Letter sizes are chosen according to the standards for the elderly and the text has contrasting colours. Where the elderly and disabled are being specifically considered, written instructions can also be supplemented with audio instructions. One way of doing this is to locate the terminal near information kiosks where personnel can be available to assist. Terminals placed outdoors are usually protected against vandalism. Screens or terminals are usually made vandal-resistant, and it is also possible to provide alarms for terminals.
Some terminals have vibration alarms, so that they switch themselves off if they are kicked.
Some systems are stand-alone. Service-disturbance information shown on the PIT system in Genoa is based on the AVM DGPS system. Experience Implementation of a system is an iterative process in which a version is installed, tested, user surveys are made and after that the system is modified to create a better version. The time and money spent in the implementation can be much greater than expected. In Valencia recovering from failures caused by improper use has been difficult.