The $88 million State Route 156 Improvement Project, known as “The Gap,” extended the four-lane expressway from San Juan Bautista to the Hollister Bypass. Improvements began near San Juan Bautista, from The Alameda to 0.2 mile east of Fourth Street/State Route 156.
The project widened approximately 4.5 miles of existing two-lane highway into a four-lane expressway. In addition, crews constructed 3.5 miles of new roadway alignment using continuously reinforced concrete pavement (CRCP). The new roadway features 12-foot travel lanes and paved shoulders ranging from 4 to 8 feet wide.
Additional improvements included widening the San Juan Creek Bridge and constructing the East Ditch Bridge at Mission Vineyard. The project also included a retaining wall with an integrated sound wall and a new roundabout. Furthermore, crews modified traffic signals at three intersections, improved drainage systems, and relocated water mains.
Roadside improvements included ditches along both sides of the alignment. These ditches feature 4:1 side slopes and 10-foot widths.
The project also created a new intersection at Union Road and realigned San Juan Hollister Road eastward. This work required significant excavation, including construction of a cut slope reaching approximately 67 feet in height. Supporting improvements included new farm access roads. Additionally, crews placed an asphalt overlay along the existing State Route 156.
BKF provided resident engineering, structure representative, construction inspection, and office engineering support services to Caltrans throughout construction. The team also coordinated with multiple jurisdictions, utilities, and project stakeholders. For example, BKF coordinated with Pacific Gas and Electric Company (PG&E) during the replacement of a gas transmission main. In addition, the team participated in interagency coordination to address construction needs and support successful project delivery.
