New answers tagged europe
This sign is also common in france; it means no entry except for bicicles.
In UK it would not be allowed unless there was an additional sign stating otherwise. The same rules apply to all vehicles on the road. I don't think Google maps necessarily actually always accurately provide the best route. For example from my house it would better to get off the bicycle and cross the park on foot than cycle around the roads to get to the ...
In France, the sign was made explicit and a special contraflow lane was added. All roads where you can cycle against the flow on a one-way road is marked with this sign: This is a very common occurrence in cities where cycling is popular! See this wikipedia article for a bit more background, although the french version is more extensive.
There is also a Czech version of allowing you to bike 'the other direction'. Biking against the one way direction is not much of a crime here and where the traffic is low, it's usually tolerated. I'd advise against biking the wrong direction in traffic heavy places like city centers, though, even when it's allowed. These signs (and corresponding ...
Just to add to FatHippos answer: The same applies to Germany. In my home town there was a survey of all one-way roads between 2004 and 2010, which resulted in most of them now being open for bikes in both directions. These roads are also marked explicitly with a sign like the one you describe.
In Holland, were I assume cycling is much more common than in Poland, the kind of traffic sign you describe are abundant (see example, "uitgezonderd" is Dutch for "except for"). And cycling against traffic in a one-way street without the sign is indeed illegal. The same rules seem to apply in Poland, though I cannot find a reliable source for Polands cycling ...
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