FIRST ON 7: Graffiti vandals are leaving their mark more often on Sydney's trains and railway stations.
7News can reveal attacks are up 10 percent in just one year, and the Western line is the worse.
The clean-up is costing taxpayers $26 million dollars a year, and the behaviour of vandals is terrifying train drivers.
"We hear from drivers and guards that have rocks thrown at them, been assaulted and been ambushed," the Rail, Tram and Bus Union's Helen Bellette said.
In 2011, there were fewer than 11,000 incidents of graffiti or malicious damage on trains, but that has jumped to more than 12,000 last year.
The Western line is the worst with nearly 16,000 reports, that's more than four a day.
While the Inner West received 1011, North Shore 967, followed by the Illawarra with 850 and Central Coast lines 767.
The Opposition says the number of transit officers and police patrolling our trains and stations has dropped by around 300 in less than a year, from 750 to 450.
The Shadow Transport Minister Penny Sharpe said there are fewer patrols on our trains than ever before.
"I believe it is getting worse, I think when we see the figures for this year we'll see it's continuing to spike, people are constantly complaining," Ms Sharpe said.
"If [vandals] see the graffiti goes up and it doesn't come off they know they can keep doing it."
But the Transport Minister, Gladys Berejiklian, said the Government is taking a number of actions including boosting the police presence on trains.
"This is a problem that's been going on for years and years," Ms Berejiklian said.