RECEIVE update on State Route 156/Castroville Boulevard Interchange project and presentation of concept design

Caltrans has begun the design process for the State Route 156/Castroville Boulevard Interchange project.  This project update gives a brief overview of the project and presents an interchange concept with roundabout control, instead of traffic signals at the each ramp intersection.

The State Route 156/Castroville Boulevard Interchange project is the first of three segments that make up the larger State Route 156 Widening project. The proposed budget is estimated at $42,950,000, assuming funding from the following sources:

$  2,150,000  Measure X (secured)

$19,800,000  State Transportation Improvement Program (secured)

$  5,000,000  Regional Development Impact Fees (secured)

$16,000,000  Senate Bill 1 (SB1) Trade Corridor funds (future application)

SB1 Trade Corridor funding would not be available if Proposition 6 (on the November ballot) passes, repealing the SB 1 gas taxes; this would result in a funding shortfall for this project.

The State Route 156/Castroville Boulevard Interchange project removes the existing signalized intersection on State Route 156 at Castroville Boulevard and constructs a new grade-separated interchange east of the existing intersection. The initial concept for the State Route 156/ Castroville Boulevard Interchange project included traffic signal control at each of the new ramp intersections and the intersection of the realigned new Castroville Boulevard and the old alignment of Castroville Boulevard. The proposed concept replaces the traffic signals with roundabouts.

Roundabout control at the ramp intersections allows the proposed bridge over State Route 156 to be narrower and reduce construction costs. Roundabouts will perform better than traffic signals and have a longer design life. Roundabouts allow the Castroville Boulevard interchange to have full independent utility and accommodate future segments of the State Route 156 Widening project, as well as a future Blackie Road connection. The roundabout proposed at the intersection of the realigned new Castroville Boulevard and the old alignment of Castroville Boulevard offers safe pedestrian and bike crossings between North County High School and the recently completed bike / pedestrian bridge into Castroville.