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I suspect it's just inherited from the "rules of the road" extant before most road traffic was motorised and before most roads were widened to 2 lanes. On single-track roads e.g. in Scotland, it's...
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I suspect it's just inherited from the "rules of the road" extant before most road traffic was motorised and before most roads were widened to 2 lanes. On single-track roads e.g. in Scotland, it's...