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

Published:

Contra Costa County — Caltrans will perform overnight paving and maintenance work on eastbound and westbound State Route 4 (SR-4) between Cummings Skyway and Alhambra Avenue / Interstate 80 in Martinez. Work will take place nightly beginning November 3, 2025, through November 12, 2025, weather permitting. Closures will occur between 7:00 PM and 5:00 AM. Monday through Saturday.

Closure Schedule:

  • SR-4 EB/WB Cummings Skyway ↔ Alhambra: November 3
  • SR-4 WB Alhambra → Cummings: November 4–5
  • SR-4 WB Cummings Skyway → I-80: November 6–7
  • SR-4 EB I-80 → Cummings Skyway: November 8, 10
  • SR-4 EB Cummings Skyway → Alhambra EB: November 11–12

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

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

November 3, November 10 & 11

  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 

Map highlighting the detour route for the  closure of eastbound State Route 4 between Cummings Skyway and Alhambra Road in Contra Costa County. Exit Cummings Skyway Offramp; Left on Cummings Skyway; Right on Franklin Canyon Rd.; Left on Alhambra Ave.; Right on EB 4 Onramp

Detour Plan for WB SR-4 traffic from Alhambra Ave to Cummings Skyway

November 3, 4 & 5

  1. Exit Alhambra Avenue
  2. Turn left on Alhambra Avenue and turn right to Franklin Canyon Road 
  3. continue on Franklin Canyon Road
  4. Re-enter WB SR-4 via the Cummings Skyway on-ramp

Detour map for Westbound State Route 4 Full Closure from Alhambra to Cummings Skyway. 1. Exit Alhambra Avenue. 2. Turn left on Alhambra Avenue and turn right to Franklin Canyon Road continue on Franklin Canyon Road. 3. Re-enter Westbound SR-4 via the Cummings Skyway on-ramp

Detour Plan for WB SR-4 Traffic from Cummings Skyway to I-80

November 6 & 7

  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 Map for the closure of Westbound SR-4 between Cummings Skyway and San Pablo Avenue. 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

November 8 & 10

  1. Continue EB 80 to Cummings Skyway Exit
  2. Exit on Cummings Skyway Rd.
  3. Right on Cummings Skyway Rd.
  4. Right on EB Hwy 4 Onramp

Detour map for Eastbound State Route 4 from Interstate 8- to Cummings Skyway. Continue EB 80 to Cummings Skyway Exit; Exit on Cummings Skyway Rd.; Right on Cummings Skyway Rd.; Right on EB Hwy 4 Onramp

**Be advised reverse one-way traffic control and temporary traffic signal near I-80 at Cummings Skyway Overcrossing **

Please follow posted signs and detour routes during the closure periods. Motorists are advised to expect delays, reduce speed in the construction zone, and allow extra travel time.

Caltrans appreciates the public’s patience while we complete this important roadway improvement work.

Motorists are advised to expect delays and allow extra time. For 24/7 traffic updates, follow 511.org on Twitter. For real-time traffic, visit Caltrans QuickMap

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