Reducing Risk Taking at Passive Railroad Crossings With Active Warnings
Thomas J Smith
Report no. Mn/DOT 2004-33
This simulated driving study evaluates driver interaction with a low cost active warning system being considered by Mn/DOT for potential installation at passive highway-rail intersections (HRIs). The objective of the study is to ascertain if, relative to HRIs with passive signage, drivers interact in a more cautious manner with HRIs equipped with active warning system technology. The experimental design comprised: (1) 0.65 mi simulated roadway, with simulated HRI 0.644 km (0.4 mi) from start line; (2) 1 trial (start to end line) lasts about 1 min; (3) 120 trials/subject; (4) simulated train encountered in 13.3% of trials; (5) 25 subjects (Ss) (15 females, 10 males); (6) independent measures are: 4 control/test conditions; train absent/present; visibility clear/fog; (7) 2 control conditions: Control #1-advance passive warning sign (WS)/ crossing (Xing) passive WS; Control #2-advance passive WS/Xing active WS (flashing red lights); (8) 2 Test Conditions: Test #1-advance active WS (flashing yellow lights)/Xing active WS; Test #2-advance active flashing variable message sign (VMS)/Xing active WS; and (9) dependent measures are visually observed unsafe incidents and objective simulated driving measures (speed, braking, acceleration), plus responses to a post-test questionnaire (PTQ). Major results are: (1) statistically significant main effects of train (present/absent), visibility (clear/foggy), and Xing WS conditions; (2) incidents of vehicle beating train or hitting train are higher for trials with a passive advance WS, relative to those with an active advance WS; (3) with a train present and clear visibility, for all measurement intervals, active advance WS are associated with lower mean vehicle speeds, compared to mean speeds observed with passive advance WS; (4) active advance and Xing WS are perceived by PTQ respondents to be more usable and more conspicuous than passive advance and Xing WS ; and (5) flashing words (e.g., a VMS) are perceived by PTQ respondents to be more conspicuous than flashing lights on an active advance HRI WS.