Good Practice Work Zone Management - California

The California Department of Transportation (Caltrans) minimizes disruption to the traveling public during construction or other planned activities necessary on the State Highway System (SHS). Caltrans uses innovative means to minimize work-related traffic delay and accelerate completion of highway work activities while taking necessary steps to maintain public and worker safety and the quality of the work being performed. To help accomplish this objective, Caltrans began requiring Transportation Management Plans (TMPs) in 2000 for all planned activities on the SHS. A TMP is a program of activities for alleviating or minimizing work-related traffic delays by the effective application of traditional traffic handling practices and an innovative combination of various strategies encompassing pubic awareness campaigns, motorist information, demand management, incident management, system management, construction methods and staging, and alternative route planning. TMP strategies also strive to reduce overall duration of work activities where appropriate. These strategies include: full facility closures, extended weekend closures, continuous weekday closures, and performance-based traffic handling specification, where appropriate.

During project initiation and planning, Caltrans reviews each project to determine which mitigation strategies will need to be deployed based on project conditions and the anticipated work zone safety and mobility impacts. The Department stipulates that motorists must not be delayed more than 30 minutes above normal recurring delay when work is being performed on the highway. Caltrans considers a delay of 30 minutes or longer to be a significant traffic impact.

Caltrans TMPs are categorized into three types based on project characteristics and projected delay: Blanket TMP, Minor TMP, and Major TMP. A Blanket TMP is a standard set of actions taken to minimize delay when performing maintenance activities or projects. Minor TMPs are used for improvement projects when minimal impacts are expected (e.g., night-time construction). Major TMPs are implemented for projects where significant traffic impacts are anticipated and multiple TMP strategies are required to manage impacts.

The implementation of TMPs in California has helped to significantly reduce delays in work zones. One example of the successful use of TMPs is from Caltrans District 7 on the I-10 Long-Life Pavement Project where the TMP helped reduce traffic demand by an estimated 57 percent, queue lengths to 2 miles from the originally projected 44 miles, and projected delays from an estimated 1,000,000 to 16,000 total vehicle hours of delay. For the I-15 Devore Pavement Reconstruction project, Caltrans compared construction options and the estimated delays that would result, and was able to minimize lane closures and the overall cost compared to other options for the I-15 project.