Larger turning vehicles exhibit offtracking characteristics. Offtracking is a function of a larger vehicle’s spacing between tyre axles. The maximum distance between a larger vehicle’s front (lead) axle and its rear (trailer) axle determines offtracking. It is measured from the centre of the rear trailer axle with respect to the centre of the lead axle. Offtracking can occur in low-speed operating environments (intersections), or in higher-speed operating environments (highway horizontal curves).  

These characteristics must be considered in the design of new or upgraded roadways, and checked with swept path analysis. When it’s incorrect we can see roadside furniture damaged, or worse pedestrians or cyclists caught up in the offtracking.