A plan being pursued to alter the phased approach to the 120 Bypass/Highway 99 connector project will help open a large swath of southeast Manteca for the development of employment centers.

The new Austin Road interchange currently being built will be a full interchange in the project’s second phase instead of waiting for a third phase that funding may never be secured to build.

Originally, the northbound on-ramp and south bound off-ramp were going to be “temporarily” closed at the end of the current phase and then restored with elaborate braided ramps in the third phase.

Efforts underway now that have been heavily advocated by the City of Manteca would install new replacement ramps in the second phase that is tentatively targeted to start in four years.

The centerpiece of the second phase is adding a second transition lane from northbound Highway 99 to the westbound 120 Bypass.

As it is now being planned, the second phase will include restoring the two ramps on the north side of the Austin Road interchange.

Given how the replacement overcrossing now being built was designed to add additional lanes on Highway 99, a deacceleration lane on southbound Highway 99 would start north of the bridge.

It would feed into the off-ramp that would then curve back and flow directly onto Moffat Boulevard heading north.

As such, it would be similar to the southbound off-ramp to Pelandale Avenue in Modesto.

The southbound on ramp to Highway 99 will stay as it is with southbound Moffat tying directly into it.

The southbound off-ramp, after curving back to the north, will be the start of northbound Moffat.

There would be no streets or driveways until it reaches the new Woodward Avenue/Moffat intersection now under construction to allow a 90-degree crossing of the railroad tracks.

The new intersection will have traffic signals.

The design would eliminate concerns about exiting traffic backing up onto the freeway.

The northbound on-ramp would join the outer lane of the two lanes that will transition to the westbound Bypass.

The current ramp, which is extremely problematic to use it to head north toward Yosemite Avenue, merges with Highway 99 before the current 120 Bypass transition ramp.

The second phase would make the 120 Bypass three lanes in each direction from Airport Way to Highway 99.

The new approach to the second phase would increase the price to $80 million or so.

There has been roughly $50 million identified.

The city is proposing forming a community facilities district encumbering future development benefitting from a full interchange to help cover much of the gap. Such a plan may require shifting road funds that would be paid back with the CFD collections.

The original projection that was the third phase wouldn’t start until at another 10 years or so to allow the preferred longer, braided ramps.

Given funding issues that likely will add even more time and make the third phase as originally designed even more expensive, the odds are it might never happen.

That doesn’t mean it is off the table.

The funding for the two braided ramps as they were designed was a daunting challenge given it would cost more money than building an entire standard interchange from scratch.

The plan as now structured means there is a clear and do-able path to Austin Road being a full interchange sooner than much later.

The current phase is adding a second transition lane from the eastbound 120 Bypass to southbound Highway 99.

It will also have three lanes from the Main Street interchange to Highway 99 given the bridge crossing of Moffat Boulevard and the railroad tracks can already accommodate three lanes.

Regional impacts

on the economy

The new second phase does two things.

It avoids creating significant traffic circulation problems as southeast Manteca grows given use of the interchange by current and future residents would be limited.

Not only would it be worthless without the two mentioned ramps to go to and from areas in Manteca that can be accessed quicker by freeway than surface streets, but an estimated 90 percent of the commuters in Manteca head west to Lathrop, Tracy, and the Bay Area for jobs.

That means even if they are within blocks of the new Austin Road interchange, without the two ramps they would be forced to travel to on-ramps at either Yosemite at 99 or Main at the Bypass to go to and from work.

Mayor Gary Singh, though, noted the biggest plus for Manteca and the region would be unlocking the potential of the 1,080-acre Austin Road Business Park and nearby land yet to be zoned for employment centers and other uses.

When the site was being shopped around in 2010 as  it was going through the approval process, it quickly got the attention of a number of major firms due to it being on the Highway 99 corridor with a connection to the 120 Bypass to reach Interstate 5 as well as Interstate 205 to the Bay Area.

The project zoning was approved but it got bogged down in the need to upgrade freeway access.

The Austin Road interchange built in 1955 with its at-grade rail crossing and limited capacity bridge was a big issue.

That led to the proposal for the Raymus Parkway interchange that would align with Olive Avenue in Ripon. The cost of such an interchange was pegged at almost $90 million in 2010 as it would requiring shifting Highway 99 to make it work as well as bridging the railroad tracks.

The push to upgrade the Highway 99/120 Bypass connector that started in 2016 changed the planning board.

Originally, Caltrans wanted to eliminate all of the ramps due to the close proximity of the 120 Bypass and Austin Road interchanges to each other on the Highway 99 corridor.

The city pushed successfully for that not to happen.

Instead, it was decided to tear it out and replace it with a new two-lane overcrossing. The city added $8 million of its own money to oversize it to four lanes to accommodate growth.

The San Joaquin Council of Governments that is overseeing the project, has been using the proverbial monkey wrench tossed into the initial work by Union Pacific Railroad declining to allow the placement of a bridge support column in their right of way, to rethink the project in a bid to secure the best outcome.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com