I hate to say it, because I would hate to have to do it because others suck at driving...But require people every five years to go back through an 4 hour course where they remind people on driving distances, who has the right of way when merging on/off the highway, how far to stay behind someone at a stoplight.
Either that, or spend the money on public service TV spots that run all the time that tell people not to pull out on a rural road when the speed limit is 55 mph or to always use a turn light for 10 seconds during a lane change. They might not "FIX" the problem, but might help over time by re-enforcing better habits.