During the period may to September 1993 data about speeds on rural roads were collected 3 days per month in about 80 points all around Sweden. These points are chosen in order to be representative for traffic on the state roads in Sweden. At each of these points the number of cars, the number of lorries, the speed of cars and trucks are registrated continuously the whole year. To obtain good data-quality routines were changed a little during the 5 month period. Sensors and other equipment were controlled more frequently then before. Due to low quality data from 1 month in 1 point could not be used. When looking at cars on the cross-sections with the highest speed limit we find the following results for cars for straight and level roads: a) On motorways with a speed limit of 110 km/h the mean speed is measured to 109 km/h. On a two-lane road with a width of 13 m and speed limit 110 km/h the mean speed is measured to 106 km/h, and with speed limit 90 km/h, 96 km/h; b) For lorry without trailer we found 94, 91 and 86 km/h respectively; and c) For lorry and trailer we found 84, 83 and 81 km/h respectively. It ought to be mentioned that all these figures come from points with traffic flow below the flew where queues begin to reduce the speed. Compared to 1992 the figures for different cross-sections show the same or a little lower values. For cars the difference is measured to - 0.1 km/h + 0.6. (A)
Abstract