The INDOT – Purdue University APT facility is located at the INDOT Research Division in West Lafayette, IN. The APT is housed in an approximately 2,000 square feet (185 square meter) environmentally controlled building. The APT facility is composed of a testing pit area of 20 foot (6.1 m) wide by 20 foot (6.1 m) long by 6 foot (1.8 m) deep, a loading mechanism and control and monitoring equipment. The APT carriage (picture on the left) can be equipped with either a full-size, dual-tire truck wheel or a super-single, half-axle assembly. The tire can be inflated at various pressures. This setup allows speeds up to 5 mph (8 kph). The APT loading mechanism uses a system of four air pistons that maintain a constant force up to 20,000 lbs (89 kN). This load can be programmed either in static or dynamic modes. These cylinders also allow the wheels to be raised and returned to the start-up position of the test pad if used in one direction type of testing.

The APT facility is used in projects of different kind (i.e. asphalt, concrete). The picture on the right shows a concrete pavement instrumented with dowel bars, strain gages and thermocouples that will be loaded. Temperature and deformations of the pavement will be measured to calculate stress distributions and damage. This research is currently being executed and studies the conditions of the pavement at the moment that it is opened to construction traffic loads.