I know from personal experience and from residents' complaints that there can be long queues to get out of the O2 car park onto Finchley Road at certain times. So I raised this with Transport for London, who control the traffic lights at the junction. There reply is below.
I'll be interested to know if people think there's been an improvement.
Dear Councillor Moffitt
Thank you for your enquiry regarding the weekend operation of Finchley Road and in particular the exit from the O2 centre car park which gets busy on weekends.
This junction has been known to be problematic on weekends in the past and measures were put in place to allow for additional green time to traffic exiting the car park. Upon investigation it was found that the timings which had been in place to assist traffic exiting the car park were being hampered by a fault occurring with the vehicle detection on street. This fault is in the process of being fixed. In the meantime, new signal timings which increase the green time to the exit from the car park onto Finchley Road have been implemented as of Saturday 9 November.
We will monitor the new timings on street with the hope that this will ease the delay that you have experienced.