Perris Valley Commuter Rail


Ames converted an old rail system into a mass transit commuter line that connects downtown Perris to downtown Riverside along I-215 for California’s Metrolink.

Local and federal governments and agencies, the business community, and county residents collaborated for more than a decade to reach an agreement for the expansion. The biggest hurdle to project approval was concern for the environmentally and culturally sensitive areas within the project site. These include habitat for several species of endangered birds and Native American cultural resources. To ensure that these assets were protected, Ames field crews coordinated extensively with the project’s special inspectors and received valuable support from the Ames environmental team.

Construction included double-tracking approximately 24 miles of new and upgraded track; building four new stations and parking areas; improving 17 rail crossings; and installing infrastructure, ballast, drainage, and communications systems. The project scope also included grading and rock excavation, concrete structures, and the installation of two railroad bridges for the single rail track alignment.

The completed extension is part of the Metrolink’s Positive Train Control system, which provides state-of-the-art protection against train collisions.

Markets: Railroad, Mass Transit

Location: Riverside, California

Client: Riverside County Transportation Commission

Completion: October 2017


  • Constructed four train stations and a layover facility for Metrolink operations
  • Installed two railroad bridges


  • 460,670 cubic yards of earthwork, including more than 2,000 cubic yards of rock excavation