The I-15 Express Lanes Project will be built along a 14.6-mile corridor of Interstate 15 in Riverside County, California between the Cajalco Road interchange near the city of Corona to just south of the SR 60 interchange near the San Bernardino/Riverside county line.  I-15 is a major north-south truck/passenger route that links Southern California to Los Angeles and Orange counties as well as to Las Vegas. I-15 is part of the National Highway System that links to major east-west limited access roads and arterials, including SR-91, SR-60, I-10, and SR-74.

The Project consists of the construction of one to two managed lanes in each direction primarily along the median of I-15 and includes retaining walls, storm water runoff treatment services, 11 bridge widenings, tie-ins to the existing travel lanes, an electronic toll collection system, a customer service center and a traffic management system. The Project is designed to improve congested traffic operations and travel times as compared to the I-15 general purpose lanes and expand travel choice as well as providing direct access to the express lanes that RCTC recently opened on SR-91.