There are two ways to change behavior. The most effective way to change behavior is using them both and at the same time. The two ways are: rewarding wanted (good) behavior and punishing the old, bad behavior. The rewarding and punishing activities should be explained to the people involved, and the results of the level of change should be communicated and discussed in public. In this way, people are kept informed about the results on a higher level than just their own behavior. They slowly get the feeling that THEIR behavioral change is part of the total change in society. This is also the start of a psychological process: very few people want to belong to the minority that does not change its behavior when everybody agrees that the change contributes to solve the problem, in this case the traffic jams.