Buses caught in the yellow box trap
It is one of the great scourges of London's roads - the irritating sight of a bus blocking off a vital crossroads.
But embarrassingly for Transport for London, when it decided to target people who block yellow box junctions, it found one in 10 offenders were its own bus drivers. At least two of its buses blocked a junction every hour.
Warning notices and more than 200 £100 fines were sent to bus companies whose vehicles were caught on CCTV cameras.
Today new figures reveal bus drivers have got the message - they are now only responsible for 0.03 per cent of offences, a drop of 84 per cent.
Now TfL bosses hope the blitz will have a similar effect on motorists and help to cut congestion across the capital.
"Our position was that there is no excuse to block a junction just because you have a long vehicle, and the message has got through," said Jeroen Weimar from TfL. "It is a huge drop and shows that the trial has already resulted in a dramatic change of behaviour, at least by one section of drivers.
" We have found that bus performance has not dropped off at all; blocking junctions was not getting them to their destinations any faster. In fact it was probably causing more delays."
TfL insists it is too early to say whether motorists are being deterred too.
But Mr Weimar admits: "Early indications are that compliance among motorists is very good." To date TfL has issued 5,115 fines for blocking junctions at the 25 junctions it is monitoring during the nine-month trial.
It means about 393 drivers a week are now being fined, compared with 721 a week in the first three weeks of the scheme, when warning letters were sent out instead of penalty notices.
TfL bosses say they are also encouraged by the low proportion of motorists who protest against "unfair" yellow box junction fines.
Fewer than one in 10 motorists fined has complained and only 1.6 per cent have taken appeals against fines to independent adjudicators.
Research for TfL found more people were becoming aware of the law relating to yellow boxes. A NOP World survey found 83 per cent of people were aware of yellow box regulations while 97 per cent knew the rules on bus lanes.
Encouraged by TfL's results, four other councils - Camden, Ealing, Croydon and Newham - are running their own trials in yellow box junction enforcement.
