Sticker shock: simple bus ads could drastically improve road safety in Kenya

Road safety is a serious public health issue worldwide: 1.3 million people are killed in road transportation accidents every year, most of which occur in the developing world. In a study published in PNAS, researchers present the results of a randomized intervention to test whether a simple sticker could be enough to change people’s behavior behind the wheel. This extremely simple and cost-effective approach reduced insurance claims by 25 to 33 percent.

The road safety experiment was conducted in Kenya between 2011 and 2013. Stickers with evocative messages were posted inside the country’s 14-seater minibuses, suggesting that passengers speak up if their driver was being unsafe. Vehicles (and their drivers) were recruited into the study at the point of insurance purchase then randomized into one of the treatment groups or one of the control groups.

The experiment included several different treatment groups, including a placebo set that saw a neutral sticker saying "Travel Well." The other three groups all saw stickers intended to catch eyes:  the first used evocative messages with text about dangerous driving and no images; the second saw evocative messages with text about dangerous driving and images of people speaking up; and the third viewed evocative messages about dangerous driving with images of post-accident riders. Within each of these groups, there were subgroups in which the message encouraged either individual action or collective action—the latter involved a message roughly equivalent to “together we can.”