The sound of the local postie bike coming up the street will give way to the whirl of an electric trike as Australia Post rolls out its new mail delivery vehicles.

Key points: Australia Post estimates the volume of parcels has grown 10 per cent per year for the past three years

Australia Post estimates the volume of parcels has grown 10 per cent per year for the past three years It predicts that by 2020, one in every 10 items bought will be bought online

It predicts that by 2020, one in every 10 items bought will be bought online Australia Post first introduced motorbikes to its delivery fleet in the 1970s

Australia Post said the new electronic delivery vehicles (eDVs) had more sun protection and carrying capacity, and would keep posties safer from swooping magpies.

Mitch Buxton, the general manager of network optimisation for Australia Post, said people would start to see more of these types of vehicles coming out to deliver to houses.

"Our postie bikes in the past have been great workhorses, but they are limited in what they can carry," he said.

"It [the wave of new trikes] means there's a place for a postie many years into the future."

Online shopping growth means more to carry

Australia Post estimates that the volume of parcels has grown 10 per cent per year, for the past three years.

It predicts that by 2020 one in every 10 items bought, will be bought online.

So posties have had to adapt.

"We're not really carrying as many letters as we used to and we're starting to see more parcels," Mr Buxton said.

"These are designed so that we park on the footpath and then service our parcels to the door."

The trikes were trialled in Tasmania in 2017, and the first wave of the new fleet is being trialled in Rockhampton, central Queensland.

Australia Post started using the updated Honda in 2018, which are only available to official posties on some websites. ( Supplied: The Honda Shop )

50 years of postie bikes

Honda C110x are the most common delivery bikes, rolled out by Australia Post in 2018.

The bikes are only available to Australia Post contractors, meaning only used bikes are able to be bought by the general public.

They have a modified seat area and exhaust to typical two-stroke motorbikes, modifications experts say are in place to improve postie comfort.

The familiar sight of the postie on a bike. ( Flickr: Vanessa Pike-Russell )

Australia Post first introduced motorbikes to its delivery fleet in the 1970s, with the Honda CT90.

With the new e-trikes, Australia Post has also ordered a new fleet of 4,000 electric pushbikes.

Posties who pedalled

The new vehicles are a world away from what Rockhampton man Michael McCabe remembers from his time as a postie in 1970.

"You had to bring your own bike but you were given a Postmaster General bag, which is now called Australia Post of course," Mr McCabe said.

"I was 'lucky' to be given the run that went all the way from Davis Street in Allenstown all the way out to Blackall Street, over all the hills … probably 10 to 20 kilometres.

Michael McCabe delivers mail in Rockhampton during the Christmas mail rush in 1970 on his push bike. ( Supplied: Michael McCabe )

"So by the time I'd done that half a posties run I'd pedalled many, many, many steep hills.

"It was all pedal power back then."

Despite the physical challenge, Mr McCabe has fond memories of the job.

"My favourite thing were the lovely older ladies on Agnes Street who would always have a glass of cordial waiting for you when you got to the top of the hill.

"I also got to know many dogs."

Speed and terrain an issue for trikes

Despite their health and safety benefits, e-trikes have some limitations, according to Australia Post.

"They can't go everywhere, they do a certain speed and can go on certain terrain," Mr Buxton said.

"What we're doing now is going through our entire fleet and all of our rounds and we're making assessments and making sure that we're introducing vehicles that are fit for purpose for those types of conditions," he said.