral thesis, KTH, Filosofi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4670.
Abstract:
The general aim of this thesis is to present and analyse traffic safety from an ethical perspective and to explore some conceptual and normative aspects of moral responsibility. Paper I presents eight ethical problem areas that should be further analysed in relation to traffic safety. Paper II is focused on the question of who is responsible for traffic safety, taking the distribution of responsibility adopted through the Swedish policy called Vision Zero as its starting point. It is argued that a distinction should be made between backwardlooking and forward-looking responsibility and that Vision Zero should be understood in terms of this distinction. Paper III discusses responsibility ascriptions in relation to public health problems like obesity and lung cancer. It is argued that what makes discussions about who is responsible for such problems complicated is that we have two aims when ascribing responsibility to someone. First, we want responsibility ascriptions to be fair and morally justified. Second, we also want to achieve progress and solve problems through ascribing responsibility to someone. It is argued that the two aims influence debates concerning who is responsible for problems like obesity and lung cancer and that we should attempt at striking a balance that is both perceived as fair and that is efficient. Paper IV discusses two potential arguments against the suggestion that alcohol interlocks should be mandatory in all cars, namely 1) that it displaces the responsibility of individual drivers, and 2) that it constitutes a paternalistic interference with drivers. The first objection is found unconvincing, while the second only has limited bite and may be neutralized if paternalism is accepted for the sake of greater net liberty. It is argued that if technological development can make mandatory interlocks cost-efficient, the policy seems a commendable public health measure. In Paper V, the question discussed is to what extent individuals should be ascribed moral responsibility for the environmentally damaging consequences of their actions. It is argued that responsibility depends on the reasonableness of the alternatives open to an individual when acting. The lack of reasonable alternatives should reduce the degree of individual responsibility.QC 20100831
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Nihlén, Fahlquist Jessica. "Moral responsibility in traffic safety and public health /." Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-609.
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Chisalita, Ioan. "Communication and Networking Techniques for Traffic Safety Systems." Doctoral thesis, Linköping : Department of Computer and Information Science, Linköpings universitet, 2006. http://www.bibl.liu.se/liupubl/disp/disp2006/tek1018s.pdf.
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Dully, Michael. "Traffic Safety Evaluation of Future Road Lighting Systems." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-101978.
Abstract:
While new road lighting technologies, either LED or adaptive road lighting systems, offer a wide range of unique potential benefits (mainly in terms of energy savings), it is necessary to evaluate the safety impacts of these technologies on road users. The literature survey shows that providing light on previous unlit roads has a positive effect on traffic safety. Reducing the amount of light has the opposite effect. These studies are usually conducted by using crash numbers, which makes it impossible to draw conclusions on changes in driving behaviour. Driving behaviour analyses need special approaches and indicators. Therefore indirect indicators such as speed and safety relationship, jerky driving and traffic conflict parameters are presented. The individual character of such data is difficult to deal with and limits big scale analyses. In order to have a practical example of such indicators a case study is conducted. Floating car data collected in Vienna is used to analyse travel speeds of taxi drivers at two LED test sites. A simple before-after analysis is used with data from January 2011 to May 2012 in order to examine an expected increase in speed due to a better visual performance of LED light. However the results show either no changes at all or a trend in speed reduction of 1km/h in average. Unfavourable test site locations might limit the significance of the results.
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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.
Abstract:
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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Wang, Michael. "Traffic Modeling and Safety Analysis on Motorway Ramps." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/376817.
Abstract:
The whole research program aimed to improve operation, sustainability and safety of ramp areas. For this purpose, I first calculated passenger car equivalents (PCE) for a specific type of heavy vehicles (HVs) on the on-ramp through various different PCE methods. Through this study, I concluded that 1) homogenization based method (HM) cannot properly predict the variation trend of PCE values over traffic volume due to the low sensitivity of the speed to the change in traffic volume; 2) both time headway based method (THM) and traffic flow based method (TFM) can derive the results which are relatively consistent with outcome from simulation model. As this study is not relevant with the overall aim of the research program, it will be presented in Appendix 1.
