Double-decker buses: London has them, Hong Kong has them and next month Melbourne will get them too.

Or rather, it will get one double-decker bus initially, operating in tandem with the new Regional Rail Link, with the prospect of more buses to come in future if there is enough demand.

Public Transport Victoria is considering using the high-capacity bus to shuttle passengers between brand new railway stations at Wyndham Vale and Tarneit, which will open on June 21, and stations on the Werribee line.

It will be operated by CDC Victoria, which has routes in Melbourne's west, Geelong and Ballarat, which will all be served by the new Regional Rail Link. It also operates out of an Oakleigh depot in Melbourne's east.  

The bus, which will initially run as a trial service, has 88 seats and capacity for 111 passengers. It is yet to be officially unveiled, but is on display this week at the AusTech Expo at the Melbourne Exhibition Centre.

The bus was designed and manufactured in Dandenong by local bus body builder Volgren, which employs about 250 staff at its Dandenong plant and 500 Australia-wide.

The company also exports double-decker buses to Singapore and Hong Kong, and articulated or "bendy buses" to Japan.

Volgren chief executive Peter Dale said double-decker buses were iconic in other cities but a largely untapped form of public transport in Australia. He expected the bus to be embraced by passengers.

"It has around 90 seats so when people get on a bus and travel a bit further, it is significantly more comfortable and safer," Mr Dale said. "Our expectation is that this will be a very, very successful trial."

Daniel Bowen, a spokesman for the Public Transport Users Association, said overcrowding was a problem on some bus routes in Melbourne, including university shuttles and Smart Bus routes, though not necessarily around Werribee.

He said patronage might increase next month after the Regional Rail Link opens and people in growth area suburbs such as Tarneit and Wyndham Vale get a much more attractive rail service into the city.

"There are certainly a number of very busy bus routes around Melbourne that do suffer from overcrowding, so generally it's good that they are looking at options for high-capacity buses," Mr Bowen said.

Bus routes and timetables around Werribee will be revamped when the link opens on June 21 to better co-ordinate trains and buses. Many routes will be straightened out so they are more direct and run down fewer back streets.

The $3.65 billion Regional Rail Link – a new 45-kilometre line between West Werribee and Southern Cross Station – will significantly increase capacity for V/Line and Metro services west of Melbourne's central business district.