This is an archived article that was published on sltrib.com in 2011, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Driving onto Bangerter Highway from State Route 201 after this weekend may have you feeling like you've momentarily been detoured to Great Britain — a land where cars drive on the left side of the road.

The Utah Department of Transportation will unveil Salt Lake Valley's first "diverging diamond" interchange Monday morning at SR 201 and Bangerter Highway in an attempt to accommodate increased traffic flow due to expansive growth in the western portion of the county.

Beginning Friday at 11 p.m., UDOT will close the interchange and it will reopen Monday at 5 a.m.

Once it's open, drivers will face what UDOT officials call an "intuitive interchange." Essentially, motorists heading eastbound on SR 201 and exiting north onto Bangerter will find themselves crossing the bridge. At that time, the driver looking to the right will feel as though his or her car is on the wrong side of the road. But then the interchange will sweep back to the right side of the road at the end of the bridge.

Tim Rose, region two director for UDOT, said it may be a little disconcerting at first, but the design keeps the cars flowing where they're supposed to instead of putting drivers at risk.

"It is very intuitive," he said. "I am very confident it will work."

The $10 million diverging diamond interchange looks like a double helix from an aerial view and it eliminated a left-turn arrow for drivers merging from SR 201 to Bangerter. Rose said rebuilding the interchange under the old configuration would've cost $40 million and that it still wasn't designed to handle the volume of cars that use that stretch of road.

He said the new interchange will be able to accommodate the daily traffic volume of 100,000 vehicles per day and the anticipated growth of 10 percent more cars over the next eight years.

It's the third diverging diamond interchange in Utah. The first opened at Main Street and I-15 in American Fork in 2010, and the second opened earlier this year at I-15 and Timpanogos Highway in Lehi.

UDOT officials said the new interchanges are more cost-effective.

The first diverging diamond interchange was opened in Springfield, Mo., in 2009.

Angela Eden, spokeswoman for the Missouri Department of Transportation, said there was some skepticism when the state planned its first diverging diamond interchange. But she said since it's been in place, it's resulted in fewer accidents and better traffic flow.

Still, she said not everyone has come around.

"There is no middle ground," Eden said. "People either love it or they hate it. But it seems the loves far outnumber the hates because people aren't backed up in traffic."

Eden said the reason for diminished accidents — and no head-on collisions since it was put in place — is because there is no longer a left-turn arrow people are trying to beat.

Rose said the removal of a left-turn arrow and just having the green light in place for left-turn traffic onto Bangerter will be a key component to reduce those types of accidents.

The project began in August, and Rose said while it will be open and operational beginning Monday, the landscaping and cleanup of the interchange won't be finished until early November.

dmontero@sltrib.com

Twitter: @davemontero