Ground is breaking in the coming months for the first phase of the major overhaul of the Highway 99-120 Bypass but the hunt is already on to fund the next phase.

The San Joaquin County Board of Supervisors included the interchange work when they adopted the top 10 list of pressing road projects that will be used to pursue federal and state money to augment revenue from the Measure K half cent sales tax.

The first phase — a $51.6 million endeavor that adds a second transition lane from the westbound 120 Bypass to southbound 99, replaces the Austin Road interchange, and reconfigures segments of Woodward Avenue and Moffat Boulevard — is on target to break ground this spring.

If all goes well, work on the first phase of the project would be completed in winter of 2023.

The second phase costing $28.1 million involves widening the 99 northbound transition lanes to two. Doing so would require a new eastbound 120 to northbound 99 ramp and bridge across Highway 99.

The current ramp and bridge would be converted to two lanes heading west by removing the median barrier on the existing ramp.

The second phase’s final design is expected to be completed in the spring of 2024 with construction underway by summer of 2024, and work completed by the fall of 2025.

The third and final phase would include braided ramps for southbound traffic on Highway 99 and eastbound traffic on the 120 Bypass to exit at Austin Road and a braided ramps for traffic from Austin Road headed north on Highway 99 and west on the 120 Bypass.

Other top priority roadwork includes:

  • Adding managed lanes on Interstate 205 as either high occupancy vehicle lanes or bus lanes.
  • Improving 11th Street from Tracy to Interstate 5.
  • Upgrading Grantline Road from Kasson Road to the Tracy city limits.
  • Improving a segment of the Escalon-Bellota Road north of Escalon.
  • Upgrades to Highway 12/Highway 88 east of Clements.
  • Lower Sacramento Road railroad crossing improvements between Stockton and Lodi.
  • Upgrades to the Byron Highway (State Route 239).

The list also includes a countywide autonomous vehicle testing program.