Transportation Study Guidelines

These guidelines describe the transportation analysis requirements for land development, roadway projects, and specific plans within Diamond Bar. Guidelines are provided for evaluating a project’s environmental transportation impacts and effects on the local transportation system. They provide guidance on how to prepare transportation studies in the City in conformance with all applicable City and State regulations.

Background Information

Senate Bill 743, signed by the Governor in 2013, has changed the way transportation impacts are identified. Specifically, the legislation directed the Office of Planning and Research (OPR) to look at different metrics for identifying transportation as a California Environmental Quality Act (CEQA) impact. The Final OPR guidelines were released in December 2018 and identified Vehicle Miles Traveled (VMT) as the preferred metric moving forward. The Natural Resources Agency completed the rule making

process to modify the CEQA guidelines in December of 2018. The CEQA Guidelines identify that, by July of 2020 all lead agencies must use VMT as the new transportation metric for identifying impacts for land use project.

  1. Public Works Engineering


    Phone: (909) 839-7040