The results of the traffic counting programme operated by the environmental research unit of my Department on regional and county roads in the ten counties in question for 1988 (the latest year for which data are available) are set out in the following table. Similar counts are available (for the same count locations) for 1980, 1986 and 1987.
The traffic count was carried out by roadside enumerators who visually classified the traffic into the classes (bicycle, motorcycle, car, van, tractor, bus, rigid-truck, articulated-truck, truck and trailer or miscellaneous). For each count location, the table lists the total number of each of these vehicles classes observed by the enumerator during the seven hour period 9 a.m.-1 p.m. and 2 p.m.-5 p.m. on the stated date and the total of these observations. The right hand column lists the estimated AADT (24 hour vehicular volume on an average day) obtained by converting the seven hour volume to 24 hour volume using expansion factors obtained from information given by mechanical traffic counters. The count locations are identified by their road numbers as listed in the local authority's road schedule or, in the case of counts in County Dublin, by road name.
Since the count locations were selected as part of a sampling system designed to provide a single estimate of total vehicle miles of travel on all regional and county roads in the country and since separate sample frames were not set up for regional and for county roads, the counts listed in the table do not give reliable figures of the average traffic counts or the average volume of vehicles per day on regional roads or on county roads in individual local authority areas.
