In order to be able to convert vehicle-kilometre data from traffic counts into kilometres travelled, the daytime occupancy of seven vehicle categories on six different road sites has been counted one week a year in May. The seven categories are: cars, mini-buses, delivery vans, lorries, motorbikes, mopeds, and bicycles. The six road sites are: a motorway, a regional road, a scenic road, and three points inside the built-up area. It is doubtful if the sample is representative; the main aim was to cover the various types of road and, by using the same method, to be able to carry out trend analysis. Occupancy is declining as ownership rates increase for most of the vehicle categories. More than half the cars have no passengers whereby the average occupancy lies considerably below 2. Minibuses, with up to 9 seats, have an average occupancy of just below 2. For the other types of vehicle the averages are: delivery vans - less than 1.5; lorries ca. 1.25; motorbikes - less than 1.2; mopeds ca. 1.1; and for bicycles — less than 1.05. There are considerable variations in time and space: at weekends, especially Sundays the occupancy is higher than during the week; the scenic route has the highest occupancy, followed by the motorway - the regional road has a much lower occupancy and is similar to the roads within the built-up area.
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