Sydney Trains has begun trialling a new security device designed to catch vandals in the act.
The electronic chemical sensor, known as the Mousetrap, detects vapour given off by spray paint and alerts Police Transport Command (PTC).
A number of trains have already been equipped with the sensors, leading to the arrest of more than 30 offenders to date.
Mousetrap, which can even detect vandals using marker pens, works alongside traditional CCTV to record and catch offenders.
Sydney Trains said that removing graffiti around its network costs the operator in excess of $30 million a year.
“Our customers hate it – it’s one of the top customer complaints and cleaners work hard to remove about 11,000 tags from trains each month,” said Sydney Trains chief executive Howard Collins.
“We know it’s early days for Mousetrap but its success has been in allowing Sydney Trains to move from a strategy of removing graffiti to one where we stop it as it happens.”