Danes report accident fall after speed limit rise

Motorists association the Alliance of British Drivers has seized on a newspaper report that accidents have gone down on Danish single carriageway roads where the speed limits have been increased.

The Copenhagen Post reported that accident levels have  fallen on stretches of single carriageway rural roads where the speed limit was raised from 80 to 90km/h (50mph to 56mph) in 2011 by Danish road directorate, Vejdirektoratet.

Final results of the trial are due next year but the preliminary results raise questions about the DfT’s speed limit appraisal tool that helps local authorities set speed limits (LTT 25 Jan 13). The tool’s guidance explains: “Where a speed limit scheme reduces speeds, the tool will always forecast reductions in accidents. Conversely, where speeds increase, accidents are also forecast to increase.”

The Copenhagen Post said the slowest drivers had increased their speeds but the 15% fastest vehicles were now driving a little slower. 

The paper quoted Rene Juhl Hollen, a Vejdirektoratet spokesperson, saying: “If there is a large difference between speeds then more people will attempt to overtake, so the more homogeneous we can get the speeds on the two-lane roads, the safer they will become.

“It looks like we’ve found the appropriate speed on those stretches of road, so we will reduce the speed differentials and consequently decrease the number of people overtaking.”

The ABD said the report supported its argument that the 85th percentile speed is the most appropriate method for setting speed limits. “These findings vindicate what the ABD has been saying for years, that raising unreasonably low speed limits improves road safety by reducing speed differentials and driver frustration,” said ABD joint chairman Brian Gregory.

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