Minnesota DOT testing traffic signal sensor for bicycles in Northfield


As part of its statewide program to encourage sustainable mobility, the Minnesota Department of Transportation (MnDOT) is conducting a pilot study in the City of Northfield to determine the effectiveness of a new traffic signal sensor for bicycles.

MnDOT is working with MS Sedco, an Indianapolis company providing free use of the radar bicycle sensor that is being used at Highway 19 or Second Street at Highway 3, to ensure that bicycles trigger the signal. The radar sensor is designed to detect when a bicycle is waiting, and it will trigger a green light for through passage or a green left turn arrow. The intersection of Highway 19/Second Street and Highway 3 in Northfield is a busy point in the Rice County city that provides one link between the city’s two colleges, Carleton and St Olaf, as well as the downtown and the business community on the west side of the Cannon River. It is the first such bicycle dedicated system used with an MnDOT traffic signal, and the agency’s study will provide information to other agencies and communities on equipment that can be used effectively for bicycle traffic.

The signal to cross Highway 3 or turn onto it does not change until a vehicle approaches from Highway 19 or Second Street. At that time, traffic is stopped on Highway 3 and the side approaches are provided with green lights for crossing or turning. Loops in the pavement detect vehicles to trigger the signal, but not all bicycles were previously detected. MnDOT is analyzing whether the radar detection system will trigger green lights more consistently for bicycles, which provide safe crossing and improved traffic flow. Early indications are that the system is working well, but the agency says further study is needed.

“Part of our objective is to test this system to determine if we can recommend this product to other Minnesota agencies that are looking for bike detection at a traffic signal,” said Jerry Kotzenmacher, MnDOT traffic systems. “To give this recommendation, we must test this system for a duration of time. Users must also understand how a traffic signal works to be able to give feedback to MnDOT.”

MnDOT has worked with BikeNorthfield, a community group, to improve the signal detection equipment with bicycles using the intersection. The agency will use their input on this current project to learn more, and BikeNorthfield is helping educate its community about how the signal detection is used. Eric Johnson of BikeNorthfield, commented, “We’ve been pleased with the new radar bicycle sensor. We’ve been glad to work with MnDOT to offer our feedback in making improvements for bicycles.”

Nancy Klema, MnDOT District 6 traffic operations engineer, noted, “The Northfield bicycle community has been helpful and good partners, as we’ve worked on improving our roadways for bicycles. The knowledge and experience we gain through our work with them has helped us provide information and lessons learned to others in the state.”

Share this story:

About Author


Tom has edited Traffic Technology International (TTi) magazine and its Traffic Technology Today website since May 2014. During his time at the title, he has interviewed some of the top transportation chiefs at public agencies around the world as well as CEOs of leading multinationals and ground-breaking start-ups. Tom's earlier career saw him working on some the UK's leading consumer magazine titles. He has a law degree from the London School of Economics (LSE).