As a part of the evaluation of the Stockholm trials, the traffic volume in April 2005 will be compared with the traffic volume in April 2006. The results from the before study is presented in this paper. The total number of vehicle-kilometres produced within the inner city of Stockholm and in Stockholm County was estimated, both for the morning rush hour period (between 6 am and 9 am) and the full twenty-four hours. Tuesdays, Wednesdays, and Thursdays were here regarded as weekdays. The estimated traffic volume includes all motor vehicles, except mopeds and motorcycles. The estimation of the traffic volume in the inner city is based on a survey where traffic flow has been observed at randomly selected road sites. The results are presented with 95 per cent confidence intervals.

• Weekday 2 185 000 km +/- 153 000 km
• Morning rush hour 387 700 km +/- 31 900 km

The corresponding estimates for the County are calculated with a model-based method where the results have been adjusted to observed traffic flow. This method does not provide confidence intervals; therefore, only estimates of the total number of vehicle-kilometres are presented.

• Weekday 24 320 000 km
• Morning rush hour 5 235 000 km