Development of a Guideline for Work Zone Diversion Rate and Capacity Reduction

Status: Complete
Report Date: 03/31/2016

Summary:

One of the critical elements for an effective management of the delays at work zones is the capability to accurately estimate the traffic diversion rates resulting from the reduced capacity at a given site. This study developed a comprehensive guideline to estimate the traffic diversion rates and capacity reduction for work zones. The analysis of the traffic diversion patterns with data from past work zones in the metro freeway network resulted in a set of the diversion-estimation models that relate the diversion rates at entrance and exit ramps with the traffic delay on a freeway and alternative route travel times. The interrelationship between diversion and work zone delays has led to the development of an iterative process, where a freeway simulation model interacts with the diversion-estimation models until a convergence is achieved between diversion and resulting freeway delays. Freeval is adopted in this study as the simulation tool for freeways. The test results of the iterative process with the work zone data showed promising results in determining both the diversion rates and freeway delays for a given work zone.