Intersection Safety Case Study Summary

FHWA-SA-09-013

Minnesota Roundabout

A Scott County Success Story

The Challenge

• The intersection of State Highway 13 and County Road 2 in Scott County, Minnesota, was the site of 2 fatal crashes and 50 injury crashes between June 2000 and June 2005.

• Minnesota Department of Transportation (Mn/DOT) tried several treatments, including larger stop signs, striping, and flashing lights, with little success.

• Mn/DOT sought to reduce the number and severity of crashes at this two-way stop-controlled intersection.

Solution

Single Lane Roundabout:• 4 approach lanes• 1 circulatory lane• Central Island diameter of 110 feet • Approach lane widths of 16 feet• Departure lane widths of 14 feet• 200-foot long median on County Road 2• 300-foot long median on State Highway 13• 25 feet wide splitter islands• 10 feet wide truck apron• Transverse rumble strips placed 20 feet

center-to-center on apron

Technical Data

• Location:– County Road 2 and State Highway

13, Scott County, MN

• Speed Limits:– Both County Road 2 and Highway 13

have a posted speed limit of 55 mph

• Average Daily Traffic (ADT):– County Road 2 - 4,300– Highway 13 – 4,650

• Construction Cost:– $725,000

• Construction Time:– Constructed in 2005 and lasted for

3 months

• Implementation Issues:– MnDOT experienced no

implementation issues withthe roundabout

Results

• Average Crash Reductions:

– 100% reduction in angle crashes per year

– 78.7% reduction in injury crashes per year

– 76.2% reduction in total crashes per year

For More Information

• Visit FHWA’s intersection safety web site to download this and other case studies highlighting proven intersection safety treatments from across the country:

http://safety.fhwa.dot.gov/intersection/

• Or Contact:

Ed RiceOffice of Safety (HSSD)Federal Highway Administration

Phone: (202) 366-9064E-mail: ed.rice@dot.gov

Anthony J. Winiecki, P.E., PTOEScott County Public Works Department, Jordan, MN

Phone: (952) 496-8346E-mail: twiniecki@co.scott.mn.us