Journal articles: 'Intersection sight distance'

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Harwood, Douglas W., John M. Mason, and Robert E. Brydia. "Sight Distance for Stop-Controlled Intersections Based on Gap Acceptance." Transportation Research Record: Journal of the Transportation Research Board 1701, no. 1 (January 2000): 32–41. http://dx.doi.org/10.3141/1701-05.

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The current AASHTO policy for sight distance at Stop-controlled intersections is based on a model of the acceleration performance of a minor-road vehicle turning left or right onto a major road and the deceleration performance of the following major road vehicle. An alternative intersection sight distance model based on gap acceptance is developed and quantified. Field studies that were performed to determine the critical gaps appropriate for use in sight distance design are described. It is recommended that the sight distance along the major road for a passenger car at a Stop-controlled intersection should be based on a distance equal to 7.5 s of travel time at the design speed of the major road. Longer sight distances are recommended for minor-road approaches that have sufficient truck volumes to warrant consideration of a truck as the design vehicle.

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Lee, Soo-Beom, and William D. Berg. "Development of Safety-Based Level-of-Service Parameters for Two-Way Stop-Controlled Intersections." Transportation Research Record: Journal of the Transportation Research Board 1635, no. 1 (January 1998): 127–32. http://dx.doi.org/10.3141/1635-17.

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Current methods for evaluating level of service at two-way stop-controlled intersections do not account for safety considerations. One of the most important factors influencing intersection safety is the availability of adequate sight distance. However, current recommended intersection sight distance criteria do not explicitly consider variability in traffic composition, vehicle characteristics, pavement conditions, or driver characteristics such as perception-reaction time and minimum gap acceptance. Research was therefore undertaken to develop and validate a method where the safety of a two-way stop-controlled intersection could be estimated based on parameters such as intersection geometry, traffic volume, pavement condition, traffic composition, and available sight distances. Simulation modeling was used to estimate the frequency of potential conflicts or collisions resulting from sight distance restrictions. The potential severity of the collisions was modeled using kinetic energy principles. A method for incorporating the results into a level-of-service evaluation framework was then developed.

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Kilani, Omar, Maged Gouda, Jonas Weiß, and Karim El-Basyouny. "Safety Assessment of Urban Intersection Sight Distance Using Mobile LiDAR Data." Sustainability 13, no. 16 (August 18, 2021): 9259. http://dx.doi.org/10.3390/su13169259.

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This paper proposes an automated framework that utilizes Light Detection and Ranging (LiDAR) point cloud data to map and detect road obstacles that impact drivers’ field of view at urban intersections. The framework facilitates the simulation of a driver’s field of vision to estimate the blockage percentage as they approach an intersection. Furthermore, a collision analysis is conducted to examine the relationship between poor visibility and safety. The visibility assessment was used to determine the blockage percentage as a function of intersection control type. The safety assessment indicated that intersections with limited available sight distances (ASD) exhibited an increased risk of collisions. The research also conducted a sensitivity analysis to understand the impact of the voxel size on the extraction of intersection obstacles from LiDAR datasets. The findings from this research can be used to assess the intersection without the burden of manual intervention. This would effectively support transportation agencies in identifying hazardous intersections with poor visibility and adopt policies to enhance urban intersections’ operation and safety.

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Awadallah, Faisal. "Intersection sight distance analysis and guidelines." Transport Policy 16, no. 4 (August 2009): 143–50. http://dx.doi.org/10.1016/j.tranpol.2009.04.001.

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Achtemeier, Jacob, Curtis M. Craig, and Nichole L. Morris. "The Effects of Restricted Sight Distances on Drivers at Simulated Rural Intersections." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 63, no. 1 (November 2019): 2122–23. http://dx.doi.org/10.1177/1071181319631497.

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Short sight distances at rural intersections can result in reduced safety including drivers choosing smaller gaps between oncoming vehicles (Yan & Richards, 2010). Conversely, increased sight distances may result in improved driver confidence, but not safety as seen at rail crossings (Ward & Wilde, 1996). Thus, simply increasing sight distances may not result in linear gains in safety. Establishing appropriate lower and upper-visibility limits at rural intersections will minimize operational costs for clearing and grubbing labor and may reduce serious injury and fatal crashes by promoting safer crossing behavior around rural thru-STOP intersections. This driving simulation study will examine intersection visibility and other intersection design factors that influence driver behavior at rural thru-STOPs. Time to collision, or TTC, is a primary motivating factor on driver decisions to cross intersections. Drivers’ TTC perception is a function of oncoming vehicle speed, distance, and rate of retinal expansion (tau; Hancock & Manser, 1997). We hypothesize TTC factors may interact with confidence in intersection crossing judgments. Specifically, when people must quickly make judgments, their confidence must be estimated after the decision has been made, but if the time pressure is not high and the decision is not immediate, people’s judgments and their confidence in those judgments can both be considered prior to action. This can be problematic because people are normally overconfident in their judgments (Harvey, 1997). The present study comprised a crossing judgment block, and a mainline drive block. The experimental stimuli were validated by engineers with experience in rural intersections, who rated the simulated intersections as “significantly representative” to real-world intersections through an average rating score of 5.25 ( SD = 0.5) on a 7-pt scale. This was done to ensure that the study findings would be more likely to be applicable to world intersections. The goal of the study is to identify whether sight distance and other variables, including speed for the judgment task and vehicle proximity to the intersection for the mainline drive task, impact safety at rural intersections.

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Easa, Said M. "Reliability Approach to Intersection Sight Distance Design." Transportation Research Record: Journal of the Transportation Research Board 1701, no. 1 (January 2000): 42–52. http://dx.doi.org/10.3141/1701-06.

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The intersection sight distance (ISD) design presented by AASHTO is based on extreme values of the component design variables such as design speed, perception–reaction time (a high percentile), and friction coefficient (a low percentile). A reliability method is presented, based on AASHTO, that does not rely on extreme values but instead considers the moments (mean and variance) of the probability distribution of each random variable. The method also accounts for correlations among the component random variables. In Cases I and II of AASHTO, the variations of the sight distance along both legs of the intersection are considered for both design and evaluation. For evaluation (involving an exiting obstruction), these variations are combined into a single variable that determines whether the corresponding sight line is obstructed. In Case III, only the sight distance leg along the major road has variations. The proposed method is straightforward and involves simple, closed-form mathematics for calculating sight distance and associated reliability. Sensitivity of ISD to various design variables is examined. ISD reliability-based values for various cases are presented from data reported in the literature, and results are compared with current AASHTO design values.

