The UK Highways Agency has been investigating the possible use of Traffic Control Centres (TTCs) at a higher level of management, which should be able to generate cash flow. TTCs are expected to be able to do this by selling traveller information through the traffic information highway (TIH). There are also plans for generating secondary revenue by leasing or renting telecommunication links buried alongside all motorways and some trunk roads. Such land could be used for erecting communication towers, for example for cell phone nodes. Through its partnerships, Teleste has provided a large network of closed circuit television (CCTV) systems using the fibre content of these links; so far, they have all been analogue systems, but the link capacity is about to be improved by digitising them. At present, analogue solutions can multiplex up to 64 real-time video signals with 128 audio-data signals onto one single-mode fibre, over a transmission link of tens of km. With standard MPEG compression, it is possible to obtain a similar standard of near real-time images and multiplex many more images onto the same fibre. There is capacity for 30% more payload, and distances of 80km between repeaters. However, the transition to digital needs care, as it would be disastrous to move from an adequate analogue system only to go digital.
Samenvatting