" After he gets a driver's license, should your son correct other drivers who are speeding by getting in front of them and setting cruise control at the speed limit? "

Yes.

In fact, it's best to get a friend to drive along with you so that your friend can be in the other land controlling traffic at the speed limit.

Remember, as Leo XIII said, "error has no rights".

Are we not our brother's keeper?

Are we not all responsible for the ideal functioning of the world?

Do we not have to hold our fellow man to account?