The check is the last part of the riding feedback loop. Just as scan and plan together form a tight loop, so there can be a tight execute-check loop. If an execute doesn't check out, there may be no time to rescan or replan. If a turn suddenly becomes a skid, there is no time to analyze - it is straight back to execute again. It is your instinctive reaction. If there is any analyzing involved, it was done beforehand. The execute-check-execute loop normally applies in emergency responding, but it can have other uses.


This is a way of testing the water. Suppose you come to an intersection at the same time as another person, and it is not clear who is to go first, and you both have stopped. Test the water by giving a little lurch forward, then drop the acceleration. If the other vehicle stays put, they will let you go. If they also go forward, you let them go.

The slow move

If you are changing lanes and cannot direct sight, a slow lane change is an option. For example sometimes it is raining so hard that stability is paramount, and turning your head is too dangerous. In a slow move you check your mirrors and move into the other lane about two or three times as slowly as you normally would. This gives any other driver time to avoid you.

Short lane change

Instead of moving from the center of one lane to the center of another, move from the “outside” of your start lane to the “inside” of the target lane. This “short” lane change is better than the full lane change. Even if you conflict with a car in the target lane, there is a good chance it will miss you.

So for example if you cross two lanes, it will involve three distinct steps: first short lane change, move to other side of lane, then second lane change.