Early Morning Northbound I-280 to Southbound SR-1 Ramp Closures on April 17 & 21

San Mateo County ― Caltrans will close the northbound I-280 ramp to southbound State Route 1 (SR-1) in Colma to construct an asphalt concrete dike and remove temporary concrete barriers in the early morning hours on:

• Friday, April 17, from 1 a.m. to 6 a.m.
• Tuesday, April 21, from 1 a.m. to 7 a.m.

Detour: Take the Junipero Serra off-ramp, turn left on Junipero Serra Blvd., turn left on San Pedro Rd., turn left on Sullivan Ave., and enter the southbound SR-1 on-ramp.

Please follow detour signs and drive with caution. All work is weather dependent.

Thank you for your patience as we work to maintain our state’s highways, bridges, and tunnels;

For 24/7 traffic updates, please visit 511.org: https://x.com/511SFBay
For real-time information, visit Caltrans QuickMap: https://quickmap.dot.ca.gov
Follow us on X: https://x.com/CaltransD4
Or call 1-800-472-7623, 1-800-427-ROAD for state highway conditions statewide.