A before-and-after study of driver stopping propensity at red light camera intersections

This paper reports a before-and-after study which evaluated the impacts of installing and operating red light cameras at two "T" and one "X" signalized intersections on driver stopping propensity upon the onset of amber. Rather than using video cameras, a special purpose data logger working in conjunction with loop sensors was used to gather traffic parameters, vehicle stopping/crossing movements, and signal phases. Logistic modeling was employed to model the revealed stopping/crossing decisions of non-platoon vehicle drivers in response to the onset of amber with traffic, situational and behavioral variables, including their interactions. The results indicate that the variable Cam_Inst that gathered the impacts of red light camera (RLC) installation on driver decision-making at signalized intersection was significant at 5% level only for the camera approach model of the cross-intersection. The significance of Cam_Inst was undermined for the camera approaches at the T-intersections by the inclusion of a significant two-order variable defining the interaction of Cam_Inst with distance from the stop-line. One may, thus, infer that RLC has a fixed-quantum effect at the cross-intersection, but an accentuated effect with distance at the two T-intersections. Lastly, the effects of a RLC at an intersection on the stopping decision at the non-camera approaches were minimal.