Evaluation of Operational Effects of Freeway Reconstruction Activities

To better evaluate the operational effects of freeway maintenance/ reconstruction activities, a new methodology has been developed. This methodology takes traffic demand, freeway geometry, and maintenance/ reconstruction plans as input and uses the modified FREQ simulation model, FREQ10PC, to quantitatively predict freeway performance under different maintenance/reconstruction plans. Then a comprehensive evaluation of these plans can be carried out based on the predicted measures of performance. This paper describes the new methodology, the FREQ model, its modification and verification, and a literature search and survey of experts on freeway capacities through work zones. Descriptions of two major applications of the methodology, on for the San Francisco-Oakland Bay Bridge and the other for Interstate 80 (I-80) northeast of that bridge, are provided. The Bay Bridge application was designed to assess the operational effects of different maintenance plans, and the I-80 application was used to evaluate the traffic impacts of different nighttime lane closure alternatives during reconstruction activities. The results reveal that operational effects are extremely sensitive to lane closure schedules and plans and to freeway design elements. The results also show that the new methodology is effective in evaluating operational effects of freeway maintenance/reconstruction activities.