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Easa, Said M., and Zain A. Ali. "Three-Dimensional Stop-Control Intersection Sight Distance." Transportation Research Record: Journal of the Transportation Research Board 1961, no. 1 (January 2006): 94–103. http://dx.doi.org/10.1177/0361198106196100111.

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Salwan, Akshay, Said M. Easa, Narayana Raju, and Shriniwas Arkatkar. "Intersection Sight Distance Characteristics of Turbo Roundabouts." Designs 5, no. 1 (March 8, 2021): 16. http://dx.doi.org/10.3390/designs5010016.

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A turbo roundabout uses spiral circulatory roads for effectively counteracting the problems faced in modern multilane roundabouts. First developed in 1996, the turbo roundabout has an advantage over the conventional roundabout regarding capacity and safety. Turbo roundabouts are still in the developing phase in North America, but even in the European subcontinent where they exist in large numbers, reliable analytical studies on the critical parameters of roundabout visibility are lacking. Visibility (sight distance) helps to shape the geometry of the intersection and aids in safety. This paper presents the mathematical characteristics of the intersection geometry and intersection sight distance (ISD) of the turbo roundabout. Mathematical formulas are presented for the sight distance from the approaching vehicle to the conflicting-entering and circulating vehicles. The maximum lateral clearances to the conflicting vehicles are derived using mathematical optimization. The developed analytical method is verified graphically using AutoCAD. To assist in practical applications, design aids for the maximum lateral clearance are presented. The presented method and design aids should aid in promoting safety at turbo roundabouts.

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Himes, Scott, Kim Eccles, Kara Peach, Christopher M. Monsere, and Timothy J. Gates. "Estimating the Safety Effects of Intersection Sight Distance at Unsignalized Intersections." Transportation Research Record: Journal of the Transportation Research Board 2588, no. 1 (January 2016): 71–79. http://dx.doi.org/10.3141/2588-08.

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Himes, Scott, Richard J. Porter, and Kimberly Eccles. "Safety Evaluation of Geometric Design Criteria: Intersection Sight Distance at Unsignalized Intersections." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 39 (July 15, 2018): 11–19. http://dx.doi.org/10.1177/0361198118783162.

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A Policy on Geometric Design of Highways and Streets, 6th Edition, (publisher: AASHTO), provides design criteria for minimum sight distances, including intersection sight distance (ISD). An understanding of the relationship between ISD and safety at stop-controlled intersections is needed, with potential applications of this knowledge to both performance-based design and substantive road safety management practices. To establish this relationship, crash, traffic, and geometric data were collected from 832 two-lane minor unsignalized intersection approaches in Ohio, and Washington. The data were analyzed using a cross-sectional study design to quantify the relationship between safety and ISD. The analyses indicated that the expected number of target crashes are associated with available ISD. Target crash frequencies increase as available ISD decreases. Results suggest that ISD is associated with expected crash frequency in a non-linear fashion. The sensitivity of the expected number of target crashes to changes in ISD is highest when ISD is shorter, and decreases as ISD increases (i.e., the safety benefit of increasing ISD from 300 to 600 ft is substantially larger than the safety benefit of increasing ISD from 1,000 to 1,300 ft). The results also suggest that the impacts of ISD on crash frequencies vary as a function of the major road two-way annual average daily traffic and the major road speed limit. The sensitivity of the expected number of crashes to changes in ISD increases as both traffic volume and speed limit increase. Crash modification functions for each of the target crash types were estimated using the regression models.

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Easa, Said M., Yang Ma, Shixu Liu, Yanqun Yang, and Shriniwas Arkatkar. "Reliability Analysis of Intersection Sight Distance at Roundabouts." Infrastructures 5, no. 8 (August 6, 2020): 67. http://dx.doi.org/10.3390/infrastructures5080067.

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This paper presents a reliability-based method for the design of intersection sight distance (ISD) at traffic roundabouts using the linear and nonlinear deceleration profiles of the entry vehicles. The reliability method is based on the first-order second moment method which is simple and relatively accurate compared with advanced methods. The nonlinear deceleration profile includes a shape parameter that produces the linear profile as a special case. Deterministic and reliability-based formulas for the required ISD for an approaching vehicle are developed for the entry vehicle on the left and the vehicle on the circulating roadway. Then, the design values of the ISD legs, applicable to any type of roundabout, are presented for different probabilities of non-compliance (Pnc) and different coefficients of variations. For the special case of single-lane symmetrical roundabouts, which have a well-defined geometry, the lateral clearance needs are established. The sensitivity analysis shows that ISD is very sensitive to both the mean and variance of the critical headway. The results show that the deterministic method results in ISD values that correspond to a very small Pnc, indicating that the method is very conservative. The proposed method, which provides flexibility in selecting ISD for any given Pnc, should be of interest to highway designers and practitioners to promote roundabout safety.

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Khattak, Aemal J., Shauna Hallmark, and Reginald Souleyrette. "Application of Light Detection and Ranging Technology to Highway Safety." Transportation Research Record: Journal of the Transportation Research Board 1836, no. 1 (January 2003): 7–15. http://dx.doi.org/10.3141/1836-02.

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An application of light detection and ranging (LIDAR) technology to highway intersection safety is presented. LIDAR can be used to collect information about a surface by reflecting thousands of light beams per second off the surface and measuring the return time of the beams. The surface profile is collected as a digital signature that can be used in a variety of applications. Collection of information on the surface profile of the earth in the form of elevation data is one of several LIDAR applications that have been used for mapping and contouring. The focus of the described application is use of LIDAR elevation data to obtain information on intersection geometry that can lead to the discovery of potential obstructions in driver sight lines. After appropriate transformations, LIDAR elevation data were used in line-of-sight analysis to obtain information on sight-line obstructions at six intersections on the IA-1 corridor in Iowa. Intersection crash frequency and data availability were considerations in the selection of the six intersections. Results from the line-of-sight analysis were validated by visits to the intersections in the field and verification of the existence of obstructions detected during the analysis. Sixty-six lines of sight were blocked during the line-of-sight analysis, of which 62 (89.8%) were confirmed during the validation process. Four (5.8%) sight-line obstructions were not confirmed during the validation. At least three (4.4%) potential sight-line obstructions discovered during validation were not detected during the line-of-sight analysis. The intersection with the highest crash frequency was correctly found to have obstructions located within the intersection sight triangles. It can be concluded that LIDAR elevation data can be used successfully for identifying potential sight-distance problems at intersections. Identified potential problems can be verified and rectified in the field. LIDAR is a relatively costly data source, and a single application, such as this one, cannot justify the high cost of LIDAR data acquisition. Other potential highway safety enhancing applications of LIDAR must be investigated to offset the high data-acquisition cost. Suggestions for other highway safety applications are provided.

