Perth bus drivers will be able to turn away riders looking to buy fares with $50 or $100 notes under new laws, amid a crackdown on freeloaders exploiting a lack of change held on board.

The changes, which come amid several new rules for commuters, have been introduced by the Public Transport Authority to give drivers the power to stop riders boarding if they only have a large-denomination bill. In some cases, riders who board a bus with a $50 or $100 bill are given a free ride because the driver does not have enough change.

PTA spokesman David Hynes said there had been a number of repeat offenders who had tried to board a bus with a $50 or $100 bill, in a bid to get a free ride.

“It has been Transperth policy for more than a decade that drivers do not accept $50 or $100 notes because of difficulties managing change, and safety implications for drivers needing to manage larger sums of cash,” Mr Hynes said.

“SmartRider, which is now used by 90 per cent of passengers at peak hour, also means the use of cash on board services is extremely limited. The policy has been signposted on buses for years, but this change now formalises the ability of drivers to refuse travel to people who repeatedly tender large notes in an attempt to gain free travel.”

Other new rules include the closure of a legal loophole which meant bus drivers were not able to issue infringements to people for not having a valid ticket. “Not travelling with a valid ticket is an infringeable offence but drivers are unable to issue infringements, and have no power to refuse travel,” Mr Hynes said. “The regulation change means bus drivers can now refuse travel.”

Also included in the wave of changes is a new ability for bus drivers and train platform operators to turn away passengers once a bus or train reaches capacity.