101 Prairie Creek Curve Improvement Project

Caltrans proposes to improve an existing, non-standard compound curve on U.S. Highway 101 from postmile (PM) 125.20 to 125.62 in Humboldt County. The purpose of the project is to improve safety and reduce the frequency and severity of collisions. The project is needed because this segment of the highway experiences a higher rate of collisions than the statewide average.

Project Description

The proposed project consists of shoulder widening and superelevation improvements to improve the drivability of the curve. The existing curve is a compound curve with a larger radius of 800 feet and a smaller radius of 350 feet. The superelevation through the curve would be increased to about12% with standard superelevation transitions into and out of the curve. The northbound shoulder would be widened to a range of 5 to 6 feet, and the southbound shoulder would be widened to arrange of 2 to 6 feet within the Caltrans right of way. The existing metal beam guardrail would be upgraded to a Midwest guardrail system. The existing minor-concrete vegetation control would also be removed and replaced at a width of 2 feet below the guardrail. Hot mix asphalt would be placed along the northbound shoulder to limit erosion at the toe of the embankment. The project is also proposing to replace the five existing culvert systems and construct one new system within the project limits.


At this time, Caltrans anticipates beginning construction by 2025.

Estimated Traffic Impacts

A lane closure will be required with one-way traffic control during construction. Bicyclists will be accommodated.

For more information, contact:

Project Manager
David Melendrez
(707) 572-0831

Environmental Coordinator
Cassie Nichols
(707) 492-0174

Public Information Officer
Myles Cochrane
(707) 498-4272

Last reviewed: May 2023

U.S. 101 two-lane roadway at postmile 125.20 to 125.62 in Humboldt County.

U.S. 101 two-lane roadway at postmile 125.20 to 125.62 in Humboldt County.

Current view of project area