One of the most common problems in the process of traffic management is the determination of the proper traffic volume. On the one hand there is a tendency of increasing traffic volume – it brings profits to all subjects involved in the transportation process. On the other hand there is a tendency to decrease traffic volume – it assures better safety. It is necessary to solve the problem of finding a compromise between those tendencies. Solving this problem is possible, based on developed methods of safety dimensioning that use the concept of traffic smoothness for quantitative evaluation of traffic safety level. In the paper the concept of those methods is explained. Besides, presented are results of simulation research on the relation between traffic smoothness and the safety level in a restricted control sector. Although the paper presents the implementation (examples) of the problem in the air traffic management, similar procedures and methods may be applied to the marine traffic
