Overnight Lane Closures on State Route 4 (SR-4) in Contra Costa County Martinez Area – Alhambra Avenue to Interstate 80

Contra Costa County — Caltrans will perform overnight paving and maintenance work on State Route 4 (SR-4) between Cummings Skyway and Alhambra Avenue / Interstate 80 in Martinez. Work will take place nightly beginning October 28 through November 1, 2025, weather permitting.

Closures will occur between 7:00 PM and 6:00 AM. Monday through Saturday.

Full Closure Schedule:

• SR-4 WB-Cummings Skyway → I-80 : October 28
• SR-4 EB- I-80 → Cummings Skyway : October 29–31
• SR-4 EB-Cummings Skyway → Alhambra: November 1

**Please note this schedule is tentative and subject to change depending on weather conditions and construction progress.**

DETOUR PLAN FOR WB SR-4 TRAFFIC from CUMMINGS SKY TO I-80 October 28

1. Exit Cummings Skyway Offramp.
2. Turn right onto Cummings Skyway Road.
3. Turn left onto the westbound I-80 Onramp.
4. Exit at the San Pablo Avenue Offramp.

DETOUR PLAN FOR EB SR-4 TRAFFIC from I-80 TO CUMMINGS SKYWAY October 29-31
*Commuters from NB/SB San Palo to EB SR-4 should take EB I-80 onramp and exit at Cummings Skyway to EB-SR-4.

1. Continue east on I-80 to the Cumming Skyway exit.
2. Exit onto Cumming Skyway Rd.
3. Turn right onto Cumming Skyway Rd.
4. Turn right onto the EB Highway 4 onramp.

Detour Plan for EB SR-4 traffic from Cummings Skyway to Alhambra November 1:

1. Exit Cummings Skyway Offramp.
2. Left on Cummings Skyway
3. Right on Franklin Canyon Rd.
4. Left on Alhambra Ave.
5. Right on EB 4 Onramp