New overpass being built on Highway 46 East

About 60 workers maneuvered with a practiced precision among steel-and-wooden bracings 100 feet in the air as they poured concrete recently for the Highway 46 East widening project’s new westbound overpass.

Since February, crews have been tackling the $72 million second phase of work to expand the highway from Geneseo Road to Almond Drive near Paso Robles. The file-mile stretch will go from two lanes to four.

The widening project is designed to increase safety on the popular corridor that connects the Central Coast to the San Joaquin Valley.

Its financing comes from Proposition 1B, a $20 billion transportation bond measure approved by California voters in November 2006.

Big changes include the new eastbound and westbound bridges, each about 1,000 feet long. They will tower over the Estrella River and a stretch of existing highway that motorists have used for 50-plus years, which will soon become a frontage road.

The overpasses will replace that section of highway, an aging bridge and a steep western slope near the riverbed in the Whitley Gardens area just east of Paso Robles.

“The final route is located above the existing Highway 46,” said Ramon Hopkins, a Caltrans senior engineer.

The first bridge will have three new lanes going west, including a merging lane on the right for vehicles entering the highway at Whitley Gardens. The second bridge will have two new lanes going east.

Much of the westbound bridge is already erected, with its concrete deck expected to be finished within one month. Stamped concrete columns stand just south of it, ready for the eastbound bridge construction to begin in about two months as the westbound bridgework wraps up.

Both overpasses are expected to be complete by April 1, engineers say.

Some rerouting and filling in of the old highway with rock and landscaping will be done as well.

Big-rig trucks and cars whooshed past the new westbound bridge last week as they traveled on the original overpass that stands piddly in the new span’s shadow.

In April, Caltrans will detour traffic to one of the new bridges through a temporary road cut through the hills just east of Union Road that crews paved in July.

The detour will give crews time to demolish the old highway just east of Tobin James Cellars to the bridge area and fill the space with material cut from the hillsides.

With the old route gone, the new corridor should appear seamless once landscaping is done.

“We’ll reseed the native grasses and shrubs and round out the hills,” Hopkins said. “Ten years down the road, the hope is you’ll never know this (rerouting) has been done, but that we just fit the road to the natural terrain.”

The project at a glance

The first phase — from spring 2008 to this summer — widened five miles of Highway 46 East from Airport to Geneseo roads. Fresh native landscaping will be planted in that area in October.

The second phase of work, going on now, is to be completed at the end of 2013.

The third phase will widen the highway near Shandon from Almond Drive to McMillan Canyon Road. It’s expected to start in fall 2012, with utility preparations beginning as early as January.