Barriers will go up the morning after Memorial Day on County Route 458 as construction begins on the season’s big Douglas County Public Works road improvement project.

Keith Browning, Douglas County public works director, said contractor King’s Construction, of Oskaloosa, will start the first phase of the $6.6 million project to improve a 4.5-mile section of CR 458 on May 30, weather permitting. Federal funding through the Kansas Department of Transportation will provide $3 million of that total.

The section of CR 458 to be improved stretches from East 800 Road north of Lone Star east and north to near its junction with North 1150 Road. Work will include replacement of undersized culverts, installation of paved shoulders, pavement resurfacing and flattening of roadway slopes. Three 40 mph curves on the section will be altered to accommodate 55 mph traffic. The project area is the only section of CR 458 west of U.S. Highway 59 without the upgrades.

The project will be completed in four phases, Browning said. The first phase involves the replacement of a number of narrow culverts and the realignment of the three curves in the project area, he said.

Phase 2 will involve replacement of five additional culverts and paved shoulder installation on the south and east sides of the route.

Culvert replacement during Phase 1 and into Phase 2 will necessitate closure of the road to through traffic, said Chad Voigt, deputy public works director. For the convenience of residents, culvert replacement will be done in sections so that the whole project area would not be closed at one time, he said.

Culvert replacement should take about four months, depending on weather, Browning said. A signed detour will be established that follows U.S. 59 south to U.S. Highway 56 and west to County Route 1029.

Once all the culverts are replaced, the project area will be open to two-way traffic on two narrow lanes. Browning said. The speed limit will be 35 mph and bicycle traffic will banned during the project’s duration, he said.

Phase 3 includes paved shoulder installation on the north and west sides of the project area, Browning said. The final phase includes asphalt overlay of the entire route, installation of pavement markings and seeding.

If all goes well and weather cooperates, King Construction could compete the first two phases during this construction season, but some of Phase 3 may have to wait until spring 2018, when Phase 4 is scheduled, Browning said.

“We should be finishing up with the project about this time next year,” he said.

The public can visit www.facebook.com/Route458 to stay apprised of project details and progress, Browning said.