A cashless ticket system being introduced to coincide with paid parking in Perth train station carparks will also be the major weapon in a crackdown on the hundreds of motorists who use the carparks but do not catch trains.
Transperth has become aware of drivers who leave their cars in train station carparks, take their bicycles out of the boots and ride into the city.
Others park and then go to a nearby shopping centre.
There is also at least one company whose staff park at a station on the Mandurah line before being picked up by a private charter bus and ferried many kilometres to work.
"The problem became so bad in Fremantle, in particular, that we had to permanently disable the ability to pay for parking with cash and link it only to SmartRiders," Public Transport Authority spokesman David Hynes said. "This means that we can make sure actual public transport users are the ones benefiting from the carpark."
The ticketing system, known as SmartParker, works by linking a passenger's SmartRider card to their vehicle registration details. It allows them to pay for parking by "tagging on" to a machine. The passenger can then go straight to a station without having to return to the car to display a ticket.
The passenger must then tag on to a Transperth train or they will not be able to tag on to park the following day.
"We expect this will open up hundreds, if not thousands, of bays for genuine public transport users because it weeds out any people who park in our carparks but don't use our services," Mr Hynes said.
"We accept that there is strong demand for parking and these changes may well help to moderate demand."
Fremantle will continue to have cashless carparks and Swanbourne and East Guildford stations will also be cashless because they have been identified as having many users who park but do not catch a train.
Carpark attendants will patrol and use a hand-held device to scan registration plates to check on payment.
There are about 20,000 train station carpark bays on the metropolitan network, with about 5875 already requiring payment.
Paid parking at $2 a day will be introduced for all other bays from July 1.