Driving Safely
Seeing ahead, managing space and speed, and stopping distance.
2.1 Seeing ahead and around you
Good drivers look far enough ahead to react in time. Most experienced drivers look 12 to 15 seconds ahead — at highway speed that is about a quarter of a mile.
- Check mirrors regularly, and more often in traffic, at intersections and when changing lanes.
- Remember the blind spots alongside and behind a large vehicle.
- Signal early, and communicate your presence with lights and horn when needed.
Check How far ahead should you look while driving?
2.2 Managing space (following distance)
A common rule from the model CDL manual:
- Below 40 mph: leave at least one second for every 10 feet of vehicle length.
- Above 40 mph: add one more second.
Also keep space overhead (low clearances), below (railroad humps, soft shoulders) and to the sides, especially in high wind.
2.3 Speed and stopping distance
Total stopping distance = perception distance + reaction distance + braking distance.
- On a wet road, reduce speed by about one-third.
- On packed snow, reduce speed by one-half or more.
- On ice, reduce speed to a crawl and stop driving as soon as you can safely do so.
Check How should you adjust speed on a wet road?
2.4 Distracted driving
Federal rules prohibit CMV drivers from texting while driving and from using a hand-held mobile phone while driving. Hands-free use is allowed only if it requires no more than a single touch to start or end a call and you do not have to reach for the phone.