Caltrans outlines technical approach, monitoring and safety steps at Regent's Slide on Highway 1; no reopening date

Caltrans officials described an ongoing, multi‑phase effort to clear the Regent’s Slide on Highway 1 and said they cannot yet give a reopening date.

At a June meeting of the Big Sur Byways advisory group, Caltrans District 5 construction staff described repeated slides above the main failure, use of remote equipment and a combination of geotechnical fixes intended to allow crews to excavate downward to the ocean. "The strategy was to minimize the excavation on the coast and try to get this slide cleared as quickly as possible," the Caltrans presenter said, describing a work plan that has repeatedly moved up and down the slope as conditions change.

Caltrans said crews have used remote‑controlled dozers and excavators, contractors’ "spider hoses" for steep drops, and two large drill rigs (described in the presentation as John Henry rigs) to install steel shear dowels—40 to 60 feet long rods grouted into the slope—to pin unstable blocks in place. The agency also described deploying automated monitoring systems: slope inclinometers, "shape arrays" that transmit movement data, and high‑frequency drone surveys and total‑station survey targets to measure daily shifts.

Why the upper slope work: Caltrans said attempts to remove material from the lower benches repeatedly caused undercutting and faster movement higher on the slope. That prompted a redesign that leaves a larger temporary bench above the rocky zone and a revised cut geometry. Caltrans described the finished working profile as a 1.5:1 slope near the top where it still needs stabilization, stepping to a 2:1 cut to reach a roughly 100‑foot working bench above the rocky toe where crews can operate.

Caltrans described intermittent behavior of the slide mass. Monitoring instruments placed in September showed immediate movement of up to 3 inches at some locations (one inclinometer "broke off almost immediately," the presenter said) and episodic movements afterward, including zones that moved as fast as about a foot per day when active. That rate forced crews to stop work, wait for movement to slow, and then resume when monitors indicated stability. "We would stop, and we'd evaluate," the presenter said.

On disposal and environmental approvals: Caltrans told the group the project is disposing material directly offshore because "there is no place to capture the material." The presenter said resource agencies and the Monterey Bay National Marine Sanctuary have been part of the process and that, in this case, sanctuary staff and other resource agencies signed off because direct ocean disposal was the only feasible option. The presenter said that while Caltrans is using remote equipment where possible, the scale and depth of the slide required traditional excavation and on‑slope drilling as well.

Equipment and logistics: Caltrans said it kept spider hoses and two remote dozers on site, brought a larger drill rig from out of state, and temporarily staged seven dozers and two John Henry drill rigs to keep pace with excavation. The agency described operating with a remote‑control setup for some dozers (operators controlling machines from an elevated vantage or via helicopter deployed video feeds) to keep people out of the most hazardous work zones.

Public safety and community concerns: Community members at the meeting urged more frequent public updates and raised safety concerns about workers' travel speeds. A South Coast resident, Sarah Harvey, said contractors' employees have been driving quickly through local neighborhoods and asked Caltrans for a contact able to handle complaints and accountability. Caltrans said its public information staff will expand outreach and provide regular updates to stakeholders.

Schedule and funding: Caltrans said the work is eligible for state funding and is expected to be federally reimbursable; it declined to provide a firm completion date. "We are working really hard to protect the work above us ... we just don't know," a Caltrans speaker said. The agency also said it has engaged third‑party consultants to validate the plan and make on‑the‑fly adjustments.

What happens next: Caltrans said it will continue daily monitoring, install additional shear dowels and a protective mesh, and proceed with the 2:1 cut to the working bench before resuming the final excavation toward the ocean. The agency also committed to regular stakeholder briefings and to creating a project webpage and distribution list to share updates and slide imagery.

"We're doing this as quickly as we can," the presenter told the advisory group, while repeatedly stressing that worker safety and slope monitoring determine when crews can safely operate.

Ending: For now, the road remains closed at the Regent’s Slide. Caltrans said it will continue to post updates through its public information office and through the county’s stakeholder channels; the agency did not provide a reopening projection and said that timeline will depend on instrumented slope behavior and the ability to complete the planned dowel and bench work first.