Vital work and detour to begin Feb. 2 and last about 18 months
EDITOR'S NOTE: This story has been updated. Please visit SR99-120connector.com for the latest project-related updates.
The Austin Road overcrossing of State Route 99 in Manteca is scheduled to be closed starting Sunday, Feb. 2, 2025, for about 18 months to allow critical construction on San Joaquin Council of Governments’ (SJCOG) State Route 99/120 Connector project.
The pivotal work to remove the 1950s-era Austin Road overcrossing, or bridge, in Manteca is the next major step in the highway-to-highway State Route 99/120 Connector project that will replace it with a longer structure spanning State Route 99 and Union Pacific Railroad tracks. In the long run, the work will improve safety, ease traffic congestion, enhance mobility and goods movement, and reduce greenhouse gas emissions for better air quality.
The overcrossing closure and detour are required so motorists can safely drive around the work and will be in place for about a year and a half. Electronic signs, additional directional signs and traffic controls will be in place to make the detour as seamless as possible for motorists. Commuters are encouraged to plan ahead, allow extra travel time, and consider carpooling or using public transit where possible. Additionally, SJCOG recommends that travelers sign up to receive construction-related updates via text or by email by visiting SR99-120connector.com.
“The safety of motorists driving through the area is our No. 1 priority,” said Gwen Owens, the State Route 99/120 Connector project manager for the San Joaquin Council of Governments (SJCOG). “That’s why we’re committed to carrying out this very important project. This detour is necessary while we take down the overpass and replace it with one that better meets the needs of everyone for well into the future. And we wanted motorists to know as soon as possible about the detour so they can plan accordingly.”
The overcrossing closure could be delayed due to forecasted inclement weather. Even so, Austin Road will be closed Sunday evening, Feb. 2, to Friday evening, Feb. 7, to through traffic from West Ripon Road to Moffat Boulevard for related irrigation work. Only local traffic will be allowed on Austin Road.
SJCOG is leading the State Route 99/120 Connector project with partners, including the cities of Manteca and Ripon, and Caltrans. The State Route 99/120 interchange is a major regional transportation hub vital for moving people and goods throughout Northern California. Motorists living, working and traveling in San Joaquin County will be able to get where they need to be more safely and smoothly once the work is completed. Work began in summer 2024 and will continue for roughly two years.
Removing the current Austin Road overcrossing and replacing it with a new one is necessary to accommodate additional lanes on State Route 99 and Union Pacific Railroad tracks.
Construction work is subject to change without notice due to inclement weather or other factors. Travelers in this area should pay attention to posted signs and slowdown in the cone zone.

The detour around the overcrossing work includes:
From Northbound Austin Road to Austin Road North of the State Route 99 Interchange:
- Westbound Singh Street.
- Northbound East Atherton Drive.
- Eastbound East Woodward Avenue.
- Northbound Moffat Boulevard.
- Northbound Spreckels Avenue.
- Eastbound East Yosemite Avenue.
From Austin Road north of the State Route 99 Interchange to Moffat Boulevard:
- Northbound Austin Road.
- Westbound East Yosemite Avenue.
- Southbound Spreckels Avenue.
From northbound or southbound Moffat Boulevard to northbound Austin Road:
- Northbound Spreckels Avenue.
- Eastbound East Yosemite Avenue.
From eastbound East Woodward Avenue to Northbound Austin Road:
- Northbound Moffat Boulevard.
- Northbound Spreckels Avenue.
- Eastbound East Yosemite Avenue.

The detour around the upcoming work for Feb. 2-7 includes:
For Northbound Traffic:
- Eastbound West Ripon Road.
- Northbound South Main Street.
- On-ramp to State Route 120.
To learn more and sign up for project updates, visit SR99-120connector.com.
The project hotline: (209) 209-4690.
Project email address: 99-120connector@sjcog.org.