In a paper in 1988 it was confidently predicted that there would be a commercial dynamic route guidance system operating in London by about 1992. When in 1993 a review was conducted of why the optimism of the late 1980s had not been played out in reality, there were four main reasons given for the delays:
(i) Availability of mapping data.
(ii) Establishment of good traffic monitoring networks.
(iii) Choice of communication method.
(iv) Need for integration with other Intelligent Transport Systems (ITS) services.