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Jung, Jaehoon, Michael J. Olsen, David S. Hurwitz, Alireza G. Kashani, and Kamilah Buker. "3D virtual intersection sight distance analysis using lidar data." Transportation Research Part C: Emerging Technologies 86 (January 2018): 563–79. http://dx.doi.org/10.1016/j.trc.2017.12.004.

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Easa, Said M., Essam Dabbour, and Muhammad Z. A. Ali. "Three-Dimensional Model for Stop-Control Intersection Sight Distance." Journal of Transportation Engineering 130, no. 2 (March 2004): 261–70. http://dx.doi.org/10.1061/(asce)0733-947x(2004)130:2(261).

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Tawfeek, Mostafa H., and Karim El-Basyouny. "Location-based analysis of car-following behavior during braking using naturalistic driving data." Canadian Journal of Civil Engineering 47, no. 5 (May 2020): 498–505. http://dx.doi.org/10.1139/cjce-2019-0314.

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This study investigates the car-following behavior during braking at intersections and segments. Car-following events were extracted from a naturalistic driving dataset, mapped using ArcGIS, and analyzed to differentiate between the intersection- and segment-related events. The intersection-related events were identified according to an intersection influence area, which was estimated based on the stopping sight distance and the speed limit. Five behavioral measures were quantified based on exploring the probability density functions (PDF) for intersection- and segment-related events. The results showed that there were significant differences between the PDFs of the measures for both cases. Moreover, it was indicated that drivers tend to be more aggressive at intersections compared with segments. Thus, it is crucial to consider the driver’s location when investigating driver behavior. The quantified behavioral measures are a rich data source that can be used for car-following microscopic modeling, surrogate safety analysis, and driver assistance systems development.

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Hassan, Yasser, Said M. Easa, and A. O. Abd El Halim. "Analytical Model for Sight Distance Analysis on Three-Dimensional Highway Alignments." Transportation Research Record: Journal of the Transportation Research Board 1523, no. 1 (January 1996): 1–10. http://dx.doi.org/10.1177/0361198196152300101.

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Existing sight distance models are applicable only to two-dimensional (2-D) separate horizontal and vertical alignments or simple elements of these separate alignments (vertical curve, horizontal curve). A new model is presented for determining the available sight distance on 3-D combined horizontal and vertical alignments. The model is based on the curved parametric elements that have been used in the finite element method. The elements presented are rectangular (4-node, 6-node, and 8-node elements) and triangular. These elements are used to represent various features of the highway surface and sight obstructions, including tangents (grades), horizontal curves, vertical curves, traveled lanes, shoulders, side slopes, cross slopes, superelevation, lateral obstructions, and overpasses. The available sight distance is found analytically by examining the intersection between the sight line and the elements representing the highway surface and the sight obstructions. Application of the new model is illustrated using numerical examples, and the results show that existing 2-D models may underestimate or overestimate the available sight distance. The proposed model should be valuable in establishing design standards and guidelines for 3-D highway alignments and determining the effect of various highway features on sight distance.

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Yuan, Li, and Jian Lu. "Safety Evaluation and Improvements for Highway Intersections." Transportation Research Record: Journal of the Transportation Research Board 2060, no. 1 (January 2008): 46–52. http://dx.doi.org/10.3141/2060-06.

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Intersection safety is one of the most important issues in transportation. Traffic crash analysis—the most popular method to evaluate or assess the safety performance of an intersection—has been used for a long time. However, it is based on a lot of crash data, which need to be accumulated over a long period. In addition, traffic crashes sometimes occur randomly as a result of human driving behavior. Therefore, without sufficient data and crash history, traffic crash analysis may not give an overall evaluation of an intersection's safety performance. This paper introduces an approach to evaluating highway intersection safety performance. It is fully based on the existing conditions of the intersection, including geometrics, sight distance, pavement surface conditions, traffic control devices, traffic signal timing, and phasing. The non-accident-based approach is based on field surveys under the conditions mentioned previously. The approach will also result in a safety index to indicate the safety performance of the intersection. Corresponding countermeasures are ranked and recommended based on cost–benefit analysis. This paper is based on research results from part of a project (entitled Safety Design of Highway Intersections) sponsored by the China Department of Transportation. In this paper, the approach (called a diagnostic approach) is practically applied to evaluate the safety performance of some intersections in Shan Dong Province. Results from the real application indicate that the approach has good applicability and can be used by field safety engineers in real applications.

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Pein, Wayne. "Bicyclist Performance on a Multiuse Trail." Transportation Research Record: Journal of the Transportation Research Board 1578, no. 1 (January 1997): 127–31. http://dx.doi.org/10.3141/1578-16.

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Bicyclist crossing time from a full stop was measured using video recording equipment at 16 diverse trail-roadway intersections (two to six lanes, stop or signal controlled, divided or undivided) of the Pinellas Trail in Pinellas County, Florida. A total of 442 bicyclists (single individuals or randomly selected individuals from a group) were timed. The cruising speed of 65 bicyclists was also determined. A linear regression model was fit to the time and crossing-distance data. A linear regression was also fit to eight 85th percentile crossing-time points that were calculated from grouped raw data. Using kinematic physics, in which bicycle acceleration and intersection crossing velocity are variables, a theoretical equation was derived to predict bicyclist crossing time for any distance. This derived equation is a linear function of distance, so the regression coefficients could then be used to estimate bicyclist crossing velocity and acceleration on the Pinellas Trail. These estimated values for bicyclist acceleration and intersection crossing velocity compare favorably with the scant available data from foreign and domestic sources. Thus, the crossing-time prediction equation can be a useful tool when designing intersections for bicyclists, with application in signal timing and crossing-sight distance calculations.

