Frankly, make them terrified! If two wheels are an issue, ride a trike. But people jump in a "safe" metal box with all the driver assists, crash cages and sound insulation from the outside world, and forget - or never knew in the first place - how dangerous the roads actually are. Scare people. Make them wary. And perhaps make them think a bit more about what they are doing when they are being impatient on the road and exercising poor speed judgement.