a review of rural traffic-counting methods in developing countries

this report reviews methods of rural traffic counting currently used in developing countries and examines the accuracy of the resulting flow estimates. the results of a questionnaire survey among a sample of developing countries suggest that decisions on the duration, frequency, and timing of counts are at present arbitrary. consequently, estimated daily traffic flows can rarely be expected to lie within + or - 30% of the true value averaged over the whole year. although repeating counts at intervals throughout the year increases the accuracy of traffic estimates, this is achieved only at a disproportionate increase in cost. it is concluded that for any appreciable increase in the accuracy of rural traffic estimates much more needs to be known about the magnitude and causes of the variations in flow. this requires that automatic traffic counters be used on a wider scale than at present (a).