The areas adjacent to ramps have always been regarded as traffic bottlenecks during peak hours because the frequent interactions between the merging and diverging traffic and the through traffic contribute to the loss in travel time. Currently, there is few literature to explore the impact of on-ramp lane configurations on travel time of through traffic. In this study, I comparatively analyzed the impact of freeway mainline traffic flow and proportion of mainline heavy goods vehicles (HGVs) on the average travel time of the road segment fitted with two types of on-ramp lane arrangements. The mainline traffic volumes vary from 800 to 2200 and the proportions of mainline HGVs range from 0 to 12%. The calibrated and validated simulation models were used to generate the average travel time under different traffic scenarios. Through comparative analyses, the following conclusions can be drawn. 1) For the impact of HGVs on travel time, when the mainline traffic flow is below 1200 vehs/hr/ln, the performance in travel time of the road segment fitted with zip merging outperforms that fitted with added lane; when the mainline traffic volume is 1400 vehs/hr/ln, through traffic, starting from 10% of HGVs, spends less travel time on the road segment equipped with added lane; when the mainline traffic flow reaches 2200 vehs/hr/ln, the road segment fitted with added lane roundly performs better than that fitted with zip merging in term of travel time. 2) For the impact of traffic volume on travel time, although the proportion of mainline HGVs is 0, the road segment equipped with added lane starts to outperform that equipped with zip merging when traffic flow is approximately 2200 vehs/hr/ln; when the proportion of mainline HGVs is 12%, through traffic spends less travel time on the road segment fitted with added lane once the mainline traffic flow exceeds 1200 vehs/hr/ln. The abovementioned conclusions come from a case study. Currently, I cannot ensure they apply to other closely spaced on- and off-ramp areas. Further study will be conducted in future works.
As traffic operation has a close connection with environmental sustainability, the assessment of carbon dioxide emissions (CO2) was also the key point of the research program. Areas adjacent to ramps have been viewed as zones with high emissions due to more traffic stops. Currently, many researchers have deemed that proper traffic control and the improvements in geometry can reduce CO2 emissions in such areas. Few research have assessed the impact of on-ramp lane configurations on sustainability. In this study, I used the improved comprehensive modal emissions model (CMEM) to quantitatively evaluate the impact of mainline traffic volume and percentages of mainline HGVs on CO2 emitted on the road segment fitted with two on-ramp lane arrangements. Traffic volumes range from 800 to 1800 vehs/hr/ln with an increment of 200 vehs/hr/ln and the proportions of HGVs vary from 2% to 10% with an increment of 2%. The results show that 1) For the impact of HGVs on CO2 emissions, when traffic flow is 800 vehs/hr/ln, through traffic on the road segment fitted with added lane can obtain a better performance in CO2 emissions after the percentage of mainline HGVs exceeds 8%; when traffic flow varies from 1000 to 1800 vehs/hr/ln, through traffic generates less CO2 emissions on the road segment equipped with added lane under the effect of any percentage of HGVs; 2) For the impact of traffic volume on CO2 emissions, when the proportion of HGVs is 2%, less CO2 is emitted on the road segment fitted with added lane after mainline traffic flow reaches 1000 vehs/hr/ln; when the proportion of HGVs reaches 10%, the performance of added lane on CO2 emissions is completely superior to that of zip merging. In addition, two-factor-based CO2 emissions contour charts were depicted. They could assist traffic engineers in selecting an appropriate combination of traffic volume and percentage of HGVs in order to achieve control of emissions.
The poor performance in traffic operation may contribute to more traffic conflicts. My research direction thus turned to safety assessment for on-ramps. Nowadays, many crash surrogate metrics have been proposed and designed for predicting the rear-end crash risks for basic freeway sections, including the time to collision (TTC), the deceleration rate to avoid crash (DRAC), the crash potential index (CPI) and the aggregated crash index (ACI). However, they might not be applicable to assess crash risks for on-ramps. As a consequence, I proposed the simplified crash surrogate metric (SCSM) to predict the rear-end crash risks for on-ramps. A one-lane on-ramp of Pacific Motorway, Australia was selected to validate the proposed surrogate metric. Another two surrogate measures (TTC and ACI) were compared with the SCSM through a simple proportional relationship between the societal risk index and crash rates. Through this study, I conclude that 1) as an upgraded version of the TTC, the SCSM not only features the same straightforward closed form as the traditional TTC, but also makes up for the shortcoming of the TTC that is unable to accurately assess crash risks in saturated traffic flow; 2) the TTC based surrogate metric performed the worst; 3) the performance of the SCSM is more or less similar to that of the ACI. But considering the ability to resolve practical engineering issues, the SCSM is superior to the ACI.
