SPR 20-597: Estimate Travel Time Savings for Transportation Improvement Projects

This Research Program for the period July 1, 2018 to June 30, 2020 is submitted in compliance with the provisions of Section 307 of Title 23, United States Code, and describes programs and operations for planning activities in the Kentucky Transportation Cabinet (KYTC) and the Kentucky Cooperative Transportation Research Program (KCTRP). This program modifies and updates such programs and is specifically intended to reflect the needs of the Kentucky Transportation Cabinet. It is fully expected that products from this program will also have national applications. The University of Kentucky Transportation Center is the main research group for the the Kentucky Transportation Cabinet. The SPR grant is the funding the is supplied each year for the many topics the Center is asked to research for KYTC The KCTRP is concerned with the development and conduct of a comprehensive research program in cooperation with the U.S. Department of Transportation, Federal Highway Administration (FHWA). In addition to research developed in cooperation with FHWA, the KCTRP may perform other services for the KYTC on a nonparticipating basis. The scope of these services could include activities such as research studies and special investigations of various engineering and operation activities. The Research Program and Implementation Advisory Committee (RPIAC), headed by the State Highway Engineer and coordinated through the Research Coordinator, will give direction to the research program. PROBLEM STATEMENT Travel time savings is one of inputs to the SHIFT benefit-cost measure. It is the difference in travel times before and after an improvement project over a 10-year period. Currently, travel demand models are used to estimate travel time savings for major improvement projects. For projects with smaller scale, empirical equations depicting relationship between travel time index and volume-toservice flow ratio have been used. These equations are developed based on data from count stations that are limited in geographic coverage. We propose to use the speed data to calibrate and validate models for capacity and travel time estimation for Kentucky highways. The models should be sensitive enough to capture the impact of highway improvement projects at various scales and incorporate the latest methodologies. RESEARCH OBJECTIVES The goal of this study is to update the methods used in SHIFT 2020 for travel time savings estimation. Existing tools such as the VSF calculator and the adapted HERS speed model will be further calibrated and validated. Sensitivity analysis will be performed to evaluate the fitness of the models for project evaluation, especially for smaller projects. The expected product would be a tool that produces estimated travel time savings based on proposed highway improvement.