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Yan, Xuedong, and Essam Radwan. "Geometric Models to Calculate Intersection Sight Distance for Unprotected Left-Turn Traffic." Transportation Research Record: Journal of the Transportation Research Board 1881, no. 1 (January 2004): 46–53. http://dx.doi.org/10.3141/1881-06.

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Easa, Said M. "Design Guidelines for Symmetrical Single-Lane Roundabouts Based on Intersection Sight Distance." Journal of Transportation Engineering, Part A: Systems 143, no. 10 (October 2017): 04017052. http://dx.doi.org/10.1061/jtepbs.0000081.

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Ali, M. Z. A., Said M. Easa, and M. Hamed. "Stop-Controlled Intersection Sight Distance: Minor Road on Tangent of Horizontal Curve." Journal of Transportation Engineering 135, no. 9 (September 2009): 650–57. http://dx.doi.org/10.1061/(asce)0733-947x(2009)135:9(650).

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Gattis, J. L., and Sonny T. Low. "Intersection Angle Geometry and the Driver’s Field of View." Transportation Research Record: Journal of the Transportation Research Board 1612, no. 1 (January 1998): 10–16. http://dx.doi.org/10.3141/1612-02.

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At a skewed-angle intersection with the acute angle to the right of a driver on the minor roadway (the approach required to stop or yield), the vehicle body may obstruct the minor-road driver’s line of sight. Body parts that may obstruct the line of sight include the door frame, a panel aft of the door, or the cargo box of a single-unit truck. If the combination of vehicle design and intersection skew angle restrict a driver’s line of sight to the right, safety may be compromised. This research project evaluated obstructions caused by the bodies of a number of vehicles. The researchers measured the angles at which drivers’ lines of sight were obstructed by the body of their vehicles. Two driving positions were used—“sit back” and “lean forward.” A 13.5-degree vision angle (with respect to a line perpendicular to the vehicle path) was selected to represent an intermediate posture between the sit-back and the lean-forward positions. With a 13.5-degree vision angle in some restrictive vehicles, the 60-degree minimum intersection angle allowed by A Policy on Geometric Design of Highways and Streets (“Green Book”) will cause the driver’s line of sight to be obstructed by the vehicle itself and offer only limited sight distance. When the acute angle is to the minor-road driver’s right, minimum angles of 70 degrees or more may be more appropriate, depending on the through-road speed.

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Koike, Hirotaka, Akinori Morimoto, and Atsushi Kitazawa. "Unevenness of Intersection Pavement and Bicycle Safety." Transportation Research Record: Journal of the Transportation Research Board 1846, no. 1 (January 2003): 56–61. http://dx.doi.org/10.3141/1846-10.

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Bicycles are environmentally friendly and easy to operate. However, the bicycling environment in Japan is inadequate compared with many developed countries. Bicycle accidents have been increasing in recent years, and safety measures are needed to improve the bicycling environment. Although road surface conditions have improved, as reflected in the recent barrier-free policy for elderly and disabled pedestrians, an uneven surface between the road and the crosswalk can help to reduce accidents by reducing running speed. Because the most frequent type of bicycle accident is a collision with a car at an intersection, the accident-prevention potential of an uneven surface at an intersection crosswalk was examined. Students were asked to run along specific routes, and speed and vibration changes when they passed through intersections were measured. On the basis of the results, an analysis was made of what road environments would benefit from an uneven crossing surface. An uneven surface was found to reduce speeds at intersections with limited sight distance. However, other appropriate safety measures must be applied to reduce bicycle speed when an uneven crossing surface cannot be used because of the barrier-free policy.

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Fitzpatrick, Kay, Torsten Lienau, and Daniel B. Fambro. "Driver Eye and Vehicle Heights for Use in Geometric Design." Transportation Research Record: Journal of the Transportation Research Board 1612, no. 1 (January 1998): 1–9. http://dx.doi.org/10.3141/1612-01.

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Driver eye, headlight, taillight, and vehicle heights are important elements for determining passing and intersection sight distances and horizontal and vertical curve lengths to provide required stopping sight distance. Driver eye and object heights have varied significantly since their inception in the 1920s, when their values were suggested as 1676 mm. The objective of this study was to determine appropriate driver eye, headlight, taillight, and vehicle heights for use in developing geometric design criteria. The results of this research were used to recommend a driver eye height of 1080 mm for design purposes. This value represents 90 percent of the passenger car driver eye height values and an even higher percentage of the total vehicle fleet, because passenger cars have the lowest driver eye height values and represent fewer than two-thirds of the total vehicle fleet. Headlight and taillight heights of 600 mm are recommended for design. These values represent over 90 and 95 percent of the passenger cars observed in this study, respectively. The vehicle height recommendation for sight distance was 1315 mm, which represents the 10th percentile passenger car height values measured in the research.

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Olukanni, David, David Enetomhe, Gideon Bamigboye, and Daniel Bassey. "A Time-Based Assessment of Particulate Matter (PM2.5) Levels at a Highly Trafficked Intersection: Case Study of Sango-Ota, Nigeria." Atmosphere 12, no. 5 (April 22, 2021): 532. http://dx.doi.org/10.3390/atmos12050532.

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Vehicle emissions have become one of the most prevailing air contamination sources, including nitrogen oxides, volatile organic compounds, carbon monoxide and particulate matter (PM). Among other air pollutants, PM limits visible sight distance and poses health risks upon inhalation into the human body. This study focused on assessing PM2.5 concentrations in air at different periods of the day at the highly trafficked grade-separated intersection of Sango-Ota, Ogun State, Nigeria. PM2.5 readings were taken at three at-grade points around the intersection’s roundabout between 10:00 a.m. and 5:00 p.m. for four (4) days using the BR-SMART-126 Portable 4-in-1 air quality monitor. The highest level of PM2.5 obtained on Day 1 (Monday) and Day 4 (Thursday) was about 45.1% and 38.6%, respectively, lower than that of Day 3 (Wednesday). The highest concentrations of PM2.5 were recorded between 11:00 and 13:00 and between 16:00 and 18:00 (up to 217 µg/m3) whereas the lowest levels were recorded between 14:00 and 15:00 (as low as 86 µg/m3). The concentration of PM2.5 at the Sango-Ota intersection is adjudged “very poor” with average hourly concentrations between 97 and 370 µg/m3. Outcomes obtained indicate the need for improved measures to control air quality along major road corridors and at intersections in Ogun State and Nigeria at large.