Hotspots identification (HSID), a reactive crash prediction based on the historical crash counts, is crucial to transport authorities for evaluating the risk level of the object road sites. Many researchers have focused on improving the accuracy of HSID, namely to identify those un-identified hotspots that should have been treated. In practice, several conventional HSID approaches have been developed and applied for decades, but they fail to take the daily variability of traffic flow and crash record into account. To address it, four novel Empirical Bayesian (EB) based methods (for (1) morning and (2) afternoon peak hours, and (3) daytime and (4) night off-peak hours) were proposed to screen hotspots in the Pacific Motorway Southeast Queensland section linking Brisbane to Gold Coast. The detailed six-year crash records were used. I further analyzed the applicability of four proposed EB-based methods and three traditional HSID methods: (5) crash frequency method (CFM), (6) societal risk-based method (SRCM), and (7) Empirical Bayesian method (EB) in regard to freeway main carriageways, on-ramps and off-ramps through two consistency tests. Through this study, the following conclusions were drawn. 1) The EB-based methods considering the effect of daily variability outperform other approaches in the HSID for freeway main carriageways. 2) The performances in proposed methods are inferior to those in the EB and the CFM in the HSID for on- and off-ramps. 3) The conventional EB method possess the best performance in the HSID for on- and off-ramps.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
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Rusli, Rusdi Bin. "Traffic safety along rural mountainous highways in Malaysia." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/113718/2/Rusdi_Bin_Rusli_Thesis.pdf.
Abstract:
This research has generated an in-depth understanding of road traffic crashes along rural mountainous highways in Sabah, Malaysia that will enable development of targeted countermeasures. To achieve this, an extensive set of road traffic data was collected through field surveys and secondary sources, and a set of cutting-edge statistical and economic models were developed to investigate (i) single-vehicle crashes, (ii) multi-vehicle crashes, and (iii) injury severity of traffic crashes along rural mountainous highways. Findings from this research will contribute to the design of a safer environment along rural mountainous highways, which are common in many developing countries.
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Chee, Wing-yan David. "Road accidents : identification of patterns and trends /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21128819.
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Shankar, Venkataraman N. "Limited dependent variable and structural equations models : empirical applications to traffic operations and safety /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/10179.
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Sze, Nang-ngai. "Quantitative analyses for the evaluation of traffic safety and operations." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39707398.
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Cheung, Wai-sin. "Road safety problems in China the rural-urban divide /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B4154822X.
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Talbot, Nerida L. "Don't drive angry : the development and validation of an Australian measure of road rage /." [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16832.pdf.
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Arun, Ashutosh. "A novel Road User Safety Field Theory for traffic safety assessment applying video analytics." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/234039/1/Ashutosh_Arun_Thesis.pdf.
Abstract:
This thesis introduces a new Road User Safety Field Theory to proactively assess traffic safety by studying the interactions of various road users at signalised intersections. The proposed theory combines road traffic environmental factors, vehicle capabilities and personal characteristics to determine the extent and strength of road users’ safety ‘bubble’ or field across various traffic interactions. By applying the Artificial Intelligence-based video data analytics, the proposed Road User Safety Field Theory is found to better estimate crash risks in terms of crash frequency and severity than traditional traffic conflict techniques.
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Kalus, Falk. "Risk homeostasis reconsidered the limits of traffic safety regulation /." Doctoral thesis, [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963887033.
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Siddiqui, Chowdhury. "Macroscopic Traffic Safety Analysis Based on Trip Generation Characteristics." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3385.
Abstract:
Recent research has shown that incorporating roadway safety in transportation planning has been considered one of the active approaches to improve safety. Aggregate level analysis for predicting crash frequencies had been contemplated to be an important step in this process. As seen from the previous studies various categories of predictors at macro level (census blocks, traffic analysis zones, census tracts, wards, counties and states) have been exhausted to find appropriate correlation with crashes. This study contributes to this ongoing macro level road safety research by investigating various trip productions and attractions along with roadway characteristics within traffic analysis zones (TAZs) of four counties in the state of Florida. Crashes occurring in one thousand three hundred and forty-nine TAZs in Hillsborough, Citrus, Pasco, and Hernando counties during the years 2005 and 2006 were examined in this study. Selected counties were representative from both urban and rural environments. To understand the prevalence of various trip attraction and production rates per TAZ the Euclidian distances between the centroid of a TAZ containing a particular crash and the centroid of the ZIP area containing the at fault driver's home address for that particular crash was calculated. It was found that almost all crashes in Hernando and Citrus County for the years 2005-2006 took place in about 27 miles radius centering