Location: Interstate 15 between Cajalco Road in Corona and State Route 74 (Central Avenue) in Lake Elsinore

Construction: Could begin as early as 2025

Investment: $550-600 million (estimate for pre-construction, design, construction)


The Riverside County Transportation Commission, in partnership with Caltrans, is conducting preliminary engineering and environmental studies to support an Environmental Impact Report and Environmental Assessment for the proposed Interstate 15 Express Lanes Project Southern Extension. RCTC is the local project sponsor.

The proposed project would add capacity by extending the I-15 Express Lanes, currently under construction, by an additional 14.5 miles. The proposed new segment would extend from Cajalco Road in Corona, through Temescal Valley, to State Route 74 (Central Avenue) in Lake Elsinore. The project proposes adding two tolled express lanes in both directions within the I-15 median to accommodate increasing traffic volumes in Riverside County.

Once built, the project would improve traffic operations and travel times, expand travel choice through carpooling and mass transit, increase travel time reliability, manage long-term traffic congestion, provide a cost-effective mobility solution, and expand and maintain compatibility with the regional express lanes network.

Other project features include widening up to 15 bridges, creating multiple express lane entrance and exit points, as well as building noise barriers, retaining walls, drainage systems, and electronic toll collection equipment and signs.

RCTC received $29 million in state funding in 2018 for the preliminary engineering and environmental studies, and work began for this phase of work in fall 2019. Public scoping meetings will be held in November 2019.

The environmental phase of work will take approximately five years, due to the complexity of the project corridor, which crosses multiple jurisdictions, widens up to 15 bridges, and may affect numerous waterways.

Pending project approval, RCTC expects to use a design-build approach to expedite the delivery of the project. Construction could begin as early as 2025, if RCTC is able to secure funding. The total project cost is estimated to be $550-600 million. RCTC is exploring funding options for construction that may include a combination of federal, state, local, and toll sources.

  • 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
  • 2022 (Anticipated): 45-day public review and comment period for Draft Environmental Document for Environmental Impact Report/Environmental Assessment
  • 2024 (Anticipated): Potential Final Environmental Document, pending approval

Environmental Documents

    • Record of Decision (Aug 2015), click here.
    • Federal Register Notice of Limitations on Claims for Judicial Review of Actions by the FHWA pursuant to 23 U.S.C 139 and other Federal agencies, click here.

Volume I - Chapters 1 - 2 and Chapters 4 - 7

Vol I Cover.pdf – 72.17 KB
1.0 Proposed Project.pdf – 5.30 MB
2.0 Project Alternatives.pdf – 56.48 MB
4.0 CEQA.pdf – 763.30 KB
5.0 Comments and Coordination.pdf – 349.48 KB
6.0 List of Preparers.pdf – 41.99 KB
7.0 Distribution List.pdf – 320.69 KB
Master TOC.pdf – 58.38 KB
Summary.pdf – 479.81 KB

Volume 1 - Chapter 3

Volume II (Appendicies A-I and Appendicies K-N)

Volume II (Appendix J-Supplemental Ch 5 Attachments)

App J Supplemental Ch 5 Attachments.pdf – 92.14 KB
Attachment J-1.pdf – 9.73 MB
Attachment J-2_1.pdf – 2.41 MB
Attachment J-2_10.pdf – 219.89 KB
Attachment J-2_11.pdf – 1.74 MB
Attachment J-2_12.pdf – 8.16 MB
Attachment J-2_13.pdf – 531.94 KB
Attachment J-2_14.pdf – 1.74 MB
Attachment J-2_2.pdf – 2.58 MB
Attachment J-2_3.pdf – 1.95 MB
Attachment J-2_4.pdf – 1.45 MB
Attachment J-2_5.pdf – 13.24 MB
Attachment J-2_6.pdf – 394.75 KB
Attachment J-2_7.pdf – 755.16 KB
Attachment J-2_8.pdf – 3.26 MB
Attachment J-2_9.pdf – 6.31 MB
Attachment J-3.pdf – 17.56 MB
Attachment J-4.pdf – 20.93 MB
Attachment J-5.pdf – 2.87 MB
Attachment J-6.pdf – 5.97 MB
Attachment J-7.pdf – 791.41 KB

Volume III

Vol III Cover.pdf – 64.50 KB
App O Parcel Acquisitions.pdf – 342.94 MB
App P Habitat Mitigation and Monitoring.pdf – 17.19 MB
App Q References.pdf – 73.07 KB
App R Index.pdf – 108.43 KB
App S RTC.pdf – 105.52 MB
App T MSHCP.pdf – 47.66 MB
App U MOA.pdf – 46.78 MB
App V RTC.pdf – 8.22 MB
App W BO.pdf – 662.15 KB

  1. Addendum to the Community Impact Assessment (January 2012; 21 MB)
  2. Air Quality Analysis (March 2012; 7 MB)
  3. Archaeological Evaluation Proposal (November 2007)
    Contact RCTC: Confidential Content
  4. Community Impact Assessment (June 2008; 150 MB)
  5. Draft Preliminary Drainage Report (March 2011; 37 MB)
  6. Draft Project Report (November 2012; Approved January 2013; 2 MB)

  7. Draft Relocation Impact Report (December 2011; 700 KB)
  8. Extended Phase I Survey Proposal (May 2007)
    Contact RCTC: Confidential Content
  9. Finding of Effect (November 2012)
    Contact RCTC: Confidential Content
  10. Hazardous Waste Initial Site Assessment (July 2011; 7 MB)
  11. Historic Property Survey Report (June 2012)
    Contact RCTC: Confidential Content
  12. Natural Environmental Study (July 2008; 146 MB)
    (Appendicices A-R) Jurisdictional Delineation Report (May 2007; revised February 2008):

  13. Noise Abatement Decision Report (April 2012; 19 MB)
  14. Noise Study Report (January 2012; 161 MB)
  15. Paleontological Resources Identification and Evaluation Report (March 2008; 494 MB)
  16. Preliminary Geotechnical Design Report for the Project Report and Environmental Document (March 2008; 43 MB)
  17. Preliminary Recommendations of Eligibility and Level of Effects Report (July 2008)
    Contact RCTC: Confidential Content
  18. Storm Water Data Report (October 2011; 11 MB)
  19. Summary of Floodplain Encroachment (September 2011; 145 MB) Includes: Location Hydraulic Studies
  20. Supplemental Extended Phase 1 Proposal (October 2007)
    Contact RCTC: Confidential Content
  21. Supplemental Paleontological Resources Identification and Evaluation Report (September 2011; 47 MB)
  22. Supplement to the Natural Environment Study (December 2011; 33 MB) Includes: Potential Impacts of Alternatives to Waters of the United States, Riparian Ecosystems, and Threatened and Endangered Species (October 2011) and Supplemental Jurisdiction Delineation Report (October 2011)
  23. Errata Memorandum for the Supplement to the Natural Environment Study (November 2012; 2 MB)
  24. Traffic Technical Report (February 2012; 23 MB)
  25. Visual Impact Assessment (August 2011; 19 MB)
  26. Water Quality Assessment Report (6 MB)

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