Heckle and Chide: Results of a randomized road safety intervention in Kenya

We report the results of a randomized field experiment aimed at improving the safety of long-distance mini-busses or matatus in Kenya. Our intervention combines evocative messages aimed at motivating passengers to speak up against bad driving with a lottery that rewards matatu drivers for keeping the stickers in place. Independent insurance claims data were collected for more than 2000 long-distance matatus before and after the intervention. Our results indicate that insurance claims fell by a half to two-thirds, from a baseline annual rate of about 10%, and that claims involving injury or death fell by 60%. While we are unable to identify the mechanism(s) underlying this effect, the intervention is more cost effective in reducing mortality than other documented public health interventions.