at the at-fault drivers' home. Also about sixty-two percent of crashes occurred approximately at a distance of between 2 and 10 miles from the homes of drivers who were at fault in those crashes. These results gave an indication that home based trips may be more associated with crashes and later trip related model estimates which were found significant at 95% confidence level complied with this hypothesized idea. Previous aggregate level road safety studies widely addressed negative binomial distribution of crashes. Properties like non-negative integer counts, non-normal distribution, over-dispersion in the data have increased suitability of applying the negative binomial technique and has been selected to build crash prediction models in this research. Four response variables which were aggregated at TAZ-level were total number of crashes, severe (fatal and severe injury) crashes, total crashes during peak hours, and pedestrian and bicycle related crashes. For each response separate models were estimated using four different sets of predictors which are i) various trip variables, ii) total trip production and total trip attraction, iii) road characteristics, and iv) finally considering all predictors into the model. It was found that the total crash model and peak hour crash model were best estimated by the total trip productions and total trip attractions. On the basis of log-likelihoods, deviance value/degree of freedom, and Pearson Chi-square value/degree of freedom, the severe crash model was best fit by the trip related variables only and pedestrian and bicycle related crash model was best fit by the road related variables only. The significant trip related variables in the severe crash models were home-based work attractions, home-based shop attractions, light truck productions, heavy truck productions, and external-internal attractions. Only two variables- sum of roadway segment lengths with 35 mph speed limit and number of intersections per TAZ were found significant for pedestrian and bicycle related crash model developed using road characteristics only. The 1349 TAZs were grouped into three different clusters based on the quartile distribution of the trip generations and were termed as less-tripped, moderately-tripped, and highly-tripped TAZs. It was hypothesized that separate models developed for these clusters would provide a better fit as the clustering process increases the homogeneity within a cluster. The cluster models were re-run using the significant predictors attained from the joint models and were compared with the previous sets of models. However, the differences in the model fits (in terms of Alkaike's Information Criterion values) were not significant. This study points to different approaches when predicting crashes at the zonal level. This research is thought to add to the literature on macro level crash modeling research by considering various trip related data into account as previous studies in zone level safety have not explicitly considered trip data as explanatory covariates.M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering MS
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Thorslund, Birgitta. "Effects of hearing loss on traffic safety and mobility." Doctoral thesis, Linköpings universitet, Institutionen för beteendevetenskap och lärande, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-111933.
Abstract:
The aim of this PhD thesis was to investigate traffic safety and mobility for individuals with hearing loss (HL). Three studies were conducted: 1. a questionnaire survey aimed to evaluate differences in choice of transportation that might be related to HL, 2. a driving simulator study that looked into compensatory strategies and evaluated the efficiency of a tactile signal to alert the driver, and 3. a field study to evaluate these effects in real traffic and to evaluate a navigation system with a supportive tactile signal. The effects of HL discovered in this thesis add to the knowledge and understanding of the influence of HL on traffic safety and mobility. Differences found consistently point to a generally more cautious behavior. Compensatory and coping strategies associated with HL are bound to driving complexity and appear when complexity increases. These strategies include driving at lower speeds, using a more comprehensive visual search behavior and being less engaged in distracting activities. Evaluation of a tactile signal showed that by adding a tactile modality, some driver assistance systems can also be made accessible to drivers with HL. At the same time, the systems might be more effective for all users, since the driver can be more focused on the road. Based on the results in this thesis, drivers with HL cannot be considered an increased traffic safety risk, and there should be no need for adjustments of the requirements of hearing for a license to drive a car.Syftet med den här doktorsavhandlingen var att undersöka trafiksäkerhet och mobilitet för individer med hörselnedsättning (HN). Tre studier har genomförts: 1. en enkätstudie för att undersöka skillnader i transportvanor relaterade till HN, 2. en körsimulatorstudie for att titta på kompensatoriska strategier och utvärdera effektiviteten i en taktil signal för att påkalla förarens uppmärksamhet och 3. en fältstudie för att undersöka effekterna i riktig trafik samt utvärdera ett navigationssystem med en taktil signal som stöd för navigering. Effekterna av HN som kom fram i denna avhandling bidrar till kunskapen och förståelsen för hur HN påverkar trafiksäkerhet och mobilitet. De funna skillnaderna pekar konsistent mot ett generelltmera försiktigt beteende. Kompensatoriska - och copingstrategier förknippade med HN beror på körkomplexitet och observeras när komplexiteten ökar. Dessa strategier innebär körning med lägre hastighet, mera heltäckande visuell avsökning och mindre engagemang i distraherande uppgifter. Utvärdering av en taktil signal visade att genom att lägga till en taktil modalitet kan vissa förarstödsystem bli tillgängliga även för förare med HN. Samtidigt kan systemen bli mera effektiva för alla användare eftersom föraren då kan fokusera mera på vägen. Baserat på resultaten i den här avhandlingen kan inte förare med HN betraktas som någon förhöjd risk och det bör därmed inte finnas något behov av att justera hörselkraven när det gäller körkortsinnehav.
