Optimal work zone lengths for two-lane highways

Highway pavement maintenance is very expensive not only in terms of costs to the responsible agencies, but also in terms of disruptive delays to users. Construction and maintenance activities on two-lane, two-way highways often require the closure of one travel lane. Longer work zones and the longer cycle times associated with such zones tend to increase the user delay costs. Maintenance work can be performed more efficiently, i.e., with fewer repeated setups, in longer zones. A mathematical model is developed to optimize the work zone length and traffic control on two-lane, two-way highways where one lane at a time is closed. The objective is to minimize the total cost, including the agency cost and user delay cost. Unbalanced traffic flows in both directions are considered. The optimized variables (e.g., work zone length and cycle time) and the sensitivity results generated from a numerical example are presented in this study.