Transportation Agency for Monterey County

Highway 156

The State Route 156 West Corridor project consists of constructing a new four-lane highway, called the Monterey Expressway, parallel and immediately south of the existing SR 156; a new SR 156 to US 101 interchange and a rerouting of the traffic from San Miguel Canyon Road to US 101; and a full interchange at SR 156 and Castroville Boulevard.  The existing SR 156 roadway will be converted into a frontage road to provide access to the local community, and also to serve as a state-required toll-free parallel route.

The total estimated cost to construct this project using the conventional delivery process is $365 million, or $375 million under a tolling scenario.  Currently $70 million has been secured or pledged for the project, including $18 million in FORA and TAMC impact fees.  Facing a $295 million funding gap, the Transportation Agency Board of Directors approved an in-depth evaluation of tolling as an option to deliver the project.

Level 2 Tolling Study

The Level 2 Traffic and Revenue Study (Tolling Study) analyzes current and future traffic diversion, potential toll rates, toll discounts for local residents and business, and addresses other questions and concerns brought up by the Board and the public that were adopted by the Board of Directors as “Guiding Principles” for evaluating tolling. Toll collection would be done 100% electronically via a gantry system over the expressway, similar to Fastrak in the Bay area; booths for cash collection of tolls will not be provided.  A camera detection system would be used to collect tolls from users without Fastrak transponders.  A toll exemption for local residents and business in the Castroville-Prunedale area was factored into the modeling analysis and results in a 15% reduction in revenues. The revenue lost from providing a partial or full local discount would increase the funding shortfall amounts projected by the study.

The Tolling Study evaluates the project feasibility and financing structure over 50 years under two delivery options.  A Public Delivery option proposes that the Transportation Agency and/or Caltrans procure financing, manage design and construction, then operate and maintain the toll facility.   Under the Public-Private-Partnership (P3) Delivery option, the financing, design, construction, and ongoing operation and maintenance of the toll road would be managed by a private partner/concessionaire in accordance with terms negotiated under a concession agreement. It is worth noting that the Public-Private Partnership authorization in state law expired on January 1, 2017 and has yet to be renewed.

Both delivery options assume securing financing in the form of bonds and federal infrastructure loans to construct the project. The P3 option includes additional private equity in the financing package, assumes reduced project construction costs, and assumes a project delivery time period three years shorter than the Public Delivery option. The Tolling Study evaluates the feasibility of delivering the project based on the timing and availability of various fund sources under both options over a 50 year time horizon. In addition to the project delivery (design, right-of-way, build) costs of $375 million, the analysis assumes that the toll revenues will also be utilized to cover the cost of financing the bonds and loans, maintaining the new expressway, operating the toll facility over time, and reconstructing the facility when it reaches the end of its lifespan.

The Transportation Agency Board of Directors will consider receiving the study at their December 6, 2017 meeting.

2017 SR156 Level 2 Traffic & Revenue Study_EXECUTIVE SUMMARY

SR156 Level 2 Traffic & Revenue Study

Benefits of the State Route 156 West Corridor Project:

  • Improves safety at intersections and local access
  • Provides traffic congestion relief for 32,000 vehicles per weekday
  • Supports $2 billion per year visitor economy
  • Facilitates movement of valuable goods to market, supports $3.8 billion per year agricultural industry

Get Involved


Highway 156 West is one of the major thoroughfares used by residents, commuters, tourists, and commercial trucks traveling to and from the Monterey Peninsula. As a result, more than 32,000 vehicles travel along this route each weekday, and Highway 156 experiences periods of heavy congestion, especially on weekends. This narrow two-lane highway can no longer accommodate this amount of traffic.

With concerns about safety and congestion, Highway 156 West has been identified by Caltrans and the Transportation Agency for Monterey County as one of the key transportation issues that must be addressed.  The Highway 156 West Corridor Improvement Project is designed to do that. The project would construct a new four-lane highway parallel to the existing Highway 156 with new interchanges constructed at Castroville Boulevard and at U.S. 101. The current two-lane highway will be converted into a frontage road that would serve the local community.  The result would be improved safety and traffic flow in the area for all drivers.

Current Cost:

$375 million

Current Stage:

Supplemental Environmental Impact Report

Additional Information
Caltrans 156 Webpage Nov. 11, 2006 Open House
Summary Report (2mb pdf)
Final Environmental Impact Report Final Environmental Impact Report Response to Comments
Route 156 West Project Map  156 Q&A as of 9/18/2014
Route 156 West Presentation Level 1 Sketch Level 156 Toll Road Study and Appendices
Route 156 West PDA  P3 Workshop Presentation How Electronic Tolling Works: Video from Washington State
Public-Private-Partnerships in California Public-Private-Partnerships Nationally
Route 156 West Guiding Principles
Contact Information

Transportation Agency for Monterey County

Todd Muck  Todd@tamcmonterey.org
(831) 775-4407

David Silberberger
(805) 549-3798