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Das, Subasish. "Effectiveness of Inexpensive Crash Countermeasures to Improve Traffic Safety." Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10002395.
Abstract:
Highway safely improvement is a critical issue for local and national transportation authorities. One of the most important tasks in highway safety analysis is the identification of appropriate countermeasures that might be useful in making signicant safety improvement. Targeting safety at roadway segments has been the key focus of safety related projects at all levels. Recognizing that resources are limited in Louisiana, an emphasis is provided on the identication of strategies that will yield impressive results that are easily implemented from both time and cost perspective. An extensive study on the selection of Louisiana specific inexpensive and effective countermeasures has not been performed yet. Safety countermeasures with high safety effects and low implementation costs are always preferable. This dissertation has developed a Six Sigma DMADV tool uniquely designed for determining effective, inexpensive countermeasures that can be used in both aggregate and disaggregate level. Using the framework of DMADV toolset, this dissertation has selected three inexpensive countermeasures suitable for Louisiana and has developed CMFs for the selected countermeasures. Moreover, a commercialization tool has been developed for transferring the research results to successful commercial product design. The results from this dissertation are practice-ready and has been used by the transportation authorities in Louisiana.
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Reddy, Nitin. "DRIVER ASSISTANCE FOR ENHANCED ROAD SAFETY AND TRAFFIC MANAGEMENT." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1237493386.
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Gladhill, Kristie Werner. "Exploring Traffic Safety and Urban Form in Portland, Oregon." PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/86.
Abstract:
Street layout and design, once established, are then not easily changed. Urban form affects community development, livability, sustainability, and traffic safety. There has been an assumed relationship between urban form and traffic safety that favors designs with less through streets to improve safety. An empirical study to test this assumed relationship was carried out for crash data for Portland, Oregon. This thesis presents an empirical methodology for analyzing the relationship between urban form and traffic safety utilizing a uniform grid for the spatial unit. Crashes in the Portland, Oregon city limits from 2005-2007 were analyzed and modeled using negative binomial regression to study the effect of urban form and street layout through factors on exposure, connectivity, transit accessibility, demographic factors, and origins and destinations. These relationships were modeled separately by mode: vehicle crashes, pedestrian and bicycle crashes. Models were also developed separately by crash type and by crash injury severity. The models found that urban form factors of street connectivity and intersection density were not significant at 95% confidence for vehicle and pedestrian crash rates, nor for different crash severity levels, indicating that high connectivity grid street layout may have comparable safety to loops and lollipops, in contrast to results in earlier studies. Elasticity for all models was dominated by VMT increases. Business density, population and transit stops were also significant factors in many models, underlining the importance not only of street layout design, but also planning to direct development to influence where businesses, employment, and housing will grow and handle traffic volumes safely.
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Thomas, Chester. "Georgia intersection safety improvement program." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24620.
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Al-Senan, Shukri Hasan. "A study of head-on crash sites." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/21466.
40
Vap, Derek. "Safety evaluation of large truck-passenger vehicle interactions and synthesis of safety corridors." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4917.
Abstract:
Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 4, 2008) Includes bibliographical references.
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張煒倩 and Wai-sin Cheung. "Road safety problems in China: the rural-urban divide." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B4154822X.
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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.
Abstract:
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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Kittelson, Matthew James. "The economic impact of traffic crashes." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34804.
Abstract:
The purpose of this thesis is to quantify the economic costs associated with traffic crashes for 83 of the largest metropolitan areas in the United States and compare those costs to that of congestion. This was done by collecting injury and fatality data for each area and multiplying those by economic cost estimates for each developed by the FHWA. The findings of this analysis show that the economic cost of traffic crashes exceeds the economic costs of congestion in every metropolitan area studied. These results indicate that transportation safety deserves similar consideration to that of traffic congestion when allocation transportation funds.
44
Yang, Chun-Ming. "Enhancing driving safety through proper message design on variable message signs /." View online ; access limited to URI, 2005. http://0-wwwlib.umi.com.helin.uri.edu/dissertations/dlnow/3206259.
45
Park, Jin-Soo. "Marine traffic engineering in Korean coastal waters." Thesis, University of Plymouth, 1994. http://hdl.handle.net/10026.1/2410.
