Information and communication technologies may be widely used on the roads in future in so-called 'Intelligent Transport Systems' (ITS). Systems that warn of upcoming hazards or intervene to avoid them could prevent accidents. ITS could also enable road charging and the better provision of information to drivers, which may help to reduce congestion. This POSTnote outlines current and future applications of ITS in road transport, as well as technical, behavioural and economic limitations to their deployment.