A commuter group says Dublin Bus needs to get better at letting passengers know its heard their complaints.
Figures show more than 14,000 complaints were made to the company last year, with express routes drawing the most criticism.
The 25X UCD Belfield to Lucan and the 39X Burlington Road to Ongar topped the list of the most complained about Dublin Bus routes in 2018.
Figures from the National Transport Authority show, while Dublin Bus took more than 14,000 complaints last year, that figure was a drop of 4% on 2017.
More than half of the complaints related to 'service experience', with a quarter about 'staff issues'.
Kevin Carter from the Dublin Commuter Coalition suspects many unhappy passengers don't bother formally complaining.
"A lot of times when people report things on Twitter, they are directed to a web form instead of Dublin Bus dealing with the complaint they've already been given".
He suspects many of those people who are re-directed to "a huge web form" don't bother to fill it out, meaning their complaints are not counted.
