A recent study has shown people are concerned about what's going to happen as income from the fuel excise diminishes.

Public support for a 'road tax' to replace the current fuel excise is growing, according to a new survey from EastLink.

The latest EastLink Self Driving Car Survey found 47 per cent of people think it's unfair for electric vehicles to use the roads without paying fuel tax to fund their maintenance, while a slight majority favoured replacing the current fuel excise with a 'road-use charge'.

Of the 18,000 people surveyed, 40 per cent agreed a road-use charge should be introduced to replace the current system, while 37 per cent opposed the idea. The remaining respondents didn't commit to either side, simply ticking 'don't know' on the survey.

Calls for a road-use charge, also dubbed the user-pays model or a congestion charge, has been backed by Infrastructure Australia on numerous occasions, but the proposal hasn't been properly discussed on any level of government.

"A reformed charging framework for roads would see all existing taxes and fees removed and replaced with direct charging that reflects each user’s own consumption of the network, including the location, time and distance of travel, and the individual characteristics of their vehicle such as weight and emissions," Infrastructure Australia said in a report released earlier this year.

Based on the 2018 Federal Budget, the fuel excise will earn the Federal Government $12.6 billion over the next fiscal year, up from $12.2 billion during 2017/18.

Forward estimates suggest the percentage of that money being pushed into 'land infrastructure' projects will be slashed from 61 per cent in 2017/18 to just 32 per cent in 2021/22.

As for what that tax would look like, 65 per cent of respondents to the EastLink survey said off-peak trips should cost less than on-peak journeys, while 51 per cent think it should be cheaper for electric vehicles to encourage uptake.

This support for electric vehicles ties in with the survey's findings on what people want to power their next vehicle. Respondents looking to buy a vehicle in five years time favoured electrified cars, with 40 per cent showing a preference for hybrid power and a further 32 per cent flagging interest in a pure-electric car.

Looking 10 years into the future, 38 per cent of those surveyed indicated a preference for electric power. Just 0.2 per cent of respondents currently own an electric vehicle, with petrol (80 per cent) the dominant fuel.