Relief is on the way for drivers who use the US 101 and SR 92 interchange in San Mateo and Foster City — often criticized for its congestion, tricky merges and tight off-ramps.
A construction project started this week to increase safety, alleviate traffic bottlenecks and make it easier for drivers to navigate the area.
This is not a freeway expansion project, and all improvements will be constructed on existing Caltrans property. A separate study of a potential “direct connector” between the 101 express lanes and SR 92 is still under review.
What’s Changing?
This project will bring several upgrades that will make getting around safer and more efficient. The improvements include redesigned ramps, better merging areas and clearer lane markings. These changes will help reduce sudden lane changes and weaving, which can lead to crashes and slowdowns. The updates will also improve access to local roads and support smoother traffic flow throughout the area.
Here’s a quick breakdown of what’s being improved:
- SR-92 west to US 101: Modifying the southbound loop ramp and nearby structures
- US 101 to SR-92 east: Enhancing the merging area and updating lane striping
- US 101 south to Fashion Island Blvd: Making off-ramp changes for easier, safer exits
- US 101 north at Hillsdale Blvd: Improving the northbound off-ramp and nearby intersection
To see more detailed explanations of the planned work, see the Caltrans project fact sheet.
Who’s Behind the Project?
This is a collaborative effort between the TA, the City/County Association of Governments of San Mateo County (C/CAG), and Caltrans District 4. The cities of San Mateo and Foster City are also key partners in planning and supporting the work.
Where Is the Work Happening?
The project covers the US 101 corridor between Hillsdale Boulevard and Kehoe Avenue and SR 92 just west of the Hayward-San Mateo Bridge.
When Will It Happen?
Construction began on April 28 and will continue through summer 2028. During that time, there may be periodic traffic impacts, but the long-term payoff will be a safer, more efficient interchange for everyone.
Caltrans has scheduled overnight ramp closures in the southbound direction on U.S. 101 onto State Route 92 in both directions in Foster City starting on Monday, April 28 at 8 p.m. The ramps will be closed intermittently every night until Thursday, May 1 at 5 a.m.
You can always find the latest real-time closures on the Caltrans QuickMap.
Stay in the Loop
Want to learn more or have questions? Reach out to Caltrans Public Information Officer Jeneane Crawford at:
- Email: Jeneane.Crawford@dot.ca.gov
- Phone: (510) 390-3253
We’ll continue to share updates as the project moves forward. Thanks for your patience and support as we work to improve how we all move through San Mateo County!