Caltrans eliminates several interchange designs; RCTC, cities move forward with Joshua Palmer realignment as preferred Highland Springs/I‑10 option

During a June 17 presentation to the Beaumont City Council, RCTC project managers and their consultants updated the council on the I‑10 Highland Springs Avenue interchange study and said Caltrans has ruled out previously studied diverging diamond and hook‑ramp options because of operational, safety and right‑of‑way concerns.

What remains: The consultant team described Alternative 5, a Joshua Palmer Way realignment that keeps eastbound ramps in their existing locations but realigns and couplets Joshua Palmer Way north of restaurants and the gas station so traffic movements and signal phasing will change. Consultants said Alternative 5 meets the project’s purpose and need without the excessive right‑of‑way acquisition and construction costs associated with previous alternatives. The team said they will continue technical and environmental studies, and that Public Meetings and environmental circulation will proceed as the Project Approval/Environmental Document phase continues.

Caltrans role and prior alternatives removed: Darren Johnson (Mark Thomas) said Caltrans rejected the diverging diamond interchange designs in early 2024 because the alternatives failed the project’s purpose and need, would have required the closure or acquisition of multiple private driveways and the Highland fuel station, and delivered poor long‑term operational performance. In 2025 Caltrans also declined to approve the hook ramp alternatives (2A/2B), citing geometric and safety shortcomings, especially for the eastbound off‑ramp and hook‑on ramp radii, and concerns that the designs required nonstandard features Caltrans would not accept. The team said Caltrans requested new alternatives in late 2024, and Alternative 5 was developed in response.

Traffic operations and signals: Council members asked whether traffic signals farther north (Apex and Ramsey) would be included; project staff confirmed a signal near Apex and Ramsey is under consideration and likely to be included. Consultants said Alternative 5 improves both Highland Springs and Joshua Palmer traffic flow via better signal phasing and fewer closely spaced intersections, and increases operational capacity compared with the removed alternatives.

Costs and schedule: The team estimated that a full rebuild/widening option previously proposed by Caltrans could have cost roughly $150 million and required full right‑of‑way acquisition of existing commercial properties. The consultants said Alternative 5 should be significantly less expensive than the removed options, although a formal cost estimate was not provided at the council meeting. The PA/ED phase began in October 2022; the team said right‑of‑way acquisition and final design could begin in 2027 with construction after design and funding are secured.

Speakers/attribution: David Lewis (RCTC capital project manager), Darren Johnson (Mark Thomas project engineer) and Jason Pack (traffic engineer) presented the technical update and answered council questions.

Ending: The project team said it will continue engineering and environmental work on Alternative 5 and coordinate with Caltrans. The team expects to remove the hook ramp alternatives formally at the next PED coordination meeting.

Speakers quoted: Darren Johnson (Mark Thomas), David Lewis (RCTC).