Regional Prioritization Of Corridors For Traffic Signal Retiming

Abstract

Every three to four years, the North Central Texas Council of Governments (NCTCOG) funds signal retiming projects to improve air quality in the Dallas-Fort Worth region. As sufficient funds are not available to retime all signals in the region at the same time, the retiming must be completed in phases. To optimize the impact of the retiming projects, the candidate corridors must be rank ordered or prioritized. NCTCOG applies a ranking model, which uses variables like delay, number of stops and system type, a dummy variable based on centralized control. The weighting for each factor is based on expert input from a group forum using direct allocation of the percentage weighting. This thesis proposes a new, improved methodology based on signal retiming benefits rather than the severity of existing traffic conditions. Benefits are estimated from the before and after studies conducted along the corridors where retiming is executed recently. Benefits in delay, fuel consumption and emissions are to be modeled in terms of various physical characteristics and traffic flow characteristics of the corridors. This model helps in estimating benefits beforehand and prioritizing the retiming projects based on these benefits. Appropriate conversion rates are identified to convert all benefits into dollars.