Someone bought a new car and asked the Belzer Rebbe Reb Ahare'le for a Segula to ensure he will not get into any accidents on the road. The Rebbe offered him two tips. First said the Rebbe make sure you obey all the traffic laws and treat them as you would the Aseres HaDibros. Secondly, said the Rebbe, when you see people walking give them a ride and in the merit of the Chesed you will be protected from any harm. (Shevet HaKehosi 5:241:7).
[From revach.net]