It is one way from The Fieldings onwards. You can turn left down the hill from the Fieldings but no further up. It is clearly signposted at the top and all the way down.

I caught a black cab coming down there last year who basically told me to f off when I had a go at him. Took his number and reported him to the Hackney Carriage office who told me he had probebly "made an honest mistake", as if 4 no entry signs and writing on the road are hard to miss.