On a secluded circuit east of Brisbane, red, blue and white trucks lined up, side by side, waiting for fresh drivers to turn their keys.
But, as they did, the drivers heard little in response.
That's because these vehicles are some of the few battery electric trucks available in Australia, producing minimal noise and vibrations, no tailpipe emissions, and hauling as much as 44 tonnes.
But until recently the largest of these vehicles was not allowed on Australian roads.
Their manufacturer, Volvo, even had to apply for an exemption to show off one of the vehicles at a Queensland expo.
Two Australian states have this month changed weight laws to allow heavy-duty electric trucks on our roads, however, and the federal government changed restrictions on truck sizes to permit the use of battery-powered models imported from Europe.
Transport experts say the changes will allow more companies to invest in the technology, make significant cuts to emissions, and see the vehicles manufactured in Australia for the first time.
But some of the legal changes are temporary and they say more ambitious, widespread and permanent reforms are needed to make big changes to the country's biggest vehicles.
Volvo showed off its large electric trucks at the RACQ Mobility Centre in Cornubia, Queensland, on Thursday as part of a push to raise awareness of the vehicles that can now be deployed in NSW and South Australia.
After years of lobbying, both states have changed weight restrictions on electric trucks to allow an extra tonne over the front axle in South Australia and an extra 1.5 tonnes in NSW.
But both changes have been described as trials, with South Australia offering 12 months of use on prescribed roads and NSW allowing the change for two years.
National Road Transport Association Warren Clark welcomes the hard-won changes that he says could help put more efficient, environmentally friendly and profitable vehicles into the transport system.
But he says the changes do not go far enough as the low-emission vehicles deserve more than test drives in Australia.
"The policy change to allow an increase in the axle load to cope with the weight of batteries is a step forward but a far wider and comprehensive set of policies needs to be developed in partnership with the industry to provide certainty and drive investment," he said.
"A two-year trial does little to encourage investment – it needs to be made permanent."
Electric Vehicle Council chief executive Behyad Jafari says the state-based changes could be a stop-gap while states wait for national laws to catch up to the technology.
While the federal government's change to allow wider trucks of 2.55 metres rather than 2.5 metres will be permanent, the process of changing transport rules is a long one, he says, that is not designed to deal with significant technological change.
"I don't think there are any particular sticks in the mud on this issue but just by design it's a lengthy process," he said.
"The reason why this process usually takes years is because there are usually no big disruptions but this is a big disruption, the shift towards electric trucks."
Mr Jafari says electric heavy vehicles could deliver cheaper maintenance and running costs for logistics firms, as well as making vital cuts to transport emissions that will be needed for Australia to meets its 2050 emission reduction target.
"Trucks make up eight per cent of the vehicles on our roads but they account for about 16 per cent of cent of the emissions from vehicles on our roads," he said.
"Every truck that we move to electric, we're able to have an outsized impact on emissions."
One reason why transport authorities are trialling heavy-duty electric trucks is due to concerns their larger weights could impact roads and bridges.
It is an issue Volvo Group Australia chief executive Martin Merrick says the company is working with authorities to investigate.
"There are some concerns about the impact on the infrastructure so we're working with the states, we're trialling vehicles with data-loggers and I'm confident we'll see their concerns satisfied," he said.
"We're also not going to go to 100 per cent of these vehicles overnight – this will take time."
Weight restrictions in Europe, he says, have been more generous, allowing up to 10 tonnes of weight on an electric trucks' front axle with no negative effects to date.
If laws to allow the vehicles are eased nationally and permanently, Mr Merrick says Volvo will manufacture large electric trucks at its facility in Wacol, Brisbane, in 2027, making the technology more widely available to local firms.
"The minute we get to that tipping point where the demand is there, customers want the vehicles and they're able to use them legally, we will start building here," he said.
"Without zero-emission vehicles, we will not get (to net-zero)."