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FUJIWARA, Akimasa, Yoriyasu SUGIE, Toshiyuki OKAMURA, and Moto EGUSA. "Relationship between Traffic Accident and Sight Distance to Signal at Intersection close to Bridge with Downhill." INFRASTRUCTURE PLANNING REVIEW 18 (2001): 803–8. http://dx.doi.org/10.2208/journalip.18.803.

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Wang, Jin, and Huaguo Zhou. "Using Naturalistic Driving Study Data to Evaluate the Effects of Intersection Balance on Driver Behavior at Partial Cloverleaf Interchange Terminals." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 38 (May 23, 2018): 255–65. http://dx.doi.org/10.1177/0361198118774670.

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Past studies showed that poor intersection balances at partial cloverleaf (parclo) interchange terminals significantly impact traffic safety and sight distance of drivers making left turns to entrance ramps. Some state traffic agencies have recommended a “balance” guideline that the length between the left-turn stop line on crossroads to the middle of the intersection should not be greater than 60% of the entire length of the intersection. However, a scarcity of research exists on how the balance of an intersection affects driver behavior, which has been identified as a critical contributing factor to intersection-related crashes. This study utilizes the Naturalistic Driving Study (NDS) data to evaluate the effects of intersection balance on driver behavior at parclo interchange terminals for proof-of-concept. A small but representative data sample was collected from the second Strategic Highway Research Program’s (SHRP 2) NDS dataset. It demonstrates statistical characteristics and overall trends of driver speed, acceleration/deceleration rates, and risk perception with the changing of intersection balances. Conclusions provide guidance on optimal intersection balance design that may help drivers make smoother and safer transitions from crossroads to entrance ramps at parclo interchange terminals.

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Tarawneh, Mohammed S., and Patrick T. Mccoy. "Effect of Offset between Opposing Left-Turn Lanes on Driver Performance." Transportation Research Record: Journal of the Transportation Research Board 1523, no. 1 (January 1996): 61–72. http://dx.doi.org/10.1177/0361198196152300108.

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The objective of the research described here was to study the effects of the offset between opposing left-turn lanes on the turning performance of drivers with respect to driver age and gender. Left-turn performance of 100 subjects within three age groups (25–45, 65–74, and 75+ years old) was evaluated under normal driving conditions at four intersections of different left-turn offset configurations. The results indicate that driver performance can be adversely affected by offsets that are much less (i.e., more negative) than the negative 0.9-m offset. Such large negative offsets significantly increase the size of the critical gaps of drivers turning left and also seem to increase the likelihood of conflicts between left turns and opposing through traffic. Large negative offsets may be particularly troublesome for older drivers and women drivers, who are less likely to position their vehicles within the intersection to see beyond vehicles in the opposing left-turn lane. Surprisingly, driver perceptions of the level of comfort and degree of difficulty were not found to improve with the increased sight distance provided by larger (i.e., more positive) offsets. The 1.8-m positive offset was associated with a lower level of comfort and a higher degree of difficulty perceived by drivers making left turns than the 0.9-m negative offset, which provided less sight distance. This may have been because the 0.9-m negative offset is much more common than the 1.8-m positive offset.

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Osama, Ahmed, Tarek Sayed, and Said Easa. "Framework for evaluating risk of limited sight distance for permitted left-turn movements: case study." Canadian Journal of Civil Engineering 43, no. 4 (April 2016): 369–77. http://dx.doi.org/10.1139/cjce-2015-0498.

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A reliability analysis framework is used to evaluate the risk of limited sight distance for permitted left-turn movements due to the presence of opposing left-turn vehicles. Two signalized intersection approaches in the city of Surrey were used as case studies for the framework. Geometric and traffic video data was collected and analyzed using a computer vision tool to extract the input variables probability distributions. The data was used in the reliability analysis where first-order and Importance Sampling methods were performed. The analysis showed that the probability of non-compliance was considerable at one approach due to its large left-turn lane offset. The analysis also showed that the probability of non-compliance increased substantially when the obstacle vehicle was a bus rather than a passenger car. Moreover, the time gap had a higher impact on the probability of non-compliance compared to speed. Strategies were suggested to overcome the high probability of non-compliance.

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Kindler, Carrie, Richard M. Wood, Douglas W. Harwood, Timothy R. Neuman, Ingrid B. Potts, and Nicholas Antonucci. "Intersection Diagnostic Review Module: Expert System for Geometric Design Review of Intersections on Rural Two-Lane Highways." Transportation Research Record: Journal of the Transportation Research Board 1851, no. 1 (January 2003): 3–12. http://dx.doi.org/10.3141/1851-01.

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FHWA has sponsored the development of an expert system for diagnostic review of at-grade intersections on rural two-lane highways as a component of the Interactive Highway Safety Design Model (IHSDM). This system, the Intersection Diagnostic Review Module (IDRM), has been developed because conventional design practices and design review procedures often fail to explicitly address the safety consequences of geometric design decisions. In particular, combinations of geometric features may pose safety problems that current design policies do not address (e.g., an intersection in combination with a sharp horizontal curve and a steep grade). The expert system allows such problems to be identified and evaluated in an automated and organized fashion. The structure and knowledge base of this expert system are presented. The system identifies potential safety problems in an intersection design by applying decision rules based on models that quantify the extent to which particular problems may or may not be present. Established geometric design models (such as the sight distance models used in current design policies) as well as new models that have been developed from literature synthesis and judgments by geometric design and safety experts are included. The models that IDRM uses to identify potential safety problems and the threshold values used to determine whether particular problems exist are described. IDRM provides a series of advisory messages indicating design features that should be reviewed for potential safety-related concerns. The advisory messages are based on the nature and extent of concerns identified by comparison with established threshold values.

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KIM, Dong Hyeop, Sarang JOKHIO, and Jin-Tae KIM. "Study on Operational Efficiency of Intersection with Safety Warning Information Overcoming Disqualified Drivers’ Sight Distance in Port Area." Journal of Korean Society of Transportation 38, no. 5 (October 31, 2020): 404–13. http://dx.doi.org/10.7470/jkst.2020.38.5.404.

