Urban roads
Urban roads

Eva­lua­tion of speed moni­to­ring mea­su­res

Fixed speed cameras are very effective in reducing accidents. That is one of the findings of a new study by the German Insurers Accident Research.

Driving at “inappropriate speeds” is the most frequent cause of traffic accidents in Germany. Thus, speed is a contributory cause to approximately one in eight acci-dents involving injury caused either solely or jointly by drivers of motor vehicles (13 %) and this figure is twice as high for accidents involving fatalities (28 %). A re-search project conducted by the German Insurers Accident Research investigated whether fixed or mobile speed cameras can help to improve road safety. For this purpose, the authorities were questioned, extensive speed measurements were car-ried out and the accident occurrence before and after the installation of speed moni-toring systems was compared. Very different results were found for fixed and mobile speed cameras.

Fixed speed cameras are very effective if they are located in the right places

 At fixed speed cameras, the speed limit (plus tolerance) is respected at all times by practically all drivers. Previously observed occurrences of speeding are effectively reduced. The effect of fixed speed cameras is restricted to a relatively short area. In general, the speed-reducing effect falls off as little as 200 m before and after the protected area. On 30-km/h stretches, in particular, fixed speed cameras have only a very localized effect. The installation of fixed speed cameras considerably reduces accident numbers in the immediate vicinity of the installation (100-m radius), in par-ticular at intersections without traffic lights and at bends on open stretches of road. Although a slight increase in longitudinal traffic accidents and rear-end collisions was observed following the installation of speed cameras, this was far outweighed by the general reduction in accident numbers. 
Many fixed speed cameras are installed in locations with no noteworthy accident occurrence.

Recommendations for fixed speed cameras

Fixed speed cameras should primarily be installed in locations where the accident occurrence merits this. Prior to installation, it is necessary to check whether any noteworthy levels of speeding occur and whether the speed limit is displayed in an appropriate way given the specific conditions at the location. Because the effect tends to be localised, the exact location of the installation must be carefully planned. The distance over which the effect persists can also be increased if road users are able to identify the purpose and relevance of speed monitoring. Fixed speed camer-as are suitable as either a locally effective immediate measure (intermediate meas-ure) or as a permanent measure. In addition it should always be checked whether there are any local building-related or operational shortcomings that can be elimi-nated.

The Effect of mobile speed cameras is restricted to the monitoring period

The effect of mobile speed cameras is much less than that of fixed speed cameras. Even during the monitoring period, the speed limit was still not respected by many road users. The speed-reducing effect of mobile speed cameras is restricted to the monitoring period. For methodological reasons, it was not possible to assess the effect of mobile speed cameras on accident occurrence. Further research will be necessary to ascertain this.


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