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.”
The effectiveness of the campaign was measured by the number of insurance claims filed during the treatment period. Additionally, short interviews with almost ten thousand passengers were completed post-mini-bus ride. Finally, field researchers completed over four thousand mini-bus rides during which they measured the trip speed, manually recorded the behavior of drivers and any accidents, and tracked the behavior of passengers.
The researchers found that the stickers reduced the insurance claims of minibuses affixed with stickers between 25 and 33 percent.
The success of public health interventions is usually reported in a quantity known as disability-adjusted life years (DALYs), a measure of years of quality life lost due to illness, disability, or death. The insurance claim data data from this intervention allowed the researchers to estimate that the cost-effectiveness of the intervention was between $13 and $60 per DALY saved. The cost effectiveness of the more impactful stickers, which reduced accidents by as much as 34 percent, was between $10 and $45 per year of quality life saved (DALY).
The results show that text-only messages were the least effective. This may be because of limited literacy in the passenger population, but it could be due to the increased emotional/psychological response to images. The collective-action messages were more effective than the individual-action messages, perhaps because passengers felt more empowered by the sense that they were part of a group.
In addition to the sticker campaign, a radio campaign was aired on two local radio stations. However, there was no significant impact on the number of insurance claims that were made during the period when these radio interventions were aired.
Overall, the results of this study suggest that improving road safety in developing countries could be as simple as investing in a sticker that would inspire passengers to complain about unsafe driving. Given the low-cost, high-impact nature seen in this test, implementation of a similar intervention in other developing countries with high road-accident rates could have far-reaching consequences.