Abstract
A signalized intersection must -of course- in the first place be safe.Additionally the following requirements have to be met: -The traffic- control must be simple; i.e. there are no more exclusive phases than strictly necessary. -The traffic- control must be credible; i.e. the road-user understands why he is waiting for the red traffic-light. -The inconvenience for the traffic (delay, stops) and the surroundings (noise) must be minimized according to pre-determined aims.