Notice Cause
Construction
Notice Effect(s)
Detour
Lane Closure
Traffic Delays
Start Date
What
 MAP.Spanish.png "Starting April 16, 2025: Mesa Road and Castro Valley Road accessed closure on southbound US 101")
Starting April 16, 2025, Castro Valley Road and Mesa Road will permanently close, meaning drivers won’t be able to access US 101 from these roads anymore.
Why
A new and improved southbound off-ramp from US 101 to SR 25 is being built. The new ramp will be twice as long as the current one, making it safer and smoother for drivers.
A new bike path will also be added alongside the off-ramp, giving cyclists a safe way to travel between Santa Teresa Blvd and the 101/25 interchange. Cyclists can enter the bike path from a new roundabout at the end of Castro Valley Rd.
Because of these changes, vehicle access between Castro Valley Rd, Mesa Rd and US 101 will be closed.
Detour
- Use Thomas Rd to Luchessa Ave, then Monterey Rd to reach US 101 or SR 25.
- Heading to Gavilan College? Take Monterey Rd, then Luchessa Ave to Thomas Rd and onto Santa Teresa Blvd.
Traffic Impacts
- Access at US 101/Castro Valley Rd and US 101/Mesa Rd will be permanently closed
- Use Thomas Rd to Luchessa Ave, then Monterey Rd to reach US 101 or SR 25.
- Heading to Gavilan College? Take Monterey Rd, then Luchessa Ave to Thomas Rd and onto Santa Teresa Blvd.
Pedestrian Impacts
- No changes for pedestrians.
- Cyclists can use the new bike path when completed.