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This report describes the collection, analysis, and modeling of crash and roadway211 data for intersections on rural roads in California and Michigan for the years 211 1993-1995. Three classes of intersections are considered: (1) ...
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This report describes the collection, analysis, and modeling of crash and roadway211 data for intersections on rural roads in California and Michigan for the years 211 1993-1995. Three classes of intersections are considered: (1) three-legged 211 intersections with major road four-lane and minor leg two-lane stop-controlled, 211 (2) four-legged intersections with major road four-lane and minor legs two-lane 211 stop-controlled, and (3) signalized intersections with both major and minor roads 211 two-lane.
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According to the National Highway Safety Administration, one out of eight fatalities occurring at intersections is a pedestrian. An intelligent, real-time system capable of predicting situations leading to accidents or near misses...
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According to the National Highway Safety Administration, one out of eight fatalities occurring at intersections is a pedestrian. An intelligent, real-time system capable of predicting situations leading to accidents or near misses will be very useful to improve the safety of pedestrians as well as vehicles. This project investigates the prediction of such situations using current traffic conditions and computer vision techniques. An intelligent system may gather and analyze such data in a scene (e.g., vehicle and pedestrian positions, trajectories, velocities, etc.) and provide necessary warnings. The current work focuses on the monitoring aspect of the project. Certain solutions are proposed and issues with the current implementation are highlighted. The cost of the proposed system is low and certain operational characteristics are presented.
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The purpose of this report is to document the development of the Intersection Design Alternative Tool (IDAT) developed for the Kentucky Transportation Cabinet. IDAT provides an automated objective design and evaluation approach of...
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The purpose of this report is to document the development of the Intersection Design Alternative Tool (IDAT) developed for the Kentucky Transportation Cabinet. IDAT provides an automated objective design and evaluation approach of 14 alternative intersection designs to assist in the conceptual design of at-grade intersections. The tool evaluates intersection operations, safety performance, bicycle/pedestrian accommodation and has the ability to assist access management implementation.
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Multiple-lane approaches (MLAs) controlled by stop signs are becoming increasingly common in Nebraska. Installation of MLAs occurs when a single approach lane can no longer adequately serve the minor road traffic volume, and a sig...
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Multiple-lane approaches (MLAs) controlled by stop signs are becoming increasingly common in Nebraska. Installation of MLAs occurs when a single approach lane can no longer adequately serve the minor road traffic volume, and a signal is unwarranted because Manual of Uniform Traffic Control Devices (MUTCD) warrants are not satisfied (7, FHWA, 2003). A common example of a location at which MLA stop-controlled intersections can occur in Nebraska is the rural intersection of two state or federal highways. Forty such intersections in Nebraska were available for study in this research. Additionally, such intersections are often located in suburban areas of Nebraska municipalities where the local-collector network of a residential development connects to an arterial roadway. The objective of this research was to investigate driver safety and behavior at two-way stop-controlled MLA intersections. The reason for the investigation is to gain a better understanding of potential sight distance limitations due to side-by-side stopped vehicles at stop signs, as described earlier.
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This document is intended to be a guide for planning-level decisions concerning safety issues and subsequent potential improvements at rural expressway intersections. It is NOT a design guide. It simply presents the gamut of safet...
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This document is intended to be a guide for planning-level decisions concerning safety issues and subsequent potential improvements at rural expressway intersections. It is NOT a design guide. It simply presents the gamut of safety treatment options and available strategies that have been employed in an attempt to reduce the number and severity of collisions at unsignalized rural expressway intersections. This document should only be used as a tool for considering safety treatment options at rural expressway intersections. It is meant to aid transportation agency management in selecting the most appropriate rural expressway treatment to address the particular safety issue they are facing. This document is a quick reference companion to the Rural Expressway Intersection Safety Toolbox. More details on each strategy can be found within the contents of that document.
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The most common type of intersection improvement considered by many state DOTs issignalization. The Washington State Department of Transportation (WSDOT) uses a system called the Intersection Priority Array, which was originally d...
