One in 20 (5%) London bus drivers have crashed in the past year due to fatigue, according to a new survey.
The poll also suggests that 36% have suffered a “close call” due to extreme tiredness.
Researchers believe operators and Transport for London (TfL) are likely to be unaware of the effects of fatigue and sleepiness, as more than three-quarters (77%) of those who said they were in a crash believed their employer did not know the cause of the accident.
The survey of 1,353 London bus drivers was part of a report led by Loughborough University and commissioned by TfL.
Several factors were found to be the key causes of fatigue among bus drivers, including irregular shifts, quality and quantity of sleep, overall health of drivers, disciplinary culture and mental overload while driving.
The Unite union has previously warned that bus driver fatigue is at a “chronic level” which is affecting safety.
TfL said all new London bus contracts from summer 2020 will require operators to have “robust systems” to reduce the risk of driver fatigue.
It will create a fund worth half a million pounds for firms to develop a range of new solutions to the problem.
TfL’s director of bus operations Claire Mann said: “This report builds on the issues that Unite the union raised, and allows the whole industry to go one step further.
“With the evidence from this study, we will require bus operators to have fatigue risk management systems and more formal fatigue training for managers.
“We’re also working with the bus operators and Unite to create a programme to gather ideas for how we can further respond to the report.
“It is through working together across the industry that we can address this vital issue and make our buses lead the way when it comes to reducing risk on the roads.”
An investigation into a tram crash in Croydon, south-east London in November 2016 found that driver Alfred Dorris possibly drifted into a “microsleep” before speeding round a sharp bend and coming off the tracks.
Seven people were killed and 51 were injured.