Abstract:
This study describes and discusses the marine casualties, the effectiveness of existing traffic services, and marine safety and Vessel Traffic Service(VTS) in Korean coastal waters. Marine traffic is comprehensively assessed in Korean waters, an analysis of casualties is undertaken by block scheme. Marine environmental parameters are identified relating to marine casualties as appropriate. Various statistical techniques are employed to evaluate the inter-relationships between individual causal factors, and for the first time effect level is instituted to quantify the relative importance of the causal factors in Korean waters. A further innovation is the examination of the adequacy of existing Korean traffic services by casualty and traffic analysis, and an accident danger index is introduced to compare accident danger over different .time periods. A mixed population of contributors to marine safety is sought by questionnaire. The design of this is both innovative and original in content in order to evaluate the perceived importance of the various risk factors, the marginal effectiveness of various options in reducing risks, and their weight with regard to YTS services and activities, the main part of the study uses an original multiple coefficient to estimate casualty reduction rate and a new method to quantify the effectiveness of VTS. The Korean waters traffic study is conducted as an intermediate level and provides the data base for the main body of work. The conclusions include recommendations with respect to the stricter enforcement of the routeing scheme(TSS) and the adoption of further traffic observation/surveillance over the areas concerned. Finally it is noted in particular that additional Vessel Traffic Service and Traffic Separation Schemes are now required if any substantial improvement is to be achieved in marine traffic safety in Korean coastal waters.
46
Liu, Yan. "Highway Capacity and Traffic Behavior under Connected and Automated Traffic Environment." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627667986751621.
47
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.
Abstract:
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.
48
Wanvik, Per Ole. "Road Lighting and Traffic Safety : Do we need Road Lighting?" Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bygg, anlegg og transport, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-5396.
Abstract:
Road lighting is widely recognised as an efficient traffic safety measure. However, we know too little about the effect of road lighting on accidents in a given situation and we do not know what kind of lighting that is optimal for the situation. Society today has a demand for energy savings, locally and globally, and we should not use more energy for road lighting than is necessary. In the field of road lighting the demand for energy savings is accompanied by a fast development of techniques and equipment that give great opportunities for energy savings. The opportunity already exists to adapt the lighting to the actual road, traffic and weather situation. It is a problem, however, that we do not know what lighting quantity and quality which gives the best benefit – cost ratio. The objective of this thesis is to contribute to more knowledge about the relationship between road lighting and traffic safety and thus make a basis for benefit – cost calculations (including environmental costs). The thesis is based on four studies about the safety effect of road lighting, reported in four papers. The first is a literature study, the second is a Norwegian before-and-after study, the third is a cross-section study of Dutch accidents and the fourth is a study of Dutch motorway accidents. The thesis also contains three appendices presenting some more details from the studies than were shown in the papers. The content of the four papers are presented and discussed as a whole in a (fairly comprehensive) introductory part consisting of 10 chapters, where conclusions about the safety effect are discussed and summarised. The thesis in addition discusses the benefit – cost ratio of road lighting, but it is not treated in any of the papers. It has been useful to discuss this matter in advance of the discussion of the future role of road lighting. In the literature study (Paper I), the mean effect of road lighting on injury accidents during darkness was found to be -30 %. The mean effect on fatal accidents was -60 %. The mean effect on pedestrian injury accidents was -45 %, and on motorways the mean effect on injury accidents was -50 %. In the Norwegian before-and-after study (Paper II), the estimated effect of road lighting on injury accidents during darkness was -28 %. The estimated effect was larger at high speed limits than at low speed limits. The estimated effect was smaller on roads with AADT (average daily traffic volume) > 8000 vehicles than on roads with AADT < 8000 vehicles. In the cross-section study of accidents on all Dutch roads (Paper III), the mean effect of road lighting on injury accidents during darkness was found to be -50 %, while it was -54 % when only rural roads were considered. The effect on pedestrian, bicycle and moped accidents was larger than the effect on automobile and motorcycle accidents, and the differences were statistically significant. There was no significant difference between the safety effects for different accident types (Rear end collisions, Frontal collisions etc.) and no significant difference between the driver age groups 60 – 74 years and 30 – 39 years. The effect on fatal accidents was found to be slightly larger than the effect on injury accidents. The mean effect on twilight accidents was 2/3 of the effect during darkness. In the study of motorway accidents (Paper IV), the effect on injury accidents during darkness was found to be -49 % on Dutch motorways, while the effect seemed to be much smaller on British and Swedish motorways. On Dutch rural roads and Dutch motorways, the estimated effect of road lighting on accidents during darkness was smaller during adverse weather and road surface conditions than in fine weather and dry surface conditions. The differences were statistically significant. In fog, there was found no effect of road lighting during darkness. However, there were indications on a daylight safety effect during fog, possibly due to guidance from light poles. The results from the studies described in this thesis give a basis for increasing the application of road lighting as a traffic safety measure worldwide. Cost – benefit calculations indicate that road lighting is one of the most efficient road safety measures available. However, the energy consumption related to road lighting is a problem that must be considered. The great challenge is to reduce the energy consumption as much as possible without reducing the safety benefit too much. Future road lighting will probably be of the adaptive type, and it will be essential to know how the safety effect varies according to traffic and weather conditions and how it varies with the road lighting level and the quality of the lighting. The thesis answers some question about the safety effect during different weather conditions. There is, however, too little information about safety effect related to varying road and traffic conditions. A more serious lack of knowledge is that we do not know how the safety effect varies according to the lighting level. It is not possible to balance the energy consumption and the safety effect as long as this relationship is not known.
