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Highway capacity, Traffic flow, Transit operations -- Evaluation -- Methodology, Traffic estimation, Roadway reallocation -- Analysis


The traditional process of identifying corridors for road diet improvements involves selecting potential corridors (mostly based on identifying fourlane roads) and conducting a traffic impact analysis of proposed changes on a selected roadway before implementing changes. The evaluation of roadway reallocation projects should include the analysis of traffic volumes, level of service, speeds, queue lengths and bus operations. There are tools and equipment to evaluate effectively traffic volumes and level of service changes in before-and-after studies. However, the detailed evaluation of speed and queue length distributions along a segment are significantly more cumbersome. In addition, the exhaustive evaluation of bus operations requires detailed data and specific tools and cannot be readily accomplished with field measurements or conventional level of service studies. This research presents a general methodology for the detailed evaluation of transit operations and speed and queue length distributions along roadway reallocation projects. The strategy and methodology is based on the utilization of high-resolution transit datasets. The focus of this research is on the development of a practical, general and theoretically sound methodology that can be applied to future roadway reallocation projects and applicable in a wide range of traffic conditions and locations. The methodology proposed in this research was applied successfully to two separate road diets in Portland, OR.


This is a final report, NITC-RR-887, from the NITC program of TREC at Portland State University, and can be found online at:

The Project Brief associated with this report can be found at:


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