A study of Singapore taxis has revealed the color of the car makes a difference to its accident risk. Over a period of 36 months, yellow taxis had 6.1 fewer collisions per 1,000 vehicles than blue ones. That's 9 percent fewer accidents. As the authors of the study note: “This finding can play a significant role when choosing colors for public transportation and may save lives as well as millions of dollars.” The study is published in the Proceedings of the National Academy of Sciences.
Past studies have found that certain colors of cars are less likely to be involved in accidents than others. However, most such research has a major flaw – it can't distinguish between intrinsic safety and self-fulfilling prophecy. After all, if people think white cars are safer than red ones, safety-conscious drivers will probably buy white cars and have fewer crashes than speed devils who prefer red. Some studies have an even bigger problem in that they lack precise distributions of color frequency to use as a base.
Professor Teck-Hua Ho of the National University of Singapore saw an opportunity to do better. The largest operator of taxis in Singapore uses yellow and blue cabs since two competing companies merged. Hiring is done by the same team, with drivers allocated randomly. The drivers who operate both color vehicles have fewer accidents when in yellow cabs.
From 2012 to 2014, yellow taxis were involved in 65.6 accidents per 1,000 taxis per month, while blue cars had 71.7 accidents per thousand. Ho and his co-authors were able to rule out differences in the time cars were on the road and their average speeds.
Deeper examination of the data revealed the difference lay in accidents where the other driver failed to notice the taxi, such as when the taxi was hit from behind. The difference was larger at night.
Although Ho's work shows that you're better off catching a yellow taxi than a blue one, and you might want to think about the color for your next car, there could be a paradox if everyone takes the same advice. The paper notes that yellow taxis have been popular since 1907, when a University of Chicago study found they were the most likely to stand out among the black Model-T Fords that dominated the roads at the time, making them easier for potential customers to spot.
If enough people start buying yellow cars for safety reasons, blue vehicles may become so rare they are more noticeable by comparison, and therefore end up being safer. Still, we're a long way from that point, so if you want to minimize the chances of a crash, take the big yellow taxi.