Start early if I need to use it, most of my work is heading East into London so don't touch it, but do have to deal with A40 or A4 or A316 going into town, which can make the M25 a breeze mate.
Working in Brixton at the moment so having to deal with Wimbledon traffic !!! it's so much easier when we clean there, a couple of weeks ago no real traffic headaches.