Relative risks of crossing an intersection. Crossing on a set-back cycle path has been found to be up to 11.9 times more risky than straight crossing on a road with a bike lane. Note that off-set separate paths are often only provided on one side of the road, thus making the 'contraflow' movement with its high accident risk legal, in some jurisdictions officially required.
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Segregated facilities and accident numbers
For urban roads with many junctions, accident analysis suggests that segregated cycling facilities are likely to produce a net increase in the number of collisions. These conclusions are supported by the experience of countries that have implemented segregated cycling facilities. In the United States, UK, Germany, Sweden, Denmarkand Finland, it has been found that cycling on roadside urban cycle tracks/sidepaths results in up to 12-fold increases in the rate of car/bicycle collisions. At a 1990 European conference on cycling, the term Russian roulette was used to describe the use of roadside cycle paths.
In Helsinki, research has shown that cyclists are safer cycling on roads with traffic than when using the city's 800 kilometres (500 mi) of cycle paths. The Berlin police and Senate conducted studies which led to a similar conclusion in the 1980s. In Berlin 10% of the roads have cycle paths, but these produce 75% of fatalities and serious injuries among cyclists. In the English town of Milton Keynes it has been shown that cyclists using the off-road Milton Keynes redway system have on a per-journey basis a significantly higher rate of fatal car-bicycle collisions than cyclists on ordinary roads. Cycle lanes and bike lanes are less dangerous than cycle paths in urban situations but even well-implemented examples have been associated with 10% increases in casualty rates.