Spotted...

Top-tip: escape the madness, do a cheeky left into Duncan Street by the Foxtons at the end of Camden Passage, left by the York. Go right onto Colebrooke Row, cross City Rd and Goswell Street with the nodders using the bikelane/crossing and sneak left back onto St John Street and you've skipped the whole gridlocked mess in a few seconds.

That's good if you're coming down Upper Street, although you can also turn down the streets around Cross Street and get onto the Essex Road earlier, and the best place to turn into Colebrooke Row is then via St Peter's Street. (I don't like the blind corner outside the arts shop in Colebrooke Row itself.)