I-15 Express Lanes Project Southern Extension
Status: Pre-Construction
Location: Interstate 15 between El Cerrito Road in Corona and State Route 74 (Central Avenue) in Lake Elsinore
Construction: Anticipated to begin in 2028 and open in 2030
Investment: $985 million
Location: Interstate 15 between El Cerrito Road in Corona and State Route 74 (Central Avenue) in Lake Elsinore
Construction: Anticipated to begin in 2028 and open in 2030
Investment: $985 million (estimate for pre-construction, design, construction)
OVERVIEW
The Riverside County Transportation Commission (RCTC), in partnership with the California Department of Transportation, received environmental approval for the Interstate 15 Express Lanes Project Southern Extension in December 2025. In May 2026, RCTC awarded the project’s Progressive Design-Build (PDB), marking the transition into design and pre-construction.
The project will improve and manage traffic operations, reduce congestion, and enhance travel times along the corridor by extending the I-15 Express Lanes south approximately 15.8 miles from El Cerrito Road in Corona, through Temescal Valley, to State Route 74 (Central Avenue) in Lake Elsinore. Two toll lanes will be added in both directions within the I-15 median to accommodate increasing traffic volumes in southwest Riverside County. The project will also add auxiliary lanes to southbound I-15 between the Nichols Road on-ramp and the Main Street off-ramp in Lake Elsinore.
PROJECT BENEFITS
The project will:
- Improve traffic operations and travel times
- Expand travel choice through carpooling and mass transit options
- Increase travel time reliability
- Better manage long-term traffic congestion
- Expand and strengthen compatibility with the region’s growing Express Lanes network
Other project features include widening up to 15 bridges, constructing multiple express lane entrance and exit points, and installing noise barriers, retaining walls, drainage systems, and electronic toll collection equipment, and signage.
The I-15 Express Lanes Project Southern Extension received environmental approval in December 2025. In May 2026, RCTC awarded a Progressive Design-Build (PDB) Phase 1 contract thatincludes preliminary design along with validating the project scope and negotiating the cost for Phase 2. Phase 2 will include final design and construction.
The total project cost is estimated at $985 million. Based on available funding, the project could begin construction in 2028 and open to traffic by 2030. RCTC is exploring funding options for construction that may include a combination of federal, state, local, and toll revenue supported financing sources to support construction. The project may also be constructed in segments, subject to funding availability.
RCTC has chosen the innovative Progressive Design-Build (PDB) delivery model for this project to allow RCTC and the contractor to work together in optimizing design options and costs to expedite overall project delivery by constructing the project as funding becomes available. The PDB delivery method fosters collaboration from the earliest stages of project development, allowing the team to refine design solutions, manage risks, and optimize costs before construction begins.
The I-15 Express Lanes Project Southern Extension is the first project on California’s state highway system to utilize the PDB delivery model.
- 2007: Caltrans approves 45-mile study of I-15 corridor, Route 60 to Murrieta
- 2008: RCTC and Caltrans begin planning studies
- 2009: RCTC receives tolling authority on I-15 from San Bernardino County Line to San Diego County Line
- 2014: RCTC and Caltrans begin studies on I-15 from Route 60 to Cajalco Road
- 2016: RCTC and Caltrans approve environmental document for I-15 Express Lanes
- 2018: RCTC secures funding for I-15 Express Lanes Project Southern Extension (ELPSE) preliminary engineering and environmental studies
- 2018: Construction begins for I-15 Express Lanes Project
- 2019: Preliminary engineering and environmental studies begin for I-15 ELPSE to support Environmental Impact Report/Environmental Assessment
- October 21- November 22, 2019: 30-day public scoping period
- November 12-14, 2019: Public scoping meetings, Temescal Valley, Corona, Lake Elsinore
- October 2024: RCTC releases Draft Environmental Impact Report and Environmental Assessment (EIR/EA) for public review and comment, and hosts three open house public hearings
- December 2025: The I-15 Express Lanes Project Southern Extension receives environmental approval
- May 2026: RCTC awards the Progressive Design-Build Phase 1 Agreements, initiating the pre-construction phase with Parsons as Project Construction Manager and SC Constructors, a Joint Venture, as the design-builder
- 2026-2027: Pre-construction activities include collaborative design development, cost estimating, risk evaluation, and constructability reviews under the Progressive Design-Build delivery method
- 2028 (anticipated): Construction begins
- 2030 (anticipated): I-15 Express Lanes Southern Extension open to traffic
For questions/comments about this project, please respond below.
RCTC released the Draft Environmental Impact Report and Environmental Assessment (EIR/EA) for public review and comment on October 9, 2024. The preliminary engineering and environmental phase was completed in 2025.
RCTC is utilizing a progressive design-build method to expedite the delivery of the project. Construction could begin in 2028, depending on funding availability. The total project cost is estimated to be $985 million. RCTC is exploring funding options for construction that may include a combination of federal, state, local, and toll sources.
Project information boards and videos from the public meetings are available below:
Click on the image above to download the project boards
- 2007: Caltrans approves 45-mile study of I-15 corridor, Route 60 to Murrieta
- 2008: RCTC and Caltrans begin planning studies
- 2009: RCTC receives tolling authority on I-15 from San Bernardino County Line to San Diego County Line
- 2014: RCTC and Caltrans begin studies on I-15 from Route 60 to Cajalco Road
- 2016: RCTC and Caltrans approve environmental document for I-15 Express Lanes
- 2018: RCTC secures funding for I-15 Express Lanes Project Southern Extension (ELPSE) preliminary engineering and environmental studies
- 2018: Construction begins for I-15 Express Lanes Project
- 2019: Preliminary engineering and environmental studies begin for I-15 ELPSE to support Environmental Impact Report/Environmental Assessment
- October 21- November 22, 2019: 30-day public scoping period
- November 12-14, 2019: Public scoping meetings, Temescal Valley, Corona, Lake Elsinore
- 2024: RCTC releases Draft Environmental Impact Report and Environmental Assessment (EIR/EA) for public review and comment, and hosts three open house public hearings
For questions/comments about this project, please respond below.
The I-15 Express Lanes Project Southern Extension Progressive Design-Build RFQ has been issued and is due on April 8, 2025.
For more information, visit PlanetBids here.