Duration and Frequency of Seasonal Traffic Counts

Abstract

Presented in this paper is an investigation of areawide seasonal traffic counts (STC) that are undertaken by all state highway agencies throughout the United States and in several other countries. The current practice of STC programs is very diverse and there is a little evidence of major research efforts in this area. A large number of permanent traffic counter (PTC) sites are studied in order to rationalize the length and frequency of STC schedules. A proposed method described in this paper can be used to assign STC sites to one of the PTC groups for estimation of traffic parameters. An index of assignment effectiveness is developed to evaluate the appropriateness of alternative STC schedules. Another criterion is suggested to ensure whether a given STC schedule provides a seasonally balanced traffic volume sample. Effect of the road type on the length and frequency of counts is also studied. A number of alternative STC schedules are suggested to be used by highway agencies for cost‐effective traffic monitoring.