A Gold Coast bus operator says it is "beyond luck" no one has been seriously hurt or killed from the 100 attacks on its buses in 13 months.
In 2016, 83 buses were struck by projectiles - three times more than the 28 incidents of 2015 - and two more incidents on Thursday night mean 17 attacks have already occurred in 2017.
Rocks and other items are being thrown, causing significant damage such as shattered windows and resulting in a bill of more than $110,000 for the past year's attacks.
Surfside Buslines general manager Martin Hall says it is only a matter of time before there are fatal consequences.
"We're beyond luck. Every day these drivers are running the gauntlet. The luck's going to run out very, very soon and there'll be an injury to either one of our bus drivers, a member of the public or an asset of ours involving other vehicles," he said.
"It's a ticking time bomb."
Surfside says most attacks occur on the southern end of the Gold Coast, particularly in the suburbs of Varsity Lakes, Burleigh Heads, Palm Beach, Elanora and Currumbin.
CCTV footage shows bus drivers are being targeted in most attacks.
Transport Workers Union branch secretary Peter Biagini says Gold Coast drivers are increasingly concerned for their safety while driving on night routes.
"It's just totally unacceptable for this to continue to happen," Mr Biagini said.
"(Drivers are) extremely concerned, not only for their own welfare ... but also for the public that use the service."
Youths are suspected of being behind most attacks, and police say anyone arrested for throwing projectiles at buses will face charges.
RECOMMENDED STORIES
'Justice for Manmeet' rally at court
"It's not just wilful damage. The consequences to this are life-endangering," Acting Inspector Ben Nielsen said.
"You can choose your actions but you can't choose your consequences ... think twice and don't do it."
In October last year, an Indian migrant bus driver was killed while on duty in a southern suburb of Brisbane.
Communities across Australia held vigils to commemorate the 29-year-old man.
