Unions have filed a complaint to the Ombudsman accusing the government of failing to ensure the safety of the city's bus services, saying their claim is backed up by the findings of a probe ordered by the administration.
Members of the Federation of Bus Industry Trade Unions, representing hundreds of drivers from the city's three biggest franchised bus operators, chanted "We don't want drowsy driving" at a protest outside the Ombudsman's office in Sheung Wan.
They filed a formal complaint against the Transport Department, accusing it of a "serious dereliction of duty".
The unionists said an independent committee review into franchised bus services, ordered after a deadly crash in Tai Po early last year, has pointed out that allowing drivers to work shifts as long as 14 hours increases their chances of fatigue.
They complained that they had warned the government about this problem long ago.
Tsang Chiu-man, the executive director of the federation, said the Transport Department must cap the number of hours bus drivers can work, and the review's findings represent strong evidence that such a move is needed.
Tsang said the Transport Department has also been ignoring requests by drivers for road tests on a longer model of bus used in places on Hong Kong Island.