49
Mullen, Carrie. "Quality Assurance of forensic investigations in toxicology and traffic safety." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5465/.
Abstract:
The work described in this thesis deals with three aspects of quality assurance in the field of forensic toxicology: proficiency testing schemes, validation of analytical methods for the piperazine group of abused drugs and validation of the police field impairment test, used at the roadside to test drivers for drug-induced impairment. Proficiency Testing: Long term reviews were performed for two forensic external quality assurance schemes. Rounds 30 (in 2007) to 48 (in 2012) of the UKAS-accredited commercial Quartz Forensic Blood Toxicology Proficiency Testing Scheme (PTS), and a ten year period from 1999 to 2009 of the freely-available United Nations Office on Drugs and Crime (UNODC) International Collaborative Exercises (ICE). Only limited ICE data could be made available as much of the original data had been stored on a database which had become obsolete, hence the data were only available as the original results forms provided to UNODC by the ICE participants. Data was entered to Microsoft Excel® spreadsheets and Microsoft Access® databases from the original forms for the years 1999, 2001 (2 rounds), 2003 (2 rounds) and 2005 (2 rounds), and summary data was extracted from the UNODC round reports for the years 2007, 2008 and 2009. Four methods of scoring quantitative performance were reviewed and the most suitable, a z-score using an assigned ‘true’ value and a percentage of the true value as acceptable deviation, was applied to reanalyse the participants’ results and assess their performance. Methods of scoring proficiency which relied upon participants’ data to determine acceptable variation were found merely to describe the data rather than challenge participants on whether or not they were performing fit-for-purpose analyses. Factors such as participation, analytes tested, participants’ methods of analysis and participants performance were summarised for each scheme before the performance of the two schemes, and that of their participants, were compared. ICE tested more analytes per annum but from a smaller test menu than Quartz. This resulted in more repetitive testing and allowed for some trend analysis and performance monitoring. It was not possible to observe performance trends with Quartz due to the wide variety of analytes tested. The smaller array of potential analytes and more repetitive nature of ICE testing also meant that performance monitoring and detection of bias were easier to perform, and ICE was shown to be more effective as external quality assurance (EQA). Quartz provided a good educational resource as it incorporated the wide range of drugs which a forensic toxicology laboratory could realistically encounter. Following the review, however, it was recommended for QUARTZ that, to provide a safeguard against bias, more repetitive testing was required and this has now been adopted. Piperazines: All piperazine analogues are now illegal in the UK, registered as Class C of the Misuse of Drugs Act (1971) and schedule 2, part III of the Misuse of Drugs Regulations (2001). Piperazines can elicit similar effects to some ATS and methods for their detection should be available in forensic toxicology laboratories. In the present study, methods were developed for the detection of a range of piperazines in blood using LC-MS/MS (p-MeOPP, p-FPP, BZP, o-MeOPP, p-MPP and TFMPP) and GC-MS (p-FPP, BZP, TFMPP, p-MPP, o-MeOPP, m-CPP, p-MeOPP and p-CPP). Quality assurance required both methods to be validated. For all piperazine analytes accuracy was within ±15% (20% at low concentrations) and precision was within 15% (20% at low concentrations). For both methods LLOD of all analytes was 5 ng/ml of blood and upper limit of quantification was 2 µg/ml of blood. For the GC-MS method lower limits of quantification (LLOQs) were in the range 20 to 30 ng/ml of blood. For LC-MS/MS, LLOQs ranged from 50 to 60 ng/ml of blood, although quantification by the LC-MS/MS method was restricted by the lack of availability of appropriate internal standards. There were no apparent significant matrix effects and recovery by both methods was >60 % and, therefore, acceptable. Short term stability of the piperazine analytes was investigated. Piperazines remain sufficiently stable when stored in the fridge for at least one week, and are stable through three freeze-thaw cycles. There was no detectable degradation when blood samples were left on the bench-top or when extracted ‘in-process’ samples were left in the autosampler for up to 72 hours. The LC-MS/MS method could provide a readily applicable screening method. A small aliquot of a basic drug extract could be screened by LC-MS/MS for the presence of piperazines, leaving the majority of the extract for other analyses, for example, piperazines confirmation or amphetamines analysis. The GC-MS method was suitably validated to provide quantification but application to casework samples remains to be evaluated. It is recommended that piperazine testing be performed