Single-Lane Roundabout Reduces Historical Crashes and Mitigates Rush Hour Congestion
In order to minimize congestion, slow vehicle speeds and address safety concerns at an existing two-way stop-controlled intersection at Norton and Johnson Roads, the Franklin County Engineer’s Office partnered with OHM Advisors to complete a single-lane roundabout improvement design. Although this southwestern Franklin County intersection was not ranked as a safety priority location on the Ohio Department of Transportation’s (ODOT) Safety Analysis list, it was the County’s highest-ranking unimproved intersection. For years, injury-related crashes were a continuous problem due to high speed along Norton Road and inadequate gap space during peak times for vehicles on Johnson Road to maneuver through the intersection.
Prior to designing the solution, our team supported the County’s public engagement campaign with local residents in order to collect their valuable feedback and insights. With the results, our team created a roundabout design in close coordination with Franklin County, the City of Columbus and ODOT District 6 to reduce congestion and slow traffic. Since the project is located within the Big Darby Creek Watershed, we ensured that the project met all requirements related to preserving the watershed area, and designed vegetative bioretention basins (“bioswales”) to allow the post-construction stormwater to recharge into the groundwater at the same rate as the pre-construction conditions.
According to the Franklin County Engineer’s Office, there were no accidents reported at this intersection in the first full year since the project’s completion.
Project Highlights: transportation engineering, surveying, right of way, landscape architecture
In 2015, the intersection of Norton Road at Johnson Road was the highest-ranking unimproved location on Franklin County’s top ten unsignalized intersection list. Roundabouts have proven to reduce speeds and increase safety at high speed intersections, and the post-construction crash statistics reflect that. This critical improvement project is another important step in our Vision Zero journey to eliminate all roadway related deaths and severe injuries.