Caltrans District 10 work on HWY 4 impacting Contra Costa/BAY AREA motorists to/from San Joaquin County (August 9-17, 2026)

LONG-TERM ONE-WAY TRAFFIC CONTROL AT OLD RIVER BRIDGE

San Joaquin County - The California Department of Transportation (Caltrans) will perform various closures on State Route 4 (SR-4) for maintenance and construction work within San Joaquin County. Work will occur as follows:

• Long-term, 24-hour, one-way traffic control will be implemented on SR-4 at the Old River Bridge (San Joaquin/Contra Costa County line) for construction through November 2026.
  • Vehicles measuring over 34 feet in length are strongly recommended to seek alternate routes. SR-12 or Interstate 205 are highway alternatives between Discovery Bay and Stockton.
• Overnight, one-way traffic control from Whiskey Slough Road in Holt to the Old River Bridge for construction beginning Sunday, August 9, through Friday, August 14, from 8:00 p.m. until 4:00 a.m.
  • Plan Ahead: 12-hour full highway closure from Roberts Road to Old River Bridge scheduled from 7:00 a.m. until 7:00 p.m. on Sunday, August 9, 2026.
  • Plan Ahead: 55-hour full highway closure from Roberts Road to Old River Bridge scheduled from 10:00 p.m. on August 14, until 5:00 a.m. on August 17, 2026.
• Overnight, intermittent one-way traffic control from SR-99 to the San Joaquin/Stanislaus County line for pavement work beginning Sunday, August 9, through Friday, August 14, from 7:00 p.m. until 7:00 a.m.
  • The above closure is required as part of the SR-4 Farmington Highway Improvement Project. For details visit State Route 4 Capital Maintenance | Caltrans