for all suspected MDMA or ‘club drug’ intoxication cases. The Field Impairment Test: The detection of drugged drivers primarily depends on the current method which is the driver field impairment test (FIT). FIT comprises measurement of pupil diameter and four physical tasks (the Romberg balance test, walk and turn test, one legged stand and finger to nose test) intended to simultaneously test comprehension, short term memory, balance and motor function. Despite FIT having ISO accreditation, it has been recognised that police officers lack confidence with the protocol and do not apply the test as often as is necessary. The main difficulty arises from the requirement to make a subjective judgement of impairment and officers lack confidence in their ability to do so. FIT has never been fully validated. The present study was designed to meet the urgent requirement to develop FIT into an objective measurement, by determining what constitutes “normal” performance in FIT by unimpaired adults of different ages. FIT performance was recorded for 79 individuals, a statistically determined cohort size, confirmed by breath and oral fluid analysis not to be under the influence of impairing substances. Each error made during FIT, as defined by the FIT standard operating procedure, was recorded and collated in a Microsoft Excel® spreadsheet for analysis. It was found that the definition of ‘errors’ was too stringent as many which are required to be recorded are normal physiological or behavioural characteristics, such as body sway, and most subjects would be unable to complete the task without displaying them. A less stringent, evidence-based definition of “error” was developed which allowed statistically more significant analysis to be performed on the FIT results. A statistically significant difference (P=0.00578) was shown to exist between the FIT performance of individuals under the age of forty years and those aged forty and over. Based on the principles of a PTS, robust mean and standard deviation were used to determine what constituted acceptable performance. Those in the younger age group could be considered impaired if the police officer witnessed more than seven errors, or, in the older age group, more than fifteen errors. Using these criteria the frequency of false positives, i.e. unimpaired drivers being assessed as impaired is estimated to be (less than 3%). Also, the ranges of errors observed in both groups was large and overlapped, such that it may be possible for an impaired person to appear unimpaired. This requires further investigation.
50
Autey, Jarvis. "Before and after traffic safety evaluations using computer vision techniques." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43598.
Abstract:
Traditionally, road safety analysis has been undertaken using historical collision records. This approach to road safety analysis is reactive in that the analyst has to wait for collisions to take place before an action can be taken. An alternative approach is to study traffic conflicts or near misses which occur more frequently, can be clearly observed and are related to collisions. However, there are issues of subjectivity, reliability, and cost associated with the use of human observers. The use of computer vision techniques to automate the process of collecting traffic conflicts data can help mitigate these problems. This thesis presents the results of a before-after safety evaluation of a proposed design for channelized right-turn lanes. The evaluation uses an automated safety analysis approach to identify and measure the severity of traffic conflicts. The new design, termed “Smart Channels”, decreases the angle of the channelized right turn to approximately 70 degrees, and is considered to have safety benefits for both vehicle-pedestrian and vehicle-vehicle interaction. Data for three treatment sites and one control site, located in British Columbia, Canada, are evaluated using automated traffic conflict analysis that relies on computer vision for conflict detection. The results of the evaluation show that the implementation of the right-turn treatment has resulted in a considerable reduction in the severity and frequency of merging, rear-end, and total conflicts. The total average hourly conflict was reduced by a statistically significant 51 percent, while the average conflict severity was reduced by a statistically significant 41 percent. Many different traffic conflict indicators have been proposed and studied, but the methods of combining the results has not been well examined. This thesis considers four conflict indicators and examines methods of combining or aggregating the information provided by each indicator in order to better account for all components of risk in traffic conflicts. The four indicators are time-to-collision, gap-time, deceleration-to-safety time, and post-encroachment time. Two primary aggregation methods are studied: time aggregation and road-user aggregation. Time aggregation is appropriate for determining aggregate severity over periods of time, and road-user aggregation is used for normalizing risk to the volume of users.