In bus and train transport there are a number of requirements for the safety of the entrance door. For example there are requirements to provide obstruction detection within the door system. This should reverse the movement of the door should a passenger or some other obstruction restrict the doors operation. In case the door movement is realized by a pneumatic cylinder, obstruction detection can be achieved either by using a sensitive edge or by sensing of the door actuator pressure. Detection valve providing an electrical or pneumatic output signal to the door control system to initiate door opening. The pinching time of the subject or person must not exceed 1 s. This article describes the main safety requirements for door systems of intercity traffic trains and, above all, experimental verification of obstruction detection valve behaviour.