Abstract
The author traces the development of technology involved in barrier control and ticket dispensing. In the US the focus has been on an 'intelligent' barrier which communicates with a central computer, transmits information to the driver and operator and accumulates statistical data. In Europe more attention has been paid to control through ticket dispensing devices. A trend is seen towards the merging of technologies and examples are described of PC-operated systems in North America. The use of MS-DOS allows upgrades and the application of programmes for different situations. US practices, currently more labour-intensive, are expected to become more efficient with the use of European machine readable systems.