Accurate Travel Times Using Portable Tape Recordings.

This paper describes the development of a method for accurately recording the number plates and times of passing of a high sample of vehicles in heavy flow situations using low cost portable tape recorders. The method has been extensively tested and found to -be better than existing methods in terms of timing accuracy, the sample size obtained, and ease of transcription. A similar method has been developed for recording data from moving observer surveys, enabling the job to be carried out by only one observer with consequent savings in survey costs.