Nine field studies were conducted on four-lane divided highways in Texas and Oklahoma to evaluate two alternative traffic control approaches: single-lane closure in one direction versus a crossover with two-lane, two-way traffic operations (TLTWO). The variables studied were: worker productivity, job duration, construction costs, traffic control device costs, highway-user costs, accidents, conflicts, and capacity. Worker productivity was measured indirectly from job duration and construction costs. Because of limited data, it was not possible to identify the conditions under which one traffic control alternative offers costs savings over the other. Highway-user costs for each study site were calculated using a modified version of a work-zone queue and user-costs evaluation model. Graphs and tables show the relationships between hourly traffic volumes and road-user costs for the sites studied.(A).
Abstract