Safety Success: Marion County Roundabout Improves Safety, Reduces Crash Severity at Rural Intersection

A roundabout constructed in 2022 at the intersection of State Route 98 and State Route 529 in Marion County has proven to be a success. New data shows a significant drop in crash severity and frequency since the roundabout opened to traffic in Fall 2022.

According to post-construction crash statistics, the site has seen zero injury or fatal crashes since the roundabout became operational — a marked improvement over previous years.

Prior to the roundabout’s construction (2018 through July 1, 2022), there were 37 total crashes at the intersection, 65% being angle crashes and nearly 60% of the total crashes resulting in injury. Since the roundabout opened, the average number of crashes per year has decreased, and the types of crashes have shifted from high-impact collisions to less severe roadway departures.

“Safety is our top priority, and this roundabout is doing exactly what it was built to do — slow down traffic and prevent serious crashes,” said ODOT District 6 Deputy Director Anthony Turowski. “We’re proud of these results and proud to support a community that believes in smart, safe improvements.”

Roundabouts are widely recognized as one of the most effective tools for reducing crashes at intersections. Unlike traditional intersections, which have 32 potential conflict points where vehicles can collide, roundabouts reduce that number to just 8. This dramatically lowers the chances of both angle and head-on crashes — the types most likely to result in serious injuries or fatalities.

According to studies by the Federal Highway Administration (FHWA):

• Roundabouts reduce total crashes by 44% and serious injury or fatal crashes by nearly 90% when replacing a two-way stop intersection.
• When replacing a traffic signal, roundabouts result in a 48% reduction in total crashes and nearly 80% fewer serious or deadly crashes.

In February 2023, additional signage improvements were made to further enhance driver awareness, including advanced warning signs and 20 mph advisory speed plaques leading up to the roundabout.

At rural intersections, there are often concerns about how large farm machinery or semi-trucks will navigate roundabouts. This is accomplished with truck aprons – an area between the central island and the traveled way – that is mountable by larger vehicles but not used by passenger vehicles.

For more information on roundabouts and to view videos on how to properly navigate them, please visit www.transportation.ohio.gov/roundabouts.