Traffic Operations and Management

The goal of this project was to design, implement, and validate a computerized Glare Meter Tool that could be used in the field to assess the level of glare from headlights of opposing vehicles in a variety of situations, without relying on subjective reports of observers. Both disability glare and discomfort glare were addressed. The net result is an instrument that is capable of acquiring an image of a scene with glare, then analyzing the image to output a number on the standard, widely-used De Boer Rating Scale for Evaluation of Discomfort Glare, and also an equivalent veiling luminance...

Approaches for evaluating the quality of bicycling have become increasingly important for planning bicycle infrastructure improvements. Mekuria, Furth, and Nixon’s (2012) “Level of Traffic Stress” (LTS) approach, which requires minimal data inputs and produces a simple and intuitive output, has emerged as a widely-used framework for identifying streets that are “low-stress” for cyclists. The LTS framework is based on a hierarchy of characteristics, largely related to traffic speed and roadway layout, that are presumed to cause higher or lower levels of stress. Despite the apparent...

From an operation viewpoint, traffic breakdown (from free-flow) was defined as when the average speed of traffic drops below a certain threshold. It is known that traffic breakdown is a stochastic phenomenon which can happen even when the traffic flow is below the capacity. The capacity has many definitions, such as that in HCM or the average of maximum daily flow. This study investigates the probability of breakdown at certain locations of freeway. The motivation is to find a practical capacity for each freeway section for active traffic control/operation purposes, which could be...

This report presents the results of TO 5302, Extracting More Information from the Existing Freeway Traffic Monitoring Infrastructure. This report represents significant advances in the PATH sponsored research into vehicle reidentification from conventional loop detectors, first by extending the methodology across major merge and diverge freeway sections. Second, it extends the methodology to single loop detectors. The report also extends the understanding of traffic phenomena impacting both traffic flow and the performance of the reidentification algorithms. It examines the impacts of lane...