Studies of drivers route choice criteria suggest that most are seeking the shortest or quickest route to their destination, yet less than 50% achieve their stated objective, whilst a comparison of the routes they follow against the existing direction signs suggest that 86% have followed the direction signs. A suite of computer programs - signpost - has been developed to study and improve the accuracy of information on direction signs. A set of "practical" signs were produced by the programs and compared with the corresponding existing signs. The comparison implied a need, on average, for 1 directional change every 20 intersections and 7 place name, distance or route number changes per intersection, the latter being due largely to inconsistencies on the existing signs. The use of the signpost programs ensures the elimination of these inconsistencies. The cost of modifying all the signs in great britain to provide more accurate information is estimated at #22 million and the annual savings that are likely to result from this investment will be in excess of #150 million. It is possible that the annual saving in fuel and accidents alone will cover the total investment.(a) for the covering abstract of this volume see irrd 257235. For covering abstracts of other volumes see irrd 257174, 257182, 257202 and 257267.
Samenvatting