Passengers will pay about $5 to travel between Perth Airport and the CBD when the Forrestfield Airport rail line opens after the State Government pledged to subsidise fares.

The Public Transport Authority confirmed yesterday it would not impose a surcharge on airport line fares when it opens in late 2020.

The decision means passengers will pay only a standard, two-zone fare to travel between Perth and the Airport Central station that will open at the same time as the line.

As of July 1, this will amount to $4.80, or 70¢ for students, although with inflation it is likely to rise slightly by 2020.

PTA spokesman David Hynes said it was common for other cities with airport rail lines to impose extra charges but he declared Perth would not.

“There are no plans to put in place an airport train station surcharge like many other cities around the world, so fares to the airport will be on a distance basis as per the normal Transperth zonal system,” he said.

But the move will add to the Government’s recurrent spending budget, which Treasurer Ben Wyatt revealed last week will blow out by $40 million a year thanks to the cost of running the airport rail line.

By keeping fares at the standard price, taxpayers will wear about 70 per cent of the cost of trips between the city and airport.

According to the PTA, the $1.86 billion Forrestfield Airport line is expected to carry an average 20,000 trips a day once it is fully running “by 2021”.

It said most of these trips would involve people getting on or off the train at either Redcliffe or Forrestfield stations, with 6100 trips a day forecast to be generated by airport passengers at first.

The number of trips to or from the airport is predicted to almost double by 2031 to 11,000 a day, while overall traffic on the line is forecast to grow to 29,000 daily trips.