Buyers of new homes in Manteca have covered the tab for the city’s share of the nearly $50 million price tag for the first phase of the 120 Bypass/Highway 99 upgrades.

The work adding the second transition lane from the eastbound 120 Bypass to southbound Highway 99 and the replacement of the Austin Road interchange is expected to be completed by year’s end.

The city’s share of the project is $3.2 million.

It reflects the cost of widening the replacement interchange from two to four lanes for capacity to serve development of the 1,080- acre Austin Road Business Park in southeast Manteca that includes zoning for housing up to 10.500 people.

Manteca’s Council is being asked to authorize covering the cost with Regional Transportation Impact Fees assessed on growth that is already on hand to pay for infrastructure of a regional nature.

State highway funds paying for the bulk of the overall 120 Bypass/99 project can’t be used to fund growth inducing in improvements.

Currently — and in the near range — traffic didn’t justify a four lane replacement overpass.

Previous city councils — under the leadership at the time of then Mayor Steve DeBrum and the. Mayor Ben Cantu — pushed for the four lane replacement overpass.

They did so we the belief that within 10 years or so of its completion, a two-lane bridge based on development patterns and approved project would require the bridge to be widened at a significantly higher cost.

The replacement bridge in clearing the railroad tracks as well plus the operational improvements the two-phase freeway upgrades will put in place is expected to resolve truck movement issues the original interchange at Austin Road and 99 presented.

Proposed fees on growth south of the Bypass are envisioned to cover the local costs of ramp replacements in the second phase of the project.

That includes traffic from Austin heading north on 99 would use a ramp that would curve under the overpass.

Traffic existing at Austin from southbound 99 would do so on a ramp that goes under the overpass and curves back to connect with Moffat and use surface street improvements the state-funded project is covering to reach Austin Road.

The under-the-overpass ramps effectively eliminated the third phase that was envisioned to have elaborate braided ramps — including one where eastbound 120 Bypass traffic needing to exit at Austin Road by entering a ramp starting just past Main Street costing in excess of $50 million.

Had a redesign not occurred, the third phase would have required the city to come up with the money for the replacement ramps all in its own.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com