Requirements for the colour of rear turn signals differ between the standards set by the Economic Commission for Europe (ECE) and United States standards. In the ECE standards, all rear turn signals are required to be amber, while in the United States, they can be either red or amber. This difference has led to questions about whether there are safety differences associated with turn signal colour. Consistent colour coding of functions might facilitate recognition of the meaning of a signal, allowing a driver to respond more efficiently. It is also possible that, apart from colour coding, an amber turn signal is more conspicuous to a following driver amid a field of red tail and stop lamps. This might allow an amber turn signal to be recognized more quickly or confused less often with another rear signal. Figure 1 illustrates one way in which such confusions might lead to rear-end collisions. The possible effects of turn signal colour have been explored in a limited number of previous laboratory studies and crash analyses, with mixed results. Some laboratory studies suggest no effect on driver responses, while others cite advantages with amber lamps. Crash data analyses are similarly mixed. The following analysis revisits this issue with the benefit of a larger pool of crash data than before, and a logistic regression model that includes many factors–such as driver age, gender, vehicle model, and vehicle age–that were not considered in previous analyses. This Vehicle Safety Research Note is a summary of the technical research report: The Influence of Rear Turn Signal Characteristics on Crash Risk (DOT HS 811 037). This report can be downloaded free of cost on the Vehicle Safety Research section of NHTSA’s Web site (http://www.nhtsa.gov).(Author/publisher)
Samenvatting