Why Are There Rectangles On Iowa Highways?
No matter where you are in the country, signage is pretty universal. The octagon is reserved for stop signs, rectangles are for regulatory or warning signs, and a pentagon marks off a school crossing zone.
Even “signs” painted on the roads are pretty universal. On highways, they can help guide drivers at exits, indicate when it's safe to pass, guide you through splits in the road, and remind drivers what road they are on. But when you drive on the highway in Iowa, there are unique road markings that you don’t really see anywhere else.
I drive Interstate 380 a lot and something that stands out to me on the drive is the rectangles painted in the left, passing lane. As an Iowa transplant, these rectangles are not something I have really seen elsewhere.
At first, I thought these rectangles were to help drivers drive straight in their lanes. I always try to make sure I center my car with them. But after talking with a coworker, a quick Google search, and reaching out to Iowa State Patrol, I have learned this is not the case.
According to Sergeant Alex Dinka with Iowa State Patrol, the white rectangles on the highway are aircraft zones.
We use these while the plane is flying in the air to check vehicle speeds on Iowa Highways. They do this by checking time and distance.
Iowa is one of the first states to use aircraft to help search for traffic violations. The Iowa State Patrol’s Air Wing program began in 1956 with two aircraft and two pilots based in Des Moines. Today, there are eight pilots serving the patrol with seven aircraft based at six airports throughout the state.
In 2021, the Air Wing program generated 2,234 traffic enforcement contacts.
Welcome To Iowa - City Signs #1
Welcome To Iowa - City Signs #2