The Iowa Department of Transportation is using a mix of new and old technology to count traffic in a busy area along Interstate 80-35 in Des Moines. D.O.T. spokesperson Karen Carroll says the high-tech laser system counts the vehicles.

Carroll says the system puts two lasers across the road and counts traffic as the vehicles cross the lasers. She says they decided on this system because it would be costly to have to shut down and tear up the road to install the traditional loops under the roadway that measure traffic. Caroll says its’ called the “AxleLight” laser system and is able to tell the type of vehicle by the number of wheels and the distance between each wheel.

via Radio Iowa: DOT uses lasers, turbine to count traffic.