Improvements and New Concepts for Traffic Control in Work Zones. Volume 1. Four-Lane Divided Highways.

Nine case 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 vs. a crossover with two-lane, two way traffic operations (TLTWO). The following variables were studied: (1) worker productivity, (2) job duration, (3) concentration costs, (4) traffic control device costs, (5) highway user costs, (6) accidents, (7) conflicts, and (8) capacity.