The days of a four-lane Highway 99 freeway through Manteca are numbered.

Caltrans put the Arch Road to 120 Bypass portion of a 13.1 mile freeway widening project out to bid Monday. Bids will be opened Feb. 28 with work targeted to stay on a spring groundbreaking schedule.

When the overall project is completed in 2015, Highway 99 will be six lanes from Lodi to south of Turlock.

Initial work starting in the spring will add a third lane in the center divider in each direction. The second phase is a new interchange at French Camp Road while the third phase involves a new interchange at Lathrop Road. The fourth and final phase is landscaping.

The $496 million project will not only increase the capacity and improve traffic flow on Highway 99, but it will have a major impact on business as well traffic movements in Manteca along the Lathrop Road and North Main Street corridors.

The new Lathrop Road interchange means the flyover onramp will be removed and the existing Lathrop Road interchange replaced.

It will wipe out at least five businesses including an appliance firm’s warehouse, a gas station, a trailer sales, a multi-tenant business building backing up against the existing overpass and a modular home sales lot. Altogether, 24 properties will be impacted.

Most of the impacted property is on the western side of the freeway. It is the result of the need to extend Main Street north to tie into the south on and off ramps at the interchange.

The interchange will:

• realign the West Frontage Road through Delta College’s property in the northwest corner of the interchange and align it with Crestwood Avenue. Delta College is proposing developing 350,000 square feet of retail on the land.

• extend North Main as four lanes from Northgate Drive to tie into an intersection with the southbound on and off ramps at Lathrop Road. The road, designed to allow traffic to travel at 35 mph, would wipe out several older homes used for commercials purposes, the warehouse portion of Center Appliance and the small business complex built a few years ago between the existing curve and the overpass.

• provide a direct route for trucks accessing business and industrial parks that exist and are proposed between Lathrop and Manteca along the Airport Way corridor. It would also provide a direct truck route between Interstate 5 and Highway 99 in addition to the Highway 120 Bypass and French Camp Road.

• eliminate the modular home and trailer sales businesses on the southeast corner to accommodate northbound off and on ramps.

• relocate the East Frontage Road further east and extend it south of Lathrop Road behind developed parcels before curving back to the existing Frontage Road to provide access to Southland Road.

The state is picking up $282.4 million of the tab from Proposition 1B bond proceeds while the Measure K – the countywide half cent sales tax – is covering the rest of the cost. If it weren’t for the Measure K sales tax San Joaquin County in all likelihood would not have secured the state bond money.