Work is well underway on the Austin Road replacement bridge that will allow the widening of Highway 99 to accommodate a second transition lane from the eastbound 120 Bypass heading toward Ripon.

Construction of the first phase of what will eventually be a three-phase, $150 million upgrade to improve traffic flow through the 120 Bypass/Highway 99 interchange is being overseen by the San Joaquin Council of Governments.

The initial phase does more than just add a second southbound transition lane to Highway 99 from the 120 Bypass.

It is significantly transforming city street flow in southeast Manteca while further setting the stage for future development.

It will:

*Widen Woodward Avenue to four lanes between Moffat Boulevard and Atherton Drive. In doing so, it will be in an alignment that allows a 90-degree crossing of the railroad tracks where there will be crossing signals similar to what is on the Industrial Park Drive crossing. It will be tied into traffic signals at Moffat and Woodward.

*Eliminate the at-grade railroad crossing on Austin Road as well as a four-way stop at Moffat and Austin.

*A connector road that was named Singh Street connects Atherton Drive to Austin Road. It will serve as part of the route traffic on Moffat or Woodward will use to access the replacement bridge to reach the east side of  Highway 99.

The new alignment of Woodward and the elimination of the Moffat/Austin intersection means the afternoon traffic backup of people bypassing the 120 Bypass will be eased.

It makes turning onto Moffat safer.

The elimination of the Austin/Moffat intersection coupled with the fact the Highway 99 southbound off-ramp will temporarily be closed for at least 10 years until the third phase of the project is completed means once traffic turns onto Moffat heading south it will have an uninterrupted path to the Highway 99 freeway.

The new four lane bridge crossing both the tracks and Moffat is expected to set the stage for growth in southeast Manteca.

The city has 1,050 acres zoned to accommodate more than 4,100 homes as well as a 600-acre business park.

The city contributed $8 million so the replacement bridge would be four lanes instead of two lanes.

Manteca will need to come up with most of the funding for the third phase which will restore the southbound offramp and northbound onramp at Austin Road with long braided ramps to allow for optimum traffic flow.

The southbound offramp will start, for example, before the 120 Bypass crossing of Moffat Boulevard as well as on the northside of the 120 Bypass/Highway 99 interchange.

They also are designed to accommodate truck movements, a key factor for Manteca given the city wants to develop a business park in the southeast portion of the city.

The first phase is expected to be completed in mid to late 2028.

The second phase will add an additional transition lane from northbound Highway 99 to the westbound 120 Bypass.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com