Can You Improve the Safety of your Fleet by Buying Silver Painted Cars?

Silver colored cars are surprisingly less likely to be involved in an accident than cars of other colors, says a report, published in British Medical Journal, by researchers in New Zealand. Silver colored cars were involved in 50% fewer accidents than would be expected by the proportion of silver cars on the road. They found that brown, black and green cars had a slightly higher accident rate, while white, yellow, gray, red or blue were all about the same with average accident records.

http://bmj.bmjjournals.com/cgi/content/full/327/7429/1455

The investigators tried to identify confounding factors that could be responsible for the unexpected results but found none. There was no correlation between people who drive silver cars and age of driver, sex, educational level, ethnicity, alcohol or drug use, vehicle speed, average time spent driving each week, vehicle speed, vehicle age, vehicle value, engine size, insurance or driving license status, road type, ambient light conditions (day, night, twilight), and a few other risk factors that could possibly explain the results. 

The conclusions were based on crash statistics over a twelve month period and covered 572 accidents, not a small sample. The study authors make no claim that the results represent the situation in any part of the world apart from New Zealand and do not claim they know the reasons for the findings.

Personally, I would have guessed that the colors that are the most visible at night, white or lime yellow, could have a small effect in reducing accidents, but white cars were not safer than the other colors. Brown and black are more difficult to see at night and green can get lost in the background during the day, so the slightly below performance of cars with these colors is plausible.

I believe that in the overall population, if silver truly made such a big difference in accident results, the actuaries at insurance companies would have noticed by now. Last time I was in the market for car insurance, none of the agents asked about the color of our cars. So I believe the findings must have been a statistical fluke.

I wish the researchers had gathered some statistics at body shops. Crashed cars usually are repaired and repainted, so such statistics could have confirmed or contradicted their findings. Now there's an idea for some graduate student in need of an idea for a major paper.