Here's some advice from the South Carolina DMV on how to safely share the roadway with cyclists. You may want to pass this list along to your drivers as a friendly reminder.
1. When you’re attempting to pass a bicyclist, treat the bicycle as any other vehicle you would pass.
2. Allow for the bicyclist to make mistakes. Watch for swerving cycles and sudden turns.
3. The horn should be used to attract the bike rider’s attention and not as a threat to get out of your way.
4. Be extra careful when driving close to cyclists and maintain a safe operating distance between the motor vehicle and the cyclist.
5. Before passing a cyclist in a narrow traffic lane, wait until the traffic is clear in the opposite lane and then change lanes to pass the cyclist. Do not attempt to squeeze past the cyclist.
6. Leave ample room when turning right after passing a cyclist so the cyclist is not cut off when you slow for the turn.
7. Even with a proper headlight and rear reflector, a bike is still difficult to see. Use extra caution after dark, especially in poorly lighted areas.
8. Remember to anticipate cyclists at parks, playgrounds, near schools and especially in residential areas. Night is a very difficult time for the bicycle rider and the automobile driver; alertness is required from both.
9. After parking on streets and before getting out of a motor vehicle, you and your passengers should be careful not to strike a bicyclist when opening car doors.