Alpine will launch a demonstration roundabout project in September at the intersection of U.S.89 and the Greys River Road.

The temporary roundabout is designed to address increased traffic flows within the Town of Alpine and help the community further develop a transportation plan.

A Wyoming Department of Transportation Department sampling of 2026 summer traffic on July 30 showed 3,674 vehicles traveled through Alpine in both directions during one 24-hour period.

The roundabout project is the combined effort of the Town of Alpine, Kimley-Horn Engineering and the Wyoming Department of Transportation. The project is funded with a grant from the Safe Streets and Roads program.

Using the temporary roundabout, the traffic studies are expected to be conducted from the third week of September through the third week of October.

Interim WYDOT Director Darin Westby submitted a letter of support for the project.

“WYDOT supported the grant application with a letter of support and has been involved with reviewing their proposals and designs as a supporting agency,” explained Stephanie Harsha, WYDOT spokesperson. “Since the temporary roundabout will be on the state’s highway system, WYDOT will continue to monitor traffic impacts to US 89 informally, but the formal collection of data and post review will come from Kimley Horn.”

She added, “WYDOT will be looking at how this temporary traffic control layout impacts the state highway system and its efficiency.”

The demonstration roundabout will feature tubular markers and temporary curb  at the intersection of US 89 and Greys River Road.

Similar temporary traffic study projects are underway throughout Wyoming.

Harsha advised, “This sort of ‘temporary’ demonstration project is not unusual to Wyoming and WYDOT, although it has not been done with a roundabout yet.“

Demonstration Projects

Harsha reported on additional demonstration projects in Sheridan and Pinedale.

In Sheridan, WYDOT allowed a similar change with temporary traffic control infrastructure installed to change from four lanes to three lanes.

In Pinedale, a demonstration project is currently in place on US 191 using flexible delineators.

Harsha concluded, “It is a common practice in other states as well to put up temporary traffic pattern changes, as a demonstrations, to introduce the public to the changes and evaluate its effectiveness at a lower cost than complete reconstruction.”

Alpine

“The town council decided a temporary roundabout demonstration project would be the most effective to study,” Alpine Mayor Eric Green said following a review of the project at the latest town council meeting. “The goal  is to try and slow down traffic coming through Alpine.”

“It’s going to be temporary bollards, rubber bumpers, things like that to kind of direct the traffic around,” Green said. The setup will also include an approach designed to divert traffic slightly before it enters the roundabout.

After the demonstration concludes, the temporary striping and equipment will be removed and the intersection’s original striping restored. Green stressed that the project is intended to provide data and public experience—not to commit Alpine to immediate construction.

“This is just a demonstration project, and we’re just trying to study what the effects would be of a roundabout there,” he said. “It’s not going to be permanent in any way, anytime soon.”

If the trial indicates meaningful safety and traffic-flow benefits, a permanent roundabout would still require future planning and funding. “We’re going to have to find federal funding,” Green said, noting that a full project would likely be “many years to come down the road.”