Road crews on Monday were to close a busy stretch of 9000 South for much of this year's construction season.

As part of its efforts to unclog traffic jams in the southern part of the suburban Salt Lake Valley, the Utah Department of Transportation is widening the commuter boulevard from two lanes to five between State Street and 150 East.The project will double the street's hourly capacity from 3,000 to 6,000 vehicles, but motorists are advised for the time being to detour the work via 9400 South.

Monday's closure will last for six weeks as crews relocate utility lines. Its reopening in mid-April will be shortlived, however. Later this spring, UDOT will shut down the same spot again - for up to eight weeks - to rechannel an irrigation canal.

The project compounds ongoing headaches for commuters who are used to accessing I-15 via 9000 South. UDOT is currently widening the street between Redwood Road and 4000 West, causing traffic bottlenecks on the west side of the freeway, too.

But highway officials say motorists will benefit in the long run.

"It's going to greatly improve east-west traffic flow," said Carlos Braceras, UDOT's roadway design engineer for the area.

Braceras said the work will eliminate many "conflict points" along the road, making it safer and faster. He said the project is a "major component of the valley's transportation system" and will be an important park-and-ride locale for the proposed light-rail line the Utah Transit Authority is building between Sandy and downtown Salt Lake.

Plans are to eventually extend the expansion to 700 East. The road, once rebuilt, will have five lanes, including a center turn lane, plus curb and gutter.