A bus crash survivor said the Mayor has "learnt nothing" from the Croydon tram crash, as research shows one in six bus drivers fell asleep at the wheel last year.
Critics of TfL’s safety record said the Mayor has failed to learn lessons from previous accidents.
Seven people died when a tram derailed at Sandilands in 2016, and a further 62 were injured – the tram driver is believed to have briefly fallen asleep at the wheel.
Tom Kearney, a businessman and bus crash survivor, who campaigns on bus safety, welcomed the report, but said it revealed the system's failures.
Mr Kearney said: “TfL recognise that they’ve got a problem, and buses cause a huge amount of collisions and deaths.
“But they are knowingly running a system that puts the speed and frequency of buses above people’s lives.”
London buses cause a disproportionate number of deaths and injuries on the streets of the capital, accounting for 14 per cent of pedestrian deaths while making up less two per cent of traffic.
The study commissioned by Transport for London (TfL) has more than 20 per cent of drivers fight sleepiness multiple times a week.
The report – which surveyed over 1,000 bus drivers – said demanding shift patterns and long work hours increased fatigue.
TfL has now earmarked £500,000 to tackle driver exhaustion.
And from next year, the transport network will require all bus companies in the city to have a safety management policy – something not currently required.
Deputy Mayor for Transport Heidi Alexander said TfL’s response was “the start and not the end” of efforts to reduce driver fatigue.
The publication of the report came as the union Unite – the biggest representative of bus drivers in London – organised a demonstration at City Hall to draw attention to poor working conditions.
Unite regional officer John Murphy said the Mayor had “done the right thing” by requesting the research, but that progress for drivers was “too slow”.
He said: “TfL must take decisive action and force bus operators to stop flogging their workers to the point of exhaustion.
“The safety of the general public and workers is being placed at risk because of fatigue being suffered by London bus drivers.”
Speaking at the drivers’ demonstration on Saturday, Sadiq Khan said the “world first” fatigue report was a step towards improving working conditions.
He said: “I’m really proud to be the son of a bus driver. What I’m not proud about is when I saw when I became Mayor the kind of conditions that bus drivers are working under in our city.”
He added: “For those who aren’t aware of the fatigue that bus drivers suffer it is eye-opening, and it should be a wake up call for Transport for London to do much more to improve the conditions of bus drivers.”
A spokesperson for the Mayor said Mr Khan was taking action to improve safety on London trams, buses and across the network.
She said: “Sadiq is committed to improving safety for staff and passengers across the TfL network. Nobody wants a tragedy like Sandilands to happen ever again.”