There have been more than 200 assaults on Dublin Bus drivers over the past two years.
According to details released under the Freedom of Information Act, 107 drivers were attacked on duty in 2018.
The number reduced slightly last year, to 100.
"I just think it's an appalling indictment on the type of culture that's prevalent across society," said Dermot O'Leary from the National Bus and Rail Union.
"That's probably doesn't include the stone-throwing and rock-throwing and the taking of drugs and smoking of heroin on buses that are reported by a lot of the local papers."