might refer to this, from The Cycling Lawyer.
… I moved on to ???total tolerance??? which is how I see enforcement of advanced stop lines. The statistics on Simon???s computer did not break down how may traffic light offences were advanced stop line (only) but he did agree that the figure would be ???zero or close to zero???. He felt that since this was an endorseable offence the penalty was disproportionate to the ???inconvenience??? caused. I felt that these boxes potentially were there not just for convenience but for safety and were being ignored as a matter of routine by many drivers who knew there was no risk of enforcement action. Simon did think it was rather unpleasant for a motorist to have an officer give him a warning in the presence of other ???intimidating??? cyclists. … Apparently enforcement of advanced stop lines might happen in the future, particularly if it became a separate non-endorseable offence.