Wetenschap - 26 mei 2011

Hardly any gain for cyclists on a 60 km/h road

The introduction of 60-km zones is a success. The suburbs have become a great deal safer. But the cyclist has nothing to gain from this, contends researcher Rinus Jaarsma.

Jaarsma (Land Use Planning) shows, together with the Dutch national road safety research institute (SWOV), how much safer country roads have become due to the 60-km legislation. Since the 1990's, 60 km/h has been the speed limit in the suburbs. Signs, altered road markings and raised junctions have compelled motorists to reduce their speed.
All such measures were really necessary. Statistics have long pointed out that nowhere is the traffic more dangerous than in the countryside. The so-called accident risk on country roads is ten times as high as that on highways. The chance of being hit by a vehicle for every kilometre of road travelled is ten times higher in the Binnenveld than on the A12. In absolute figures: every two million kilometres travelled on a country road has caused one death. That the highways have more casualties is simply because more vehicles use them: the power of big numbers.

A quarter less accidents
It is easy to understand why highways are relatively safer. Jaarsma: 'Although the vehicles there move at high speeds, they travel in the same direction, within their own lanes, have split-level crossings and gradual filtering in.' If collisions do occur, they are seldom head-on. All these advantages are absent on country roads, which are narrow, have traffic moving in both directions, and used by all kinds of vehicles differing greatly in speed and size. Country roads are in fact conflict zones.

Jaarsma and co-workers collected accurate data of accidents in twenty areas over a period of many years, from five years before the implementation of the 60-km limit till more than three years after. The figures, when placed next to control areas which have not been modified, produce surprising results. The number of accidents (involving casualties) has fallen by a quarter. At road junctions, the decrease is even 44 percent. The number of casualties has been reduced by almost the half and the number of deaths and serious injuries at junctions, by more than half.
 

The number of traffic accidents in the Netherlands has been decreasing for many years. There were 'only' 640 last year, of which a large part involved cyclists (162) and pedestrians (72). In these accidents, 246 car passengers lost their lives.
Nothing for the cyclist
These gains are much higher than expected. When the 60-km zones scheme was introduced, calculations then showed that accidents would fall by 10-20 percent, says Jaarsma. The actual decrease on all fronts is higher. It is not a coincidence that junctions have become safer, says Jaarsma. 'Refurbishing 60-km roads was low-keyed; costs had to be kept low. Expectations were that the most gains would be at the conflict points, these being the road junctions. Traffic charts have been drawn up for these, raising the attention span and reducing the speed.

But the success has brought with it a gloomy side. Jaarsma: 'The slow modes of traffic have not benefitted much. And they are present in great numbers. It seems to make no significant difference to a cyclist or someone on foot whether it's 60 or 80 km/h. You can in fact say that there's nothing here for the cyclist.' Why? Jaarsma does not know for sure. 'More cycling is being done, especially by the elderly. Moreover, there are more electric bicycles on the roads and these can go faster and further. But this is just speculation.'

Accidents Analysis and Prevention 43 (2011) 1508-1515; Making minor rural road networks safer: The effects of 60 km/h-zones; Rinus Jaarsma et al.


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