Optimizing work zones for two-lane highway maintenance projects

Highway maintenance is very expensive in terms of not only costs to the responsible agencies but also disruptive delays to users. Construction and maintenance activities on two-lane two-way highways often require the closure of one lane. During certain periods of a day, the user delay associated with lane closure may be quite intolerable to motorists. A numerical method is developed to optimize work-zone scheduling 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 maintenance, labor/equipment idle, and user-delay costs, considering traffic flows varying over time. The optimized variables (e.g., work-zone lengths and cycle times) and the sensitivity results generated from a numerical example are presented in this study.