The State Route 99/120 Connector project is a major infrastructure initiative designed to enhance safety, traffic flow, and reduce congestion in Northern California’s Megaregion. This two-year project, led by SJCOG and its partners, will improve the critical highway-to-highway link between State Routes 99 and 120. By adding lanes, improving ramps, and upgrading nearby streets, the project aims to facilitate smoother and safer travel for residents, workers, and freight, all while reducing greenhouse gas emissions and enhancing air quality in the Central Valley. Phase one began in August 2024 and will continue for two years, providing a more reliable and efficient commute upon completion.

The improvements to the State Route 99/120 Connector are essential to bolster regional safety, reduce congestion, and streamline the movement of people and goods. This transportation hub serves as a critical link for both commuters and freight, and the planned upgrades will support smoother traffic flow and shorter travel times, while also benefiting air quality. By addressing these issues, the project will enhance safety for drivers, contribute to economic vitality, and improve the quality of life for San Joaquin County residents, commuters, and businesses alike.

Exploring potential solutions to safety and congestion issues at State Route 99/120 began in the early 2010s. Environmental studies for the project began in Fiscal Year 2016-17.

In this project, the State Route 120 Connector ramp links eastbound SR 120 with southbound SR 99, creating an essential transition for the flow of traffic and goods across the region. The upgrades include adding an additional lane to the ramp, which will enhance efficiency, improve safety, and reduce congestion. These improvements aim to make travel safer and reduce commute times, while also lowering emissions to support better air quality.

After detailed traffic studies, it was determined that congestion relief was most needed on the eastbound SR 120 to southbound SR 99 route, making it a top priority for safety and traffic flow improvements. Deciding against a flyover ramp was based on a review of cost, right-of-way access, and space, carefully evaluated by Caltrans to ensure the most effective and sustainable enhancements for the region.

The project design meets Caltrans standards and no additional curvature will be introduced, ensuring that the ramp remains safe and accessible for drivers, while addressing the project's primary goals of improved safety and traffic flow.

While construction may temporarily affect commutes through lane closures and detours, the SJCOG team is committed to minimizing disruptions. Efforts to limit delays include scheduling construction during off-peak hours and providing advance notice for any required detours. Once completed, these improvements will make commutes safer, smoother, and more efficient by reducing congestion and improving traffic flow.

To find more information and sign up for updates, please visit the Updates page. The project hotline and email address are (209) 209-4690 and 99-120connector@sjcog.org.

Construction began in August 2024 and will continue until summer 2026. It includes constructing and widening surface roads, installing new railroad gates, replacing the Austin Road overcrossing, and adding an additional lane to the State Route 120 Connector ramp. These upgrades will contribute to safer travel, reduced congestion, and support economic and freight mobility in the region. For a stage-by-stage breakdown and timeline, visit the Updates page.

Funding comes from various sources, including Measure K, a local transportation sales tax managed by SJCOG, the State Transportation Improvement Program, Caltrans' State Highway Operation and Protection Program, and federal COVID-19 relief and highway infrastructure funds. These funds collectively support the project’s goals to enhance safety, efficiency, and sustainability in regional transportation.

Yes, the half-mile Singh Street was built to link Austin Road and East Atherton Drive to ensure direct access to Moffat Boulevard without major rerouting once the new, longer Austin Road overcrossing is in place. The street was named to honor a common and well-recognized surname in Manteca and not a specific person.