Estimation of Freeway Work Zone Capacity Using Simulation and Field Data

The objective of this research was to develop analytical models and procedures for estimating the capacity of a freeway work zone considering various geometric, traffic, and work zone related parameters. The study was conducted in two stages: simulation-based modeling, and field data collection. In the first stage, CORSIM (Version 5.1) was used to develop a comprehensive database for various work zone scenarios. Analytical models were developed to predict work zone capacity based on these simulated data and previous literature findings, considering three work zone configurations: 2-to-1, 3-to-2, and 3-to-1 lane closures. In the second stage, field data were collected at a freeway work zone to evaluate and refine the analytical models developed. Data were collected at the freeway work zone site during 15 evening peak periods, which included left- and right-lane closures, as well as rainy weather conditions. The observed capacities were compared to those predicted by the new analytical models as well as those estimated by the HCM 2000. It was concluded that the analytical models developed predicted within one percent the capacity of the study work zone.