Comments on Effects of Vehicle Type and Age on Driver Behaviour at Signalized Intersections

Abstract

A recent paper in the literature reported that driving patterns at a signalized intersection were correlated with the type (e.g. small, standard-sized) of vehicle being driven. This report stimulated the authors to re-examine data previously collected on driver response to the amber light at two signalized intersections, one with a 48 km h^-1* speed limit and the other with a 80 km h^-1 speed limit. Our analyses provided no evidence that when actually confronted with an amber light, drivers of different vehicle type produced different driving patterns. However, there were effects which can be associated with vehicle ago at the 8O km h^-1 intersection, the drivers of newer vehicles being more likely to drive into the intersection after the light and turned red. Drivers of ‘ standard-sized ’ vehicles had higher approach speeds and deceleration levels than drivers of ' non-standard-sized ' vehicles. Also, drivers of newer vehicles used higher deceleration levels than drivers of older vehicles. These findings are used to offer a possible explanation of the result relating driving patterns to vehicle type previously reported in the literature. The data are also used to illustrate the practical existence of theoretically predicted ‘ dilemma zones ’.