Or, knowing Sheffield, excessive gradient (which amounts to the same thing, but is perhaps more symptomatic of poor judgement rather than deliberate recklessness).
I remember taking lengthy detours to avoid steep descents in slushy conditions, on account of the Fiat Of The Apocalypse's tyres being almost as fit for purpose as its electrical system. Mind you, this was a car that could barely climb Conduit Road in the dry.