Highway 25/U.S. 101 interchange work to begin this month

Map shows the Phase 1 work that will be done at the U.S. 101/Highway 25 interchange. Map courtesy VTA.

EIR comment period for widening Highway 25 extended through Dec.

By Robert Airoldi

Workers who commute north from Hollister and points south will see work begin on the U.S. 101/Highway 25 interchange this month. The three-year project will be done in two phases and will ease traffic for those who work in Gilroy, San Martin and Morgan Hill.

Phase 1, which will cost an estimated $136 million, will begin in April. Karsten Adam of VTA said at the Nov. 20 Mobility Partnership meeting that the work scheduled to begin in April includes constructing a new four-lane bridge just north of the existing one, extending the on/off ramps and adding two traffic signals. The Mobility Partnership is a committee made up of elected representatives from Santa Clara and San Benito counties.

It also includes the construction of a separate two-way bike lane between Castro Valley Road and the U.S. 101/Highway 25 interchange. Castro Valley and Mesa roads will both be closed.

In the meantime, preparation is underway to relocate gas lines and replace wells. Santa Clara Valley Transportation Authority  VTA anticipates it will remove trees in the area in December and January ahead of the nesting bird season. It also plans to tear down the Garlic Shoppe, which has already been relocated.

Santa Clara County’s Measure B will fund $77 million for the project and Senate Bill 1, California’s Road Repair and Accountability Act of 2017, will fund $59 million.

In 2026, VTA expects to finish all ramps and start “falsework”— the temporary structure used to support a permanent structure until it can support itself — for the main bridge over U.S. 101. Construction is expected to be completed in 2027, including demolishing the old overcrossing.

Adam said there will be eight detours implemented throughout the project for weekend and overnight work. Sometime in 2025, motorists on 25 connecting to southbound U.S. 101 will be directed to take northbound 101 to Monterey Road, where they can access the southbound ramp.

Cyclists will be detoured to Bloomfield Avenue and then Bolsa Road for the duration of the project.

“It’s hard to predict exactly what the delays are going to be,” Adam said. “We’re trying to minimize those, of course. The detours, for example, will mainly happen at night, off- peak hours. Otherwise you’ll see general types of delays you see at construction sites.”

According to the VTA website, the U.S. 101/Highway 25 interchange is more than 30 years old and cannot accommodate current traffic demands which include commuters, commercial and recreational traffic.

“These conditions, coupled with high travel speeds, have resulted in higher-than-average accident rates in the interchange area, and traffic backups onto southbound U.S. 101,” the website states.

It is common to see a line of motorists using the shoulder from Uvas Creek onto the interchange, a stretch of more than half a mile.

Phase 2 of the project has an estimated cost of $35 million and includes connecting Highway 25 to Santa Teresa Boulevard. Construction is expected to take place between 2027 and 2029. No funding has been approved.

The interchange is part of a larger project to widen U.S. 101 from four to six lanes between Monterey Road and Highway 129, build a bridge on Highway 25 over the Union Pacific Railroad tracks, construct a flood bridge west of the tracks and install pedestrian and bike connections.

DeSilva Gates-Viking was awarded the contract for the interchange project.

There $82.5-million bid was the lowest of the six submitted to the VTA. The other bids ranged from $92.3 million to $104.7 million.

Meanwhile, the comment period for the Highway 25 Corridor Improvement Project has been extended.

Caltrans, in association with the Council of San Benito County Governments, and the Santa Clara Valley Transportation Authority, proposes improvements along Highway 25 within San Benito and Santa Clara counties, between the cities of Hollister and Gilroy. The project proposes modifications to the corridor. Potential improvements being studied for feasibility include: realignment, lane additions, a new interchange, modified access control, new frontage roads, and transit improvements.

As required by the California Environmental Quality Act, Caltrans distributed a Notice of Preparation and is requesting comments from responsible agencies, trustee agencies, and the public regarding the significant environmental issues, reasonable alternatives, and reasonable mitigation measures that will be discussed in the Environmental Impact Report. A copy of the NOP document can be found on the Caltrans District 5 website (https://dot.ca.gov/caltrans-near-me/district-5/district-5-current-projects/05-48541).