14-Hour Full Closure of SR-84 (Niles Canyon Road) at Arroyo de la Laguna Bridge for Girder Installation

6 p.m. Saturday, Sept. 26 through 8 a.m. Sunday, Sept. 27

Alameda County - Caltrans is scheduled to fully close SR-84 at the Arroyo de la Laguna Bridge in Sunol from 6 p.m. Saturday, September 26, through 8 a.m. Sunday, September 27, as crews install six precast concrete girders for the new bridge.

Crews will use a crane to lift and place six precast concrete girders that will form the structural support for the new bridge deck.

A full closure is necessary to provide crews with a safe work area for the crane operation and girder installation.

Closure Schedule
Saturday, September 26 - Sunday, September 27

• Full closure: 6 p.m. Saturday to 8 a.m. Sunday
• Location: SR-84 at the Arroyo de la Laguna Bridge in Sunol
• Work: Installation of six precast concrete bridge girders
• Reopening: All closures are scheduled to be removed by 8 a.m. Sunday

Motorists traveling through Sunol should expect delays and allow additional travel time. Please follow all posted signs and directions from crews in the area.

DETOURS:
Eastbound SR-84:
Motorists traveling eastbound on SR-84 from Fremont will be directed onto Main Street, then north on Kilkare Road and Foothill Road. Motorists will continue north on Castlewood Drive, east on Pleasanton-Sunol Road, and then use the I-680 on-ramp.

Westbound SR-84:
Motorists traveling westbound on SR-84 from Livermore will be directed to northbound I-680 and take Exit 25 Sunol Boulevard off-ramp. Motorists will then travel west on Sunol Boulevard and Castlewood Drive, then south on Foothill Road toward SR-84

All work is weather and schedule dependent.

Project Information
Caltrans is replacing the Arroyo de la Laguna Bridge, which was built in 1939, to ensure a safer and more dependable connection along SR 84.

The new bridge will:

• Provide a wider, safer roadway
• Add ADA-compliant sidewalks
• Improve safety through Niles Canyon and Sunol
• Support better travel between Pleasanton, Sunol, Fremont, and Livermore

Construction of the replacement bridge began in May 2026 with Stage 1 on the north side.

Project Website: Arroyo De La Laguna Bridge Project | Caltrans

Changeable message signs will be activated to guide motorists through the detour.

Caltrans advises motorists to allow extra travel time and use alternative routes when possible. Caltrans will update its Social Media pages with the latest highway conditions.

Caltrans thanks the public for their patience and cooperation as we continue to improve California's transportation network.