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Wu, Lina, Jiangwei Chu, Yusheng Ci, Shumin Feng, and Xingwang Liu. "Engineering Solutions to Enhance Traffic Safety Performance on Two-Lane Highways." Mathematical Problems in Engineering 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/762379.

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Improving two-lane highway traffic safety conditions is of practical importance to the traffic system, which has attracted significant research attention within the last decade. Many cost-effective and proactive solutions such as low-cost treatments and roadway safety monitoring programs have been developed to enhance traffic safety performance under prevailing conditions. This study presents research perspectives achieved from the Highway Safety Enhancement Project (HSEP) that assessed safety performance on two-lane highways in Beijing, China. Potential causal factors are identified based on proposed evaluation criteria, and primary countermeasures are developed against inferior driving conditions such as sharp curves, heavy gradients, continuous downgrades, poor sight distance, and poor clear zones. Six cost-effective engineering solutions were specifically implemented to improve two-lane highway safety conditions, including (1) traffic sign replacement, (2) repainting pavement markings, (3) roadside barrier installation, (4) intersection channelization, (5) drainage optimization, and (6) sight distance improvement. The effectiveness of these solutions was examined and evaluated based on Empirical Bayes (EB) models. The results indicate that the proposed engineering solutions effectively improved traffic safety performance by significantly reducing crash occurrence risks and crash severities.

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Naylor, David W., and Johnny R. Graham. "Intersection Design and Decision–Reaction Time for Older Drivers." Transportation Research Record: Journal of the Transportation Research Board 1573, no. 1 (January 1997): 68–71. http://dx.doi.org/10.3141/1573-11.

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Trends in automobile and roadway use have changed drastically over the past several years. Changes in the trends include an increase in the percentage of licensed drivers, annual miles driven, and an increase in the number of older drivers. Of particular concern is the increase in the number of older drivers and the question of whether the current design standards adequately meet the needs of the older driver. In this study, the perception-reaction time variable used in calculating intersection sight distance at stop sign-controlled intersections was evaluated. The current design value for the perception–reaction time is 2.0 sec, which has been used since the 1940s when the driving population was much younger. A field experiment was performed to determine an appropriate value for today’s driving population. Subjects were covertly videotaped as they entered two rural and two urban stop sign-controlled interactions. Mean decision–reaction times were determined for an older and a younger group of subjects. The older group, consisting of 104 subjects, averaged 69.3 years of age and had a mean decision–reaction time of 1.32 sec. A group of 104 younger subjects, less than 30 years of age, had a mean decision–reaction time of 1.24 sec. The 85th percentile decision–reaction time for the older group was 1.86 sec and for the younger group, 1.66 sec. Both times were less than the current AASHTO design value of 2.0 sec.

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Dabbour, Essam. "Design Gap Acceptance for Right-Turning Vehicles Based on Vehicle Acceleration Capabilities." Transportation Research Record: Journal of the Transportation Research Board 2521, no. 1 (January 2015): 12–21. http://dx.doi.org/10.3141/2521-02.

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The current geometric design guide provides a methodology to analyze intersection sight distance for right-turning vehicles at signalized and two-way stop-controlled intersections based on the gaps accepted by the majority of drivers as measured from the field. That methodology is based mainly on driver behavior without considering the actual capabilities of the turning vehicle when accelerating from rest to the speed of the cross-traffic stream. This paper introduced the new design gap concept, which was based on the actual distance and time needed for the turning vehicle to accelerate to the same speed of the cross-traffic stream to avoid a collision. The acceleration capabilities of the turning vehicle were based on field measurements collected by GPS data logger devices that recorded the positions and instantaneous speeds of different turning vehicles at 1-s intervals; based on that, regression models were developed to establish an acceleration profile for a typical vehicle turning to the right from rest. Design tables were provided to help road designers select appropriate design gaps needed for different design speeds and grades of the crossing roadways. In comparison to the new design gaps, the measured gaps used in design were found to be generally inadequate. After implementation of the newly developed design gaps, turning drivers will potentially be able to accelerate comfortably without forcing other drivers in the cross-traffic stream to reduce their speeds or to change lanes to avoid colliding with turning vehicles.

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Lerner, Neil. "Age and Driver Time Requirements at Intersections." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 38, no. 14 (October 1994): 842–46. http://dx.doi.org/10.1177/154193129403801410.

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Current highway design models for required sight distance at stop-sign controlled intersections assume that the perception-reaction time (PRT) required is 2.0 seconds. That is, a 2.0 second interval to perceive, evaluate, decide, and initiate a response, is adequate to cover the range of time it takes real drivers to do this. This experiment evaluated the adequacy of the 2.0 second PRT assumption, including specific consideration of older drivers, who are known to experience relatively greater difficulty at intersections. Subjects in three age groups (20–40; 65–69; and 70+ years old) drove their own vehicles (fitted with a computer-controlled video-based data collection system) over a route that included 14 stop-controlled intersections. At each stop sign, they were required to make ratings of “road quality;” this broke visual search, and provided an opportunity for the experimenter to precisely define the initiation of search and the initiation of forward movement (thus defining PRT). The 2.0 second PRT assumption was found to work reasonably well for all age groups, and corresponded to roughly the 85th percentile PRT for all subjects. PRTs for older subjects were slightly (but significantly) briefer than for younger drivers. Reasons for not observing a slowing of intersection PRT with advancing age are discussed. The findings are also compared to gap acceptance data from another experiment. Even though the present experiment did not find objective evidence of older drivers requiring longer decision times, older subjects nonetheless demanded longer gaps in traffic in order to judge it safe to enter traffic.

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Hochmuth, Jonathan, and Ron Van Houten. "Influence of Advanced Placement of the In-Street Sign Gateway on Distance of Yielding from the Crosswalk." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 35 (May 23, 2018): 13–20. http://dx.doi.org/10.1177/0361198118776480.

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A multiple-threat accident occurs when a pedestrian attempts to traverse a crosswalk on a multilane road, and the vehicle nearest to the pedestrian yields close to the crosswalk, obscuring the pedestrian’s view of the next lane, and the motorist’s view in the adjacent lane of the pedestrian. This set of circumstances may lead to pedestrians being struck at higher speeds by a vehicle in the adjacent oncoming lane, often resulting in serious injury or a fatality. The present study compared advanced placement of a gateway in-street sign configuration with a gateway deployed at the crosswalk, on two multilane roads. Data were collected using a reversal design, capturing alternating series of data points in each condition, and counterbalancing the order of those conditions. The advanced placement of the sign produced comparable levels of yielding to the crosswalk placement, but produced a large increase in the proportion of yielding 50 ft or further from the crosswalk. On multilane roads, increasing the distance at which vehicles yield from the crosswalk mitigates the sight distance issues that produce multiple-threat accidents, thereby reducing the likelihood of pedestrian fatalities or serious injuries. Advanced placement of the gateway configuration may also take the signs out of the turning radii of larger vehicles at a driveway or intersection, which may improve the longevity of the in-street signs.

