This report contains a general presentation and results of a statistical survey on speeds and time gaps that was conducted by the Traffic Survey Centre at the Swedish National Road Administration between June and September 1999. The survey was conducted at measurement locations that were selected through two independent probability samples: one for state authority roads and one for local authority roads in urban areas. Measurements were performed at each selected location during a random 24 hour period. Data was collected through the registration of axle passages using two pneumatic road tubes connected to the Meteor 2000 traffic analyser. The survey results are presented both for the country as a whole, as well as for each of the seven regional road management directorates of the Swedish National Road Administration and are specified for private cars and lorries with and without a trailer. An overall presentation including all types of vehicles is also given. The results with respect to speeds are presented as travel speeds, the proportion of the total traffic volume exceeding the speed limit and the average speeding violation. With regard to time gaps, the results are presented as the proportion of the traffic volume with a critical time gap, the average critical time gap for traffic and the average desirable increase in time gap in relation to the total volume of traffic. (A)
Abstract