EXPERIENCE WITH TRAFFIC CONFLICTS IN CANADA WITH EMPHASIS ON "POST ENCROACHMENT TIME" TECHNIQUES .INTERNATIONAL CALIBRATION STUDY OF TRAFFIC CONFLICTS. PROCEEDINGS OF THE NATO ADVANCED RESEARCH WORKSHOP

Following an initial investigation of the g m (brakelight) conflict recording technique in various Canadian cities in 1972/73, a study was undertaken to define conflicts in such a way that a better link between these and accidents could be established. The conflict definition arising from this work was referred to as "post-encroachment time" (pet). In the new technique, six conflict types are recorded by teams of three or four observers, each of them being attributed a specific task; pet is timed for every event noted. Evaluation of the pet technique was carried out from 1978 to 1981, but due to small data sample sizes (especially in terms of recorded accident frequency), results were inconclusive. One major positive finding, however, is that pet conflicts are generally better predictors of expected accidents than either past collision history or volume exposure factors.(a) for the covering abstract of the conference see IRRD 279243.