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Byrd, Patrick S., Patrick T. McCoy, Geza Pesti, and Virendra A. Singh. "Implementation of Wider Lane Lines to Improve Sight Distance from Opposing Left-Turn Lanes." Transportation Research Record: Journal of the Transportation Research Board 1708, no. 1 (January 2000): 12–19. http://dx.doi.org/10.3141/1708-02.

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Vehicles turning left at intersections from opposing left-turn lanes often restrict each other’s sight distance. Previous research has developed guidelines for offsetting opposing left-turn lanes to provide adequate sight distances. Implementation of these guidelines at existing intersections typically involves reconstructing the left-turn lanes. However, the results of the before-and-after studies presented demonstrate that increasing the width of the lane lines between left-turn lanes and the adjacent through lanes also can be used as a means of improving the sight distance between opposing left-turn lanes. Regression analysis was used to determine a relationship between lane-line width and available sight distance that can be used to design lane-line widths that provide the required sight distance for opposing left-turn vehicles.

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Hadiwardoyo, Seilendria A., Andrés Tomás, Enrique Hernández-Orallo, Carlos T. Calafate, Juan-Carlos Cano, and Pietro Manzoni. "Empirical Study and Modeling of Vehicular Communications at Intersections in the 5 GHz Band." Mobile Information Systems 2017 (2017): 1–15. http://dx.doi.org/10.1155/2017/2861827.

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Event warnings are critical in the context of ITS, being dependent on reliable and low-delay delivery of messages to nearby vehicles. One of the main challenges to address in this context is intersection management. Since buildings will severely hinder signals in the 5 GHz band, it becomes necessary to transmit at the exact moment a vehicle is at the center of an intersection to maximize delivery chances. However, GPS inaccuracy, among other problems, complicates the achievement of this goal. In this paper we study this problem by first analyzing different intersection types, studying the vehicular communications performance in each type of intersection through real scenario experiments. Obtained results show that intersection-related communications depend on the distances to the intersection and line-of-sight (LOS) conditions. Also, depending on the physical characteristics of intersections, the presented blockages introduce different degrees of hampering to message delivery. Based on the modeling of the different intersection types, we then study the expected success ratio when notifying events at intersections. In general, we find that effective propagation of messages at intersections is possible, even in urban canyons and despite GPS errors, as long as rooftop antennas are used to compensate for poor communication conditions.

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Xie, Yilin, Qing Wang, Lianbi Yao, Xiaolin Meng, and Yusong Yang. "Integrated Multi-Sensor Real Time Pile Positioning Model and Its Application for Sea Piling." Remote Sensing 12, no. 19 (October 3, 2020): 3227. http://dx.doi.org/10.3390/rs12193227.

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The traditional pile positioning method for offshore piling uses the intersection of lines of sight with two or three theodolites. This method has certain limits, including using post-mission pile positioning, being time-consuming and lacking position accuracy. A novel pile positioning model using four kinds of sensors (GNSS—Global Navigation Satellite System receivers, tiltmeters, laser rangefinders and calibrated CCD cameras) for sea piling was developed. Firstly, with Real Time Kinematics (RTK) GNSS and tiltmeter data, the piling ship’s position and attitude was achieved in real time, and then the coordinates of the pile center in the Ship Fixed Coordinate System (SFCS) were calculated by a laser rangefinder and a CCD camera data. Finally, using the coordinate transformation, the coordinates of the pile center construction were figured out and used to guide the pile movement to the right place in real time. Because of the poor RTK GNSS vertical accuracy (normally 2–3 cm) and complex piling ship structure, it is difficult to get the accurate penetration value per hammering, which is a very important parameter for structural engineers. A Scale Invariant Feature Transform (SIFT) algorithm was created to get the pixel difference between the two pile images captured before and after one hammering, respectively, which was then used to calculate the penetration. A case study on the piling ship named “YangShanHao” with the sensors and algorithms was also described and discussed in the paper. The results showed the high accuracy of the proposed position model and the pile sinking distance of the pixel, thanks to the SIFT algorithm.

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Easa, Said M., and Altaf Hussain. "Reliability of sight distance at stop-control intersections." Proceedings of the Institution of Civil Engineers - Transport 169, no. 3 (June 2016): 138–47. http://dx.doi.org/10.1680/jtran.14.00090.

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Easa, Said M. "Model for Sight-Distance Analysis of Uncontrolled Intersections." Journal of Transportation Engineering 124, no. 2 (March 1998): 156–62. http://dx.doi.org/10.1061/(asce)0733-947x(1998)124:2(156).

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Zwahlen, Helmut T., and Thomas Schnell. "Visual Detection and Recognition of Fluorescent Color Targets Versus Nonfluorescent Color Targets as a Function of Peripheral Viewing Angle and Target Size." Transportation Research Record: Journal of the Transportation Research Board 1605, no. 1 (January 1997): 28–40. http://dx.doi.org/10.3141/1605-05.

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Daytime conspicuity of targets with fluorescent and nonfluorescent backgrounds as a function of the peripheral angle and the target size was investigated in the field. The resulting peripheral detection and recognition data may prove relevant to, for example, a bicyclist or a pedestrian approaching a driver at an intersection from a side street, or to a construction worker approaching a driver in a road construction site. Two groups of nine young, healthy subjects were used. White, blue, green, red, fluorescent red, fluorescent yellow-green, yellow, fluorescent yellow, orange, and fluorescent orange were presented at peripheral angles to the right of the line of sight. The targets were presented at a radial distance of 30 m (100 ft) from the front bumper of the car at the selected peripheral angle. The subjects were seated in a stationary car and the targets were visible for 2 sec. Each subject provided a total of 180 observations. The results of this study indicate that the fluorescent color targets (especially the fluorescent yellow-green) were considerably better-detected peripherally than their nonfluorescent counterparts. Furthermore, for some peripheral angles fluorescent yellow-green was among the top three best-recognized colors. On the basis of the results of this study, it may be concluded tentatively that to maximize daytime conspicuity for peripheral detection and recognition, highly conspicuous fluorescent colors such as fluorescent yellow-green, along with a fairly large target size, should be selected. It appears that however conspicuous a color is alone, if the target is too small for the visual angle subtended, the color will not be well detected or recognized, especially at larger peripheral viewing angles.

