The Wheel Trackers CRT-WTEN1 and CRT-WTEN2 are supplied with a UKAS certificate providing conformance to EN 13108. Wheel tracking is used to assess the resistance to rutting of asphaltic materials under conditions which simulate the effect of traffic. Test specimens can be either slabs prepared with a laboratory compactor or 200mm Ø cores cut from the highway. The Wheel Tracker CRT-WTEN1 performs both procedures A and B specified for the small scale device in EN 12697-22. Procedure A requires that six specimens are tested. For procedure B, only two specimens need to be tested, but rut depth must be measured at more points along the longitudinal rut profile. To speed up the testing process, the Wheel Tracker CRT-WTEN2 was designed to test two specimens simultaneously.