Rumble Strip Science

 

 There's a series of rumble strips on the road east of us where Roseau County 8 meets Minnesota State Highway 89. The closest strips are about half mile from our place so we can hear them go blaaat! when a vehicle runs over them as it approaches the stop sign. Fortunately, traffic is light on County Road 8 and if the rumble strips prevent even one accident, then I need to curb my annoyance at the noise.

 Whenever Teresa or I approach rumble strips we try to avoid them because we don't like the noise. I've always wondered what percentage of drivers avoid the strips and what percentage run over them. Instead of just speculating, I decided to take a sample of vehicles on 8 headed east to 89 for a least one hour during morning rush hour. 

   When I told fellow Wannaskan Almanac writer Joe Stenzel (Word Wednesday) my plans, he volunteered to help. I knew fellow writer Steve Reynolds (wannaskawriter) would want to join in too. I knew then that I'd have to provide breakfast. I encouraged Joe and Steve to bring their own coffee.

   On Tuesday morning, August 12, 2025 at 5:45 a.m., I drove to Wayne's World, a patch of woods we own just north of the rumble strips. We call the woods Wayne's World because we bought the land from a guy named Wayne at a time when the Saturday Night Live skit Wayne's World was popular. The name stuck.

   So I drove into the heart of the woods through waist high wet grass along the road Wayne had built back when he planned to put a trailer house there.  But he moved someplace else and sold the land to us. It was still dark when I dropped off the breakfast fixings, chairs, etc. and backed out of the woods. By that time my colleagues had arrived and after I cooked myself some coffee, we returned to the sampling site in Steve's car. We parked  Steve's car out of sight and set up our chairs. The temperature was 62° with a SW wind of 3 mph. Perfect.

   The first vehicle passed at 6:14. A non-rumbler. It was eight minutes before another vehicle passed; also a non-rumbler. At 6:29 & 30, two rumblers passed. I was now thankful I had a crew to back up my observations. We were only 100 meters from the rumble strips, but heavy foliage can play tricks with sound. There were several more vehicles before 6:46, including two semis hauling gravel for the construction project on 89, a few miles to the south. Both trucks hit the rumble strips.

   There was now a no-vehicle gap of 25 minutes. The rush of workers to the snowmobile factory in Roseau was over. That 6:46 guy would have to drive 85 mph and would still be three minutes late. There's always a someone like that. This gap gave me a chance to cook breakfast on my little wood burning stove. The blaze from the stove was cheering in the cool morning air.

   I was chagrined that I had left my toasting rack at home so we had to eat our fried eggs on buttered bread,  but no one complained. I hadn't cooked breakfast outside in many years so this was one of the benefits of working in the field.

   Traffic started again at 7:13. We were now observing the employees at businesses in Roseau that opened at 8:00 a.m. The last vehicle passed at 7:42. We left the site at 8:00 after making sure our fire was dead out.

Results: 

Total number of vehicles: 16

Drove over rumble strips: 11

Avoided rumble strips: 5

Conclusions: In this survey 68.7% of vehicles ran over the rumble strips while 31.3% did not.

Recommendation: The Department of Transportation should survey drivers possibly on their driver's license renewal form as to the reasons they do or do not run over rumble strips. 

Thank you for your interest.

Survey team: Joe McDonnell (author), Joe Stenzel, Steve Reynolds