VARIOUS VOLUME DEFINITIONS WITH CONFLICTS AT UNSIGNALIZED INTERSECTIONS

This paper presents data for 15 four-leg unsignalized intersections. The data concerning traffic volume and conflicts of four levels of severity grades were collected by the use of a video camera. The main objective of this paper is to examine the correlation between various volume definitions and conflicts. By adopting the approach volume rather than the total entry volume, it was found that there is always a basic volume that influences the occurrence of certain types of conflicts. This basic volume is made obvious when considering its effects on the serious severity grades G3 and G4 of the influenced conflict type. It was further concluded that the incorporation of other volume combinations, as an exposure measure, may provide misleading correlation between volume and conflicts, due to incorporating irrelevant traffic volume into the correlation.