Investigation has shown that many drivers are inefficient in their choice of route. On average at least 4 per cent of all route kilometres are unnecessary and about three-quarters of the wasted kilometres may be recoverable in principle. This would be worth about £470m per year (net of fuel tax) at 1975 prices. The wastage might be reduced by improvements to maps, improvements to signs, or provision of automatic route guidance. The way in which the wastage arises suggests that improvements to maps and signs would only produce a marginal (though worthwhile) saving. The most promising method is the application of automatic route guidance. A cost benefit analysis shows that, after an introductory phase lasting about 10 years, the annual return from the system might be at least £270m (net) at 1975 prices. A discounted cash flow treatment of the analysis shows that the net present value (at the time when the decision is taken to install the equipment) could be in the region of £600m if the first 20 years are considered. Recommendations are made for research to confirm these conclusions and to investigate the necessary techniques. (Author/publisher)
Abstract