Traffic Capacity Through Work Zones on Urban Freeways

The report summarizes findings of capacity studies conducted at urban freeway maintenance and construction work zones in Houston and Dallas. Studies were conducted on 5-, 4-, and 3-lane freeway sections. The results indicate that the per lane capacities are affected by the number of lanes open during the roadwork. For example, the average capacity on a 3-lane section with 2 lanes open was 1500 vphpl; while the average capacity with 1 lane open was only 1130 vphpl. The report also illustrates how the data can be used to estimate the effects of the lane closures in terms of queue length, and thus can be applied to work scheduling.