PL 32, Measuring Congestion for SHIFT Implementation

This research aims to develop a framework for integrating speed data into traditional congestion performance measures. KTC will evaluate the current methodology and available data for congestion performance measures, and investigate ways to enhance the measure of congestion using speed data to be acquired in this study. This measure should accurately reflect peak period operating condition and offer a uniform scale that allows direct comparison of level of congestion among different types of facilities. The major components of the study are listed below. They are scoped based on discussion during the Congestion Workgroup meeting on December 15, 2017. " Data acquisition and processing o RFP and vendor/product selection with KYTC input o Perform data quality assessment including temporal and spatial accuracy as well as adequate coverage and resolution. o Network conflation o Aggregation to annual statistics " Develop an enhanced congestion performance measure o Review the state-of-the-practice on congestion performance measures at state DOTs, especially those that have integrated travel time data o Investigate how to set the "reference speed" for travel time based congestion measures such as travel time index (TTI). The goal is to ensure that the measure of congestion is on the same scale across all facility types. o Investigate the applicability of calculating a congestion measure using speed data for different sample pools based on its coverages. This analysis seeks to answer the question of how much data would be considered "enough" to produce a credible measure of congestion. o Investigate ways to measure congestion on ramps and provide a list of necessary data items to estimate the measure. This is to address the lack of data for ramps, even though interchanges are often congestion "hotspots". o Evaluate the consistency among potential performance measures, such as VSF, TTI, density, percent free flow travel time, level of service, etc. " Develop a procedure to incorporate speed data into congestion performance measures. This shall include a method to address situations beyond the applicability of speed data. " Develop a tool for calculating measure of congestions annually or biennially. The results of this study shall enable KYTC to systematically evaluate levels of congestion on all roads, as well as on projects submitted for funding consideration.