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Hussain, Altaf, and Said M. Easa. "Reliability Analysis of Left-Turn Sight Distance at Signalized Intersections." Journal of Transportation Engineering 142, no. 3 (March 2016): 04015048. http://dx.doi.org/10.1061/(asce)te.1943-5436.0000824.

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Son, Young-Tae, Sang-Gu Kim, and Jin-Kak Lee. "Methodology to Calculate Sight Distance Available to Drivers at Skewed Intersections." Transportation Research Record: Journal of the Transportation Research Board 1796, no. 1 (January 2002): 41–47. http://dx.doi.org/10.3141/1796-05.

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Kumara, S. S. P., and H. C. Chin. "Application of Poisson Underreporting Model to Examine Crash Frequencies at Signalized Three-Legged Intersections." Transportation Research Record: Journal of the Transportation Research Board 1908, no. 1 (January 2005): 46–50. http://dx.doi.org/10.1177/0361198105190800106.

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Before effective remedial treatments can be implemented at hazardous intersections, it is often necessary to identify the causal factors affecting accident frequency. However, a problem often encountered in safety studies is the underreporting of accidents. This biased reporting may affect the selection of the parsimonious model. This study analyzes the factors affecting road accident frequency at three-legged signalized intersection approaches in Singapore, with special emphasis to underreporting. The annual accidents at 104 three-legged signalized intersections are modeled as the sum of observed Poisson outcome of accident reports. The reporting mechanism is introduced as a probit equation. The model shows that several geometric, traffic, and traffic control factors significantly affected the accident occurrence. The total approach volumes, left-turn volumes, existence of unprotected left-turn slip roads, number of signal phases per cycle, use of permissive right-turning phase, and sites with sight distances less than 100 m or greater than 300 m appear to increase accident occurrence. However, the presence of right-turn channelization, provision of an acceleration section for left turning, existence of a surveillance camera, availability of median railings, and presence of an approach gradient greater than +5% may reduce the occurrence of intersection approach accidents. Moreover, the study shows that the reporting rate may drop because current law enforcement requires that only injury accidents and accidents at intersections in a residential area be reported.

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BASSAN, Shy. "Empirical modeling of the relationship between decision sight distance and stopping sight distance based on AASHTO." Archives of Transport 4, no. 48 (December 31, 2018): 7–25. http://dx.doi.org/10.5604/01.3001.0012.8362.

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The paper introduces implementation of highways' stopping sight distance (SSD) and decision sight distance (DSD) based on AASHTO modeling assumptions. SSD characterizes the necessary distance for highway vehicles to stop safely in front from an obstacle. SSD is a function of vehicle speed, perception reaction time, deceleration rate, and grade based on AASHTO and most highway design international guidelines. The deceleration rate which is assumed constant (3.4 m/sec2) based on AASHTO 2011 is generally controlled by the friction coefficient depending on the road surface conditions. A driver's demanded deceleration rate may not exceed the range of friction coefficient according to various pavement conditions. Although SSD is generally sufficient to allow skilled and alert drivers to the stop their vehicles under regular situations, this distance is insufficient when information is difficult to comprehend. A DSD should be provided in highways geometric design when the driver is required to detect an unexpected or difficult to perceive information source. Interchanges (specifically exit ramps) and intersections, and required changing in driver direction of travel, changes in the basic cross section such as toll plaza, lane drop, are typical scenarios where driver needs DSD in the safety manner. The introduction of the two sight distance types (SSD and DSD) is a perquisite for empirical modeling of the relationship between DSD and SSD. The modeling refers to DSD for rural highways, suburban roads, and urban roads based on AASHTO models. Specifically the paper covers DSD three avoidance maneuver types of stopping (types A, A1, B) and three maneuver types of speed, path, and direction changing (types C,D, E) for the three roadway categories. The major parameters that control these avoidance types are pre-maneuver times, and pre-maneuver plus maneuver times. The empirical relationship proposed in this study simplifies the process of evaluating the decision sight distance based on stopping sight distance record, based on AASHTO models, without the need of strenuous estimation of the DSD model maneuver and deceleration parameters. Such a simplified correlation has not been found in the literature except a rough approximation documented in the British highway design guidelines.

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Dabbour, Essam, and Said Easa. "Sight-Distance Requirements for Left-Turning Vehicles at Two-Way Stop-Controlled Intersections." Journal of Transportation Engineering, Part A: Systems 143, no. 1 (January 2017): 04016004. http://dx.doi.org/10.1061/jtepbs.0000018.

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Harwood, Douglas W., John M. Mason, and Robert E. Brydia. "Design policies for sight distance at stop-controlled intersections based on gap acceptance." Transportation Research Part A: Policy and Practice 33, no. 3-4 (April 1999): 199–216. http://dx.doi.org/10.1016/s0965-8564(98)00040-8.

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Liu, Zhong Bo, and Zhao Sheng Yang. "Traffic Control Performance Evaluation at Road Intersections: A Case Study in the City of Changchun." Applied Mechanics and Materials 209-211 (October 2012): 1021–24. http://dx.doi.org/10.4028/www.scientific.net/amm.209-211.1021.

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According to the conditions of traffic flow and geometric characteristics of road intersections, a novel method is proposed to determine the sight distance triangle with the consideration of crossing intervals and traffic volume on the secondary road. Then the control mode is suggested for general plane intersections. In final, a simulation example in the city of Changchun is used to verify the effectiveness and performance of this traffic control mode model.

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Yan, Xuedong, Essam Radwan, and Elizabeth Birriel. "Geometric Models to Calculate Left-Turn Sight Distance for Signalized Intersections on Horizontal Curves." Journal of Transportation Engineering 132, no. 9 (September 2006): 683–90. http://dx.doi.org/10.1061/(asce)0733-947x(2006)132:9(683).

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Journal articles on the topic 'Intersection sight distance'

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