Estimation of Freeway Work Zone Capacity Through 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 by 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 on the basis of these simulated data and previous literature findings considering three work zone configurations: two-to-one, three-to-two, and three-to-one lane closures. In the second stage, Held 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 with those predicted by the new analytical models as well as to those estimated by the Highway Capacity Manual 2000. It was concluded that the analytical models developed predicted within 1% the capacity of the study work zone.