Prosper to consider using roundabouts instead of traffic signals on future roads

Prosper residents could see more roundabouts on future roadways as town officials consider implementing a new policy to guide their usage.

Prosper Town Council members discussed the town’s potential roundabout policy at a March 24 work session.

What you need to know

Prosper’s Engineering Director Hulon Webb said several roadways in Prosper that are slated for future construction could be candidates for roundabouts. Some roadways could have interim roundabouts, while others may be permanent.

“Somewhere in the future, the [new] policy would be if an intersection along that stretch of road requires us to go through a signal warrant, we would also evaluate a potential roundabout,” Webb said.

Town staff previously identified several intersections throughout Prosper that could be suitable for a roundabout, primarily focusing on intersections controlled by Prosper and roadways that would not eventually turn into six-lane roadways.

Webb said the town is considering interim roundabouts on roadways that are ultimately planned to expand to six lanes, so the roundabouts can be removed later once “the time comes to make those roads six lanes.”

Roundabouts would only be considered for projects still in the design phase or not yet designed, Webb said. Any roadways already under construction would not be affected.

How we got here

Council members first discussed the policy at a Feb. 10 meeting, when a representative from engineering and design firm Kimley-Horn presented on the benefits of roundabouts.

Roundabouts are generally considered safer and result in fewer crashes, while traffic signals are more prone to T-bone crashes, the representative said. Additionally, while traffic signals are cheaper to install, they require more annual maintenance costs than roundabouts, per the presentation.

Webb said adding a roundabout to a roadway project could cost about $1.2 to 1.5 million per intersection.

The discussion

Town Council members generally agreed that roundabouts should not be used on fully built six-lane roadways.

However, they supported evaluating interim roundabouts along Prosper Trail at Legacy Drive and Teel Parkway, as future road improvements for Prosper Trail have not been fully designed yet.

Mayor Pro Tem Amy Bartley supported looking at adding roundabouts on Prosper Trail, particularly near the intersection with Legacy Drive, as she said she’s more concerned about the current and future traffic, primarily due to the residential development there.

Council also discussed the benefits and costs of three-leg roundabouts versus four-leg, which Webb said would cost about the same.

“To me, it still keeps the traffic flowing,” Mayor David Bristol said.

Next steps

Town staff will work to finalize a policy for evaluating potential roundabout locations in Prosper, as well as a map for the town’s design standards.