Drivers who use State Route 4 between the Bay Area and San Joaquin County face a 55-hour full highway closure this weekend. Caltrans will close SR-4 from Roberts Road to the Old River Bridge from 10:00 p.m. Friday, August 14, 2026, until 5:00 a.m. Monday, August 17.
That stretch is a common cut-through for Stockton, Discovery Bay, and East Contra Costa trips. If your weekend plan still pins SR-4 as the only path, rebuild it before Friday night rather than meeting a hard stop at the bridge.
- Where: State Route 4 from Roberts Road to the Old River Bridge.
- When: 10:00 p.m. Friday, August 14, to 5:00 a.m. Monday, August 17, 2026.
- Type: Full highway closure for about 55 hours.
- Also active: Long-term one-way control at Old River Bridge through November 2026.
- Alternates: Caltrans recommends SR-12 or Interstate 205 between Discovery Bay and Stockton for longer vehicles and through trips.
The official Caltrans District 4 advisory for August 9 to 17 lists the 55-hour full closure as a plan-ahead item for Bay Area and San Joaquin motorists. Caltrans QuickMap and the 511 SF Bay travel information system remain the live check surfaces for last-minute schedule shifts.
The same notice layers the weekend full closure on top of longer construction already running at the Old River Bridge on the San Joaquin and Contra Costa county line.
What the 55-hour full closure actually means
A full highway closure means through traffic cannot use SR-4 between Roberts Road and the Old River Bridge for the stated hours. Do not expect a single open lane, temporary shoulder path, or soft detour that keeps you on SR-4 through the work zone.
The window begins late Friday night and runs through early Monday morning, so Saturday and Sunday daytime traffic is inside the closed period. Late Friday arrivals and early Monday commute attempts are both at risk.
Caltrans frames the work as maintenance and construction inside San Joaquin County. The Farmington Highway Improvement Project context appears in the same advisory package for related overnight work farther east toward SR-99.
Treat the 5:00 a.m. Monday reopen time as planned, not guaranteed, until QuickMap shows the segment open again.
How this stacks with the long-term Old River Bridge control
Even outside the 55-hour full closure, Caltrans is running long-term 24-hour one-way traffic control on SR-4 at the Old River Bridge through November 2026. That control is a separate, ongoing constraint from the weekend full shutdown.
Vehicles longer than 34 feet are strongly urged to avoid the bridge control entirely. Caltrans points those longer vehicles to SR-12 or Interstate 205 between Discovery Bay and Stockton.
If you are towing a trailer, driving a shuttle van, or moving a rental truck, do not wait for the weekend full closure to force the decision. Use the long-vehicle alternate now and keep it for the full November construction season.
Overnight one-way control from Whiskey Slough Road in Holt to the Old River Bridge was also listed earlier in the August 9 to 14 night package, so midweek travelers already saw slower SR-4 operations before the full weekend outage.
Who should change routes before Friday night
Bay Area drivers heading to Stockton, Modesto, or Central Valley lodging should leave SR-4 off the default GPS preference for Saturday and Sunday. Preload SR-12 or I-205 before you lose signal in a work zone detour.
Hotel and Airbnb guests who booked properties assuming a fast SR-4 hop across the Delta should recheck arrival windows with hosts. A 55-hour closure can turn a 40-minute transfer into a much longer loop.
Rideshare and delivery drivers serving Discovery Bay, Brentwood, Antioch, and western San Joaquin County should treat SR-4 as closed for through trips all weekend and price longer alternates into the trip.
Travelers who still want a Bay Area city day on either side of the drive can use Deep Arrival’s San Francisco things to do guide to plan destination stops that do not depend on a quick SR-4 crossing.
| If you are… | What to do |
|---|---|
| Driving SR-4 between Discovery Bay and Stockton this weekend | Switch to SR-12 or I-205 before Friday night and ignore GPS suggestions back onto the closed segment. |
| Operating a vehicle longer than 34 feet | Avoid Old River Bridge one-way control entirely and use SR-12 or I-205 through November 2026. |
| Arriving to East Contra Costa or Stockton lodging late Friday | Leave early enough that you never need SR-4 after 10:00 p.m. Friday. |
| Depending on Monday morning reopen timing | Confirm QuickMap status before promising a tight airport or meeting transfer. |
| Using SR-4 only for local short hops near the bridge | Expect signed local detours and longer travel times even after the weekend full closure ends. |
Fuel and restroom planning matters more on the alternate highways. I-205 and SR-12 can absorb diverted volume, so service plazas and exits may queue even when the pavement is open.
Weather can shift construction windows. If Caltrans shortens or extends the full closure, the live channels on QuickMap, 511, and District 4 social updates are the authority, not a cached navigation app.
Freight and contractor traffic may still enter the work zone under separate rules that do not apply to ordinary passenger cars. Do not follow a truck into a closed gate and assume the road reopened for everyone.
If you are connecting a Bay Area flight to a Central Valley hotel, leave more buffer than the map’s free-flow estimate. A single missed alternate exit can push you onto surface roads that were never designed for diverted freeway volume.
Local emergency access and resident driveways can still operate under flagger control near the bridge. That is not a signal that the full highway segment is open for through trips from Roberts Road to Old River Bridge.
- Reroute now: Remove SR-4 Roberts Road to Old River Bridge from weekend itineraries.
- Long vehicle rule: Prefer SR-12 or I-205 if your vehicle is over 34 feet, all season through November.
- Friday night cutoff: Be off the closed segment before 10:00 p.m. August 14.
- Live check: Recheck Caltrans QuickMap before outbound and return legs.
- Monday buffer: Do not schedule a tight Monday morning transfer until the map shows reopen status.
If your navigation app still draws a blue line across the closed SR-4 segment, ignore it and follow the signed detour or the Caltrans alternate highways. The 55-hour full closure is a construction stop, not a soft slowdown.
Save the Caltrans statewide road conditions phone line, 1-800-427-ROAD, before you leave cell coverage in the Delta. A single call can confirm whether Monday morning reopen language still matches the field status.
When is the SR-4 full closure this weekend?
Caltrans schedules the full highway closure from 10:00 p.m. Friday, August 14, 2026, until 5:00 a.m. Monday, August 17, between Roberts Road and the Old River Bridge.
Which highways should drivers use instead?
Caltrans recommends SR-12 or Interstate 205 between Discovery Bay and Stockton, especially for longer vehicles.
Is the Old River Bridge only closed this weekend?
No. In addition to the weekend full closure, Caltrans is running long-term 24-hour one-way traffic control at the Old River Bridge through November 2026.
Do vehicles over 34 feet have special guidance?
Yes. Caltrans strongly recommends that vehicles measuring over 34 feet seek alternate routes such as SR-12 or I-205.
Where can travelers confirm live status?
Use Caltrans QuickMap, 511 SF Bay updates, District 4 channels, or 1-800-427-ROAD for statewide highway conditions.
