The reasons for the traffic jams in Bangkok can be divided in two categories: behavioral reasons and traffic flow reasons. Next to that, there are some improvements possible in the general transportation policy in Thailand. The problem of traffic jams in Bangkok is a complicated one, and anybody that thinks he/she can solve the problem in a few years is – in my opinion – telling lies. The problem needs an integrated package of solutions in which the change of behavior of the Bangkokian car-owners and drivers of buses, vans, tuk-tuks, songtaews and motorcycles should be the central focus; and that for many years to come. Changing behavior is difficult because the normal reaction of people is resistance to change. “Why should I change my behavior (and not the other ones)?” “What did I do wrong so far then?” “I only drive my car 45 minutes to my office and 45 minutes back. That cannot be the reason for a traffic jam”. “I do not have an alternative way of transportation than talking the car.”