A “Peanutabout”? – New Design Calms Traffic at Odd Intersections

You’ve heard about a roundabout, but a “peanutabout”?

Beech Grove, Indiana, is the latest location for the new traffic-control alternative that is shaped like a peanut, also called a “peanut roundabout.”

It has the same function as a circular roundabout – to move traffic smoothly and safely without traffic lights and stop signs – but it comes in a different shape due to certain circumstances when a traditional roundabout won’t work.

Traditional roundabouts work best when all intersecting roads are at 90-degree angles. But in cases where the intersecting roads are skewed at different angles, the circular design won’t work. Instead, engineers have designed circular roundabouts for each of the two sections with the skewed-angle streets, rather than one central circle, and then connect them together. The peanut shape also requires drivers to continuously turn, which causes them to slow down. It essentially functions the same as a traditional roundabout.

In the Beech Grove case, the intersection of Churchman and Perkins avenues has “two closely placed, offset intersections where nearby streets cross a highly traveled, skewed road,” says Brian Craig, engineering manager with GAI Consultants, which designed the peanut roundabout.

The design consists of “two standard roundabouts merged together with a connecting middle section,” according to Craig. Part of a roundabout will be on either end of the two skewed intersections.

gray line design of peanutabout for Beech Grove IndianaThe design of the peanutabout planned for Beech Grove, Indiana, by GAI Consultants.GAI ConsultantsThe intersection has seen a high rate of crashes as drivers from intersecting Perkins and Southern avenues try to cross or enter traffic.

Craig describes the current intersection as “two triangles coming together in a somewhat skewed way – with an extra crossing street added in just to make things especially challenging.”

The peanut roundabout will calm traffic but without having to realign the streets, he says. The city received a $1,053,000 federal grant to build the peanutabout.

It joins several other transportation agencies around the country that have used the new design.

Ohio got its first peanutabout in 2022 in Kingston Township.

“The innovative application of a peanut roundabout at this intersection significantly improved the safety of the high-crash location without impacting adjacent properties while accommodating the public’s concerns over maneuverability,” according to Burgess & Niple, a subconsultant on the project, which was designed by Ohio DOT District 6. 

New Haven, Connecticut, and Jackson County, Michigan, have also built peanut roundabouts at dangerous, oddly configured intersections.

The City of Raleigh, N.C., is considering a peanut roundabout for its $20 million Lake Wheeler Road Improvement Project to calm traffic.

Ahead of Beech Grove’s peanutabout project, Mayor Dennis Buckley said he was glad to see relief coming to the crash-prone intersection in his city.

“There’s nothing wrong with stepping out of the box and considering new designs,” he says. “What I wanted to do is slow the traffic way down … and I think this approach hits it head on.” 

Watch a video of how a peanutabout works by Urban Engineers, based in Philadelphia: