Apparatus for measuring the articulation angle between a tractor and trailer connected by a kingpin and fifth wheel include a transfer assembly associated with the kingpin and interacting with the fifth wheel such that the transfer assembly is rotationally moved relative to the kingpin by relative rotational movement between the kingpin and the fifth wheel. This rotational movement is read by an articulation sensing mechanism having one of a reader element and output element mounted to the transfer assembly and the other of the reader element and the output element operatively mounted to the trailer such that the reader element and the output element interact to provide a signal corresponding to the articulation angle between the tractor and trailer. This signal can be analyzed by a processor for any beneficial use, for example, outputting to a counter steering mechanism.