Driver response at a signalized T-intersection during an amber blackout.

This paper reports a comparative study which evaluated the difference in driver response along an approach of a signalized T-intersection with and without an amber blackout. About 20 h of traffic data were recorded during the amber blackout where drivers approaching a signalized intersection after the termination of the green signal light encountered no amber light indication for the entire amber period before the onset of the all-red display. An identical timeframe of traffic data the following day during regular amber light operation were available to assess driver response during this critical signal phase-change period. The findings indicated that drivers would decelerate initially to slow down their vehicles and then took advantage of the amber blackout by violating the red as far as traffic flow conditions permitted such risk taking action. The increase in red-running violations could be attributed to drivers, who could have crossed during amber, slowing down their vehicles that subsequently crossed during red. Also, drivers located further upstream as well as those who could have stopped but chose to violate the red signal contributed to such an increase. (Author/publisher).