Overnight Full Closures of State Route 84 Begin May 18 for the Arroyo de la Laguna Bridge Project in Unincorporated Sunol

Alameda County - As part of the Arroyo de la Laguna Bridge Project, Caltrans will begin construction activities on Monday, May 18, requiring Monday-Friday overnight full closures of State Route 84 (Niles Canyon Road) between Main Street and Bond Street in Sunol. The closures will run from 8:00 PM to 5:00 AM for approximately four weeks.

For the safety of crews and motorists, Caltrans will implement full closures in this area while work is underway. Daytime construction will follow and continue through October. Additional traffic advisories will be sent as the project progresses.

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 is scheduled to begin in May 2026, starting with Stage 1 on the north side.

Closure Details

SR-84 between Main Street and Pleasanton Sunol Rd, Sunol
Monday to Friday nights
Beginning May 18 for approximately four weeks
8:00 PM to 5:00 AM
During the nightly closures, motorists will be detoured around the work zone.

All work is weather dependent.

Detours:

Drivers traveling toward Main Street (Sunol):

• Turn right onto Main Street
• Turn left onto Kilkare Road
• Turn right onto Foothill Road
• Turn right onto Castlewood Drive
• Turn left onto Pleasanton-Sunol Road
• Turn right to access the I-680 on-ramp

Drivers traveling from Bond Street toward SR-84:

• Turn left onto Main Street
• Turn left onto Kilkare Road
• Turn right onto Foothill Road
• Turn right onto Castlewood Drive
• Turn left onto Pleasanton-Sunol Road
• Enter I-680 using the on-ramp on the right

Drivers traveling from Livermore toward Sunol:

• Take the right connector to I-680
• Stay right to merge
• Exit right at Sunol Blvd
• Turn right onto Sunol Blvd
• Turn right onto Castlewood Drive
• Turn left onto Foothill Road

Drivers traveling from Pleasanton-Sunol Road:

• Continue straight
• Turn right onto Koopman Road
• Turn left onto the I-680 on-ramp
• Exit right at Sunol Blvd
• Turn right onto Sunol Blvd
• Turn right onto Castlewood Drive
• Turn left onto Foothill Road

Drivers heading toward Fremont:

• Take the right connector to I-680
• Stay right to merge
• Exit right at Mission Blvd
• Continue straight on Mission Blvd

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. Drivers are encouraged to check out QuickMap http://quickmap.dot.ca.gov/ Motorists can also receive 24/7 highway condition information statewide by calling 1-800427-ROAD or 1-800-427-7623.

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