MONTANA CITY -- All went pretty smoothly Tuesday afternoon as drivers piloted themselves through the new roundabout at Montana City.

"I'm watching it. Some humorous things are happening," said Joe Calnan, who was looking down on the roundabout from his upstairs office window at the Montana City Store Wednesday morning.

For the uninitiated: A roundabout is a road junction with an island in the middle around which traffic flows in the same direction.

The new roundabout is at at the intersection of Highway 282 and Highway 518, just west of the Montana City I-15 overpass.

"For the most part it's working well, Calnan said. He had just watched an Ash Grove Cement truck move through it successfully.

There had been concerns expressed at public meetings that trucks could have trouble negotiating through the new intersection, he said.

"It's probably a little early to pass judgment on it," Kelvin Gebhardt, temporary quarry supervisor at Ash Grove, said Wednesday.

Although the roundabout is open, it isn't completed, said Charity Watt Levis, public information officer for Montana Department of Transportation.

The contractors still have to pour concrete in the center island and the truck apron, which trucks use as they maneuver through the roundabout.

Medians still need to be installed as well as landscaping. Weather permitting, these should be done by Nov. 1.

This is the second roundabout installed by MDT in the state, Watt Levis said.

The first was in Kalispell. Some Montana communities have also installed them, she added.

One benefit of roundabouts is that they reduce the severity of crashes, she said. And they should eliminate dangerous, T-bone crashes.

According to the Federal Highway Administration, roundabouts reduce injury accidents by 76 percent and fatalities by 90 percent.

They also reduce pedestrian injuries by 40 percent.

One reason accidents are less severe is that vehicles are forced to slow down as they enter the roundabout, Watts Levis said.

"It also moves traffic better," she said. "You don't have to come to a complete stop. You're not stopping at an intersection, and no one is there."

And they save approximately $5,000 annually per intersection in traffic signal maintenance and electricity, she said.

"We're grateful for everybody's patience (during construction)...but in the end we're getting a great intersection," said Watts Levis.

How to navigate a roundabout

1. Slow down to 15 mph or less.

2. Look to the left.

Traffic flows counterclockwise. Yield to vehicles in the roundabout -- they have the right of way.

3. Stay to the right of the center island.

Do not stop, and do not pass other vehicles.

4. Travel around the circle until you reach your turn. Use your right-turn signal.

5. Watch for and yield to pedestrians in or waiting at the crosswalk.

-- Source: Montana Department of Transportation

Reporter Marga Lincoln: 447-4074 or marga.lincoln@helenair.com.