Starting 2008, the Swedish Transport Administration performs a total review of the speed limits on the entire state road network in Sweden. This study presents the first results from speed measurements made before and after the changes of speed limits in Phase 1, the national road network. The results shown are real changes of mean speed and time distance between vehicles on the following road types: 1. Motorways 110à120 km/h; 2. 2+1 roads 110à100 km/h; 3. 2+1 roads 90à100 km/h; and 4. Rural roads 110à100 km/h. In order to evaluate the speed changes, a before-and-after study was performed. This study was conducted as a sample survey where speeds were measured in a random sample of 10 points per road type. The results show that mean speed of cars increases by about 3.5 km/h when the speed limit increased 10 km/h. This applies both to motorways where speed limits have increased from 110 km/h to 120 km/h and the 2 +1 roads where the limit has been increased from 90 km/h to 100 km/h. Where the speed limit has been lowered by 10 km/h the mean speed decreased by 2.3 km/h on 2 +1 roads and 2.0 km/h on rural roads. All changes are significantly different from zero. The actual changes are similar to results from other studies. Studies of controls where speed limit not has changed indicate that there has been no general change in speeds on the national road network during the time of measurement. In the case of percentage speed violations we see an increase by about 20 percentage points when the speed limit is lowered and a decrease of the same amount when the limit is raised. This is due to the fact that drivers have not adapted their speeds in full after the new speed limits. The share of traffic with short time-distance (under 5's) has not changed, indicating that accessibility has not deteriorated. For trucks with trailers the speed limit 80 km/h applies both before and after the changes of speed limits. In general, there have been no significant changes in mean speed for these vehicles. Trucks without trailers consist of busses as well as light and heavy trucks. Here, the results show that when the speed limit has increased, the actual speeds have increased, but there are no significant reductions when the speed limit decreased. Since this group is mixed with respect to vehicle speed, it is difficult to interpret the results. The evaluation is continuing and speed measurements on roads that changed speed limit in Phase 2 (other state roads) will be reported in 2011. (Author/publisher) This report may be accessed by Internet users at http://www.vti.se/en/publications/evaluation-of-the-new-speed-limits--t…
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