Manteca is ground zero for new interchange construction in the Northern San Joaquin Valley.

This year will see three actual physical interchange projects get started or completed.

*The new McKinley/120 Bypass interchange will be completed by the end of spring.

*Work will start on the demolition of the Austin Road/Highway 99 interchange and the replacement four-lane overpass that will also clear the railroad tracks.

*The first phase of a three-phased upgrade of the 120 Bypass/Highway 99 interchange will start with the addition of a second southbound transition lane toward Modesto.

And, if Mayor Gary Singh, has his way, the ball will get rolling faster this year toward a fourth interchange project to come on line — an upgrade of the Airport Way/120 Bypass interchange.

“There is money that will be left from the McKinley interchange that I hope to get put toward Airport Way,” Singh said.

The city’s goal is to repeat what they did at Union Road when California’s first diverging diamond interchange opened almost three years ago with the interchanges at Main Street and Airport Way.

It will also include a separate bicycle/pedestrian bridge to maximize safety.

The advantages of the diverging diamond interchanges is they do not require the taking of additional land, the exiting bridge decks can be utilized, they reduce the number of opportunities for T-bone collisions, and they allow for faster traffic flow.

They also cost less to build and take less time to construct.

Singh confirmed this week Congressman Josh Harder has secured an additional $500,000 to help fund the second phase of the 99/120 interchange work.

That basically consists of a second transition lane from northbound Highway 99 to the westbound 120 Bypass.

That leaves a $5 million funding gap Singh and others are working to cover.

If that happens, once phase one is completed work will immediately start on the second phase.

The mayor is working with staff to develop a growth fee on future growth in a set benefit area to advance to the council for their consideration in a bid to help fund the third phase.

The $60 million phase will include restoring the ramps on the northside of the new Austin Road interchange with elaborate braided maps for safe and optimum traffic `movement.

It also will involve widening the 120 Bypass to six lanes between McKinley Avenue and Highway 99.

Singh noted it is feasible that the Highway 99/120 Bypass interchange will be a continuous construction zone for nine to 10 years.

The mayor said that is better than a gap of numerous years between phases.

The city is also gearing up to pursue plans — and funding — for a new interchange on Highway 99 midway between French Camp Road and Lathrop Road.

It will serve the Roth Road extension.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com