Information that is conveyed only visually, such as stop notices or the route number of a bus, is not practically accessible to blind people which prevents trouble-free public transport operations. In accordance with the “principle of two-senses", all important information should therefore be additionally offered audibly (acoustically) or tactilely (tactile signals).
Barrier-free stops usually have a tactile guidance system. From Braille on signs and staircase railings, to tactile strips embedded in the floor, visually impaired people should be guided safely to and from the platform.
Some stops are equipped with acoustic announcements for the current departure times. The corresponding button is located under the display case in the waiting hall, or on a separate mast.
In the underground stations, the incoming train is announced with line number and destination, whilst every vehicle announces the next stop and also the exit side.
Wherever possible, elements such as doors, bus stops or treads are highlighted in contrasting colours and provided with tactile surfaces.