Image courtesy of Caltrans.

Information provided by Caltrans District 5. Lea este artículo en español aquí.

Overnight Southbound On and Off-Ramp closures at US 101/SR 25 on May 30, 2025, from 9:00 p.m. to 6:00 a.m.

As part of the US 101/SR 25 Interchange – Phase 1 Project, the southbound on- and off-ramps at the interchange will be closed overnight on Friday, May 30, from 9:00 p.m. to 6:00 a.m. Saturday, May 31.

Please plan and follow posted detours. We appreciate your patience as we work to improve safety and mobility in the area.

What’s closed?

If you’re driving southbound on US 101, you can’t take the usual off-ramp exit to Highway 25 because that ramp will be temporarily closed overnight for construction (shown in red on the map, MI-2).
 

When will it be closed?

The southbound US 101 off-ramp exit to Highway 25 will be temporarily closed overnight on Friday, May 30, from 9:00 p.m. to 6:00 a.m. Saturday, May 31.
 

What’s the detour?

Instead of exiting the US 101 southbound off-ramp to Highway 25:

  1. Stay on southbound US 101 past the closed off-ramp exit.
  2. Take the Betabel Road off-ramp exit.
  3. Turn left at Betabel Road, cross over US 101, and take the US 101 northbound on-ramp entrance.
  4. Stay on northbound US 101 and take the off-ramp exit to Highway 25.
Image courtesy of Caltrans.

Northbound State Route 25 to Southbound US 101


What’s Closed?

If you’re driving northbound on Highway 25, you can’t take the usual on-ramp entrance to southbound US 101 because that ramp is temporarily closed for construction (highlighted in red on the map, MI-3).
 

When will it be closed?

The northbound Highway 25 on-ramp entrance to southbound US 101 will be temporarily closed overnight on Friday, May 30, from 9:00 p.m. to 6:00 a.m. Saturday, May 31.
 

What’s the Detour?

Instead of taking the on-ramp entrance to southbound US 101:

  1. Take the Highway 25 on-ramp entrance to northbound US 101
  2. Stay on northbound US 101 and exit the off-ramp to Monterey Street.
  3. Turn left at Monterey Street, cross under US 101, and take the US 101 southbound on-ramp entrance.
Image courtesy of Caltrans.

Why are the southbound on and off ramps temporarily closing overnight?


These closures are necessary to safely remove topsoil adjacent to the ramps as part of ongoing site preparation work.
 
The temporary inconvenience serves the long-term goal of improving traffic operations and safety at the historically traffic-plagued highway interchange, addressing the current problems of higher-than-average accident rates in the interchange area and traffic backups onto southbound US 101.

Project Objectives

  • Improve connectivity between US 101 and SR 25
  • Improve traffic operations along US 101 and SR 25 with added ramp storage and signals
  • Enhance safety within the interchange area by reducing ramp backups onto southbound US 101 and providing improved access for safer merges
  • Support the overall future interchange reconfiguration, including US 101 and SR 25 widening, and future SR 152 improvements between US 101 and SR 156

Project Features

  • Phase 1 will reconstruct the US 101/SR 25 interchange slightly north of the current interchange.
  • Replace the SR 25 two-lane overcrossing with a four-lane overcrossing spanning across US 101
  • Increase the length of the southbound US 101 off-ramp to SR 25 to decrease traffic backups onto US 101
  • Upgrade the northbound US 101 ramps to improve exit and merging operations
  • Install new traffic signals at the ramp intersections to improve traffic flow
  • Construct a separated 2-way bikeway between Castro Valley Road and the southbound 101/SR 25 intersection.

For all other information, visit the project page at www.vta.org/sr25, email Community Outreach at community.outreach@vta.org, or call 408-321-7575.