OPTIMUM LENGTH OF TWO-LANE TWO-WAY NO-PASSING TRAFFIC OPERATION IN CONSTRUCTION AND MAINTENANCE ZONES ON RURAL FOUR-LANE DIVIDED HIGHWAYS

One method of traffic control in construction and maintenance (CM) zones on rural four-lane divided highways is to close one of the roadways for CM work and to divert traffic from it across the median to the other roadway, which is signed and marked for two-lane two-way no-passing traffic operation. The objective of this study was to determine the optimum length of the two-way operation. An equation was developed for the sum of the increase in road user costs due to the two-way operation and the cost of traffic control as a function of this length. Calculus was then used to derive the optimum length that would minimize the sum of traffic control and additional road user costs. The equation derived for optimum length can be used in the planning and design of crossover-type traffic control systems for CM zones on rural four-lane divided highways. (Author)