Here is some driving advice on the art of passing, taken from the Colorado Driver Handbook. You may want to pass (no pun intended) this along to your drivers as a friendly reminder. 

Whenever signs or road markings permit you to pass, you will have to judge whether you have enough room to pass safely. If you do, follow the five steps for changing lanes. 

They are:

1. Turn your signal on.

2. Check your mirrors.

3. Check your blind spot. (Look over your shoulder.)

4. If it is safe, you may change lanes.

5. Turn off your signal after completing the lane change. 

Return to the driving lane when you can see both headlights of the other vehicle in your inside rear-view mirror, using the five steps for changing lanes again. Do not count on having enough time to pass several cars at once. To be safe, as a general rule, only pass one vehicle at a time. 

You may pass another vehicle on the right side on a one-way street or on a roadway with two or more lanes of traffic in each direction. At no time shall such pass be made by driving off the pavement of the main-traveled portion of the roadway. 

Do not pass:

• If you cannot safely return to the right-hand side before coming within 200 feet of an oncoming vehicle, including a bicyclist in the oncoming lane or shoulder.

• If you cannot safely return to the right-hand side before the solid yellow line begins. If passing a bicyclist you can briefly cross a solid yellow when there is no oncoming traffic and you have a clear view ahead.

• On a curve or hill when your view is obstructed.

• Within 100 feet of a marked or unmarked intersection, or railroad crossing.

• Within 100 feet of any bridge, viaduct or tunnel when view is obstructed.

• A bicyclist unless you can allow a minimum three-foot buffer zone between your vehicle, including mirrors and the bicyclist.