More than 4,500 pavement sensors measure the effects of traffic and the environment on the three-mile test section on Interstate 94 and the 2.5 mile closed loop section. The sensors are placed at various levels in the roadway, from the surface into the subgrade.

Sensors embedded in the asphalt and concrete surfaces of the roadway measure the amount of movement or strain induced in the structure due to truck loadings or environment conditions. Sensors embedded in the gravel and soil layers under the pavement monitor pressures from truck loads and environment conditions such as temperature, moisture content, and frost depth.

Information from the sensors is collected and sent to computers at the site and at the Mn/DOT's Materials Research and Engineering Laboratory in Maplewood. Every day, millions of bytes of data are sent to the lab. The data is also shared with the University of Minnesota and other interested researchers around the world.

The test site also includes an automated weather station and a weigh-in-motion (WIM) scale. The weather station provides information such as temperature, barometric pressure and wind speed and direction. The WIM scale determines vehicle type, speed, weight and axle spacings.

Sensors and other instruments give researchers a constant picture of the road conditions that enables them to measure and understand the forces acting upon the roadway.