ABSTRACT
The Wheel Tracking Rate (WTR) test was developed by TRRL in 1977 to simulate the in-service rutting of hot rolled asphalt. The test has been published as a British Standard Draft for Development DD184.(1)
Briefly, the test involved subjecting a 50mm thick slab of material, either manufactured in the laboratory, or using a 200 mm diameter core taken from the wearing course after laying, to a rolling wheel load, which traverses the specimen at a constant temperature, normally 45°C, and standard load. The test measures rutting under the wheel over a period of time.