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The most common type of intersection improvement considered by many state DOTs issignalization. The Washington State Department of Transportation (WSDOT) uses a system called the Intersection Priority Array, which was originally developped by Ching (Ching, 1979). This system provides a tool for objectively considering numerous intersections. Although the system is useful, it only addresses the need for and relative priority of a signal. It does not address other actions that may improve the safety and efficiency of the intersection. The goal of this research project was to develop a system for analyzing the need for left-and/or right-turn lane improvements to an intersection and prioritizing the severity of that need. To be effective the system needed to be based on engineering studies; objective and logical; easy to use; able to use easily obtainable data; able to adapt to changing standards; and accepted by operation engineers, management, and planners.
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The primary objective of this study was to develop safety indices to allow engineers, planners, and other practitioners to proactively prioritize intersection crosswalks and intersection approaches with respect to pedestrian and b...
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The primary objective of this study was to develop safety indices to allow engineers, planners, and other practitioners to proactively prioritize intersection crosswalks and intersection approaches with respect to pedestrian and bicycle safety. The study involved collecting data on pedestrian and bicycle crashes, conflicts, avoidance maneuvers, and subjective ratings of intersection video clips by pedestrian and bicycle experts. There were a total of 68 intersection crosswalks selected for the pedestrian analysis from the cities of Philadelphia, PA; San Jose, CA; and Miami-Dade County, FL. The bicycle analysis included 67 intersection approaches from Gainesville, FL; Philadelphia, PA; and Portland and Eugene, OR. Prioritization models were developed based on expert safety ratings and behavioral data. Indicative variables included in the pedestrian safety index model included type of intersection control (signal or stop sign), number of through lanes, 85th percentile vehicle speed, main street traffic volume, and area type. Indicative variables in the bicycle safety models (for through, right-turn, and left-turn bike movements) included various combinations of: presence of bicycle lane, main and cross street traffic volumes, number of through lanes, presence of on-street parking, main street speed limit, presence of traffic signal, number of turn lanes, and others. Through a user-friendly guide, practitioners will be able to use the safety indices to identify which crosswalks and intersection approaches have the highest priority for in-depth pedestrian and bicycle safety evaluations and subsequently use other tools to identify and address potential safety problems.
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Confirmation lights were deployed at two intersections in Overland Park, Kansas. Traffic was observed at the treatment sites, nearby signalized intersections (spillover), and control sites. Traffic was recorded before deployment, ...
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Confirmation lights were deployed at two intersections in Overland Park, Kansas. Traffic was observed at the treatment sites, nearby signalized intersections (spillover), and control sites. Traffic was recorded before deployment, 1 month after, and 3 months after deployment. A total of 14 intersections were recorded during the morning peak hours (7 a.m. to 9 a.m.) and the afternoon peak hours (4 p.m. to 6 p.m.) for a total of 583 hours of traffic video.
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For intersections with a permissive or protected-permissive left-turn mode, pedestrians cross during the permissive period. This operation requires the left-turn driver to yield to both opposing vehicles and pedestrians, prior to ...
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For intersections with a permissive or protected-permissive left-turn mode, pedestrians cross during the permissive period. This operation requires the left-turn driver to yield to both opposing vehicles and pedestrians, prior to accepting a gap and completing the turn. Pedestrian crash risks are increased in these complicated driving conditions because left-turn drivers sometimes fail to yield to pedestrians. This document summarizes the research conducted and the conclusions reached during the development of guidelines for pedestrian safety treatments at signalized intersections. The guidelines are focused on treatments that alleviate conflicts between left-turning vehicles and pedestrians. One treatment addressed in the document is the use of protected or protected-permissive left-turn operation. The guidelines are based on consideration of pedestrian safety and vehicle operation. These considerations include the road-user costs associated with pedestrian-vehicle crashes and vehicle delay. The guidelines were incorporated in the Traffic Signal Operations Handbook. The guidelines were also incorporated into a spreadsheet that was developed to accompany the Handbook. The Handbook was previously developed for Project 0-5629. It provides guidelines for timing traffic control signals at intersections that operate in isolation or as part of a coordinated signal system.
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