Why? Well, how else do you get from Kingsdown to Gloucester Road when Cotham Brow is closed.
Indeed, two days later, the no-entry signs at this end (and the one-way signs at the other) were taped over. so when there were head-on conflicts such as happens below, both sides would feel they were wronged..
Perhaps then, just as bike lanes follow unofficial cycling routes, these motorists are leading a way in defacto actions which will eventually be authorised.
