Charging road users could help fund improvements to public transport, a key report from the Scottish Government’s Just Transition Commission has warned.

SNP ministers have pledged to reduce car kilometers by 20% by 2030 a key component of a legally-binding commitment to reduce carbon emissions by 75%, compared to 1990 levels.

Almost one third of Scotland’s emissions come from transport.Congestion charging, similar to that in London, is one method that has been talked about to halt the number of cars driving into Scotland’s cities.

In June, The Herald revealed that the leader of Edinburgh City Council, Cammy Day, was not ruling out reviving plans for a congestion charge for the capital but stressed the idea was “not on the table presently”.

Read more: Glasgow LEZ could be followed by congestion charge

The idea was brought forward by SNP councillors in Edinburgh, before losing control of the city at the last council elections.

Last week, The Herald also exclusively revealed plans to charge commuters driving into Glasgow by council chiefs.

Now, a new report from the Scottish Government’s Just Transition Commission has suggested that if measures such as charges to road users were introduced, those funds should go into improving public transport.

The document adds that “rail, bus and ferry services need urgent improvements”.

The report has warned that tough decisions and behaviour changes required of the public will need to be clearly communicated.

It said: “A long-term public information campaign will be needed to build collective understanding of what action is being taken, how full compliance is being achieved, progress reporting, challenges and positive impacts.”

Read more: Edinburgh Council leader vows to learn from Glasgow's LEZ 'mistakes'

The independent expert advisory group advises the Scottish Government on how the country can achieve a carbon-neutral economy in a fair way.

Last month, the commission’s chairman and Dundonian climate scientist, Professor Jim Skea, was elected to lead the Intergovernmental Panel on Climate Change, the high-profile United Nations body whose reports have played a key role in shaping global understanding of the climate emergency over the past 30 years.

Today he announced he has resigned from his role as chairman of the Just Transition Commission, with a successor to be announced in the coming weeks.

Professor Skea said that despite him stepping down, it was “time to push ahead with bold action to make just transition a reality”.

He said that “internationally, people are looking at Scotland as a leader on just transition”, adding that “now we must strive to justify that position”.

Read more: Nicola Sturgeon open to councils charging drivers for roads despite 'triple-whammy' criticism

He added: “Our current transport system is far from just, and for many people it is already simply too difficult or expensive to get around.

“Building and maintaining trust and understanding around these kinds of changes will be key.

“People need to have faith that everyone is paying their fair share and that the benefits outweigh the costs. The climate crisis means every country in the world is going to face up to tough questions like this sooner or later.

“The good news is Scotland’s commitment to a just transition means we are well-placed to confront these issues together right now.”

Professor Jillian Anable, a member of the commission and transport expert at Leeds University, said: “The transition to a decarbonised transport system in Scotland requires rapid and wholescale changes to the vehicles we use as well as how much we use them.

“The Scottish Government have set a target to reduce the proportion of car miles travelled by 20% by 2030.

"This is a great opportunity to address some current inequalities whereby some people have to rely on inadequate and expensive public transport, others are forced to spend money on car travel that they struggle to afford, and others travel very high mileages, often in increasingly large cars.

“A just transition would involve redirecting resources into the supply of better public transport, walking and cycling facilities and planning housing and other facilities that are well connected by this infrastructure”.

Lang Banks, a commissioner and director of WWF Scotland, added: “If Scotland successfully delivers a just transition it will have helped contribute to a fairer society at the same time as addressing the climate and nature crises.

“However, to deliver a transition to net zero that is fair for workers, communities, and consumers it’s crucial for decision-makers to go meet and listen to those who might be directly affected, as we have done.

“Specifically seeking out and hearing from those whose voices are often not heard will help ensure that the benefits as well as the burdens of the changes required are shared more equitably.”

A Transport Scotland spokesperson said: “The most direct levers on the cost of buying or running a petrol or diesel car – fuel duty and vehicle excise duty – are reserved to Westminster.

“The Scottish Government is committed to making sustainable travel a more attractive option, which is why we invest over £2 billion annually to support public transport - providing up to 2.3m people in Scotland with access to free bus travel. We will work with all local authorities to support equitable measures which encourage active travel and accompany greater investment in public transport for a fairer and greener transport system.

“The draft route map sets out how we will reduce car kilometres by 20% by 2030 - a commitment which demonstrates our level of ambition in meeting Scotland’s statutory targets.

“As outlined in our route map, the scale of the challenge means that we need to take forward a broad combination of interventions, including infrastructure, incentives and regulatory actions.

"However, we are committed to a Just Transition, and therefore agree with the Commission that approach must take into account the needs of those who may be less able to reduce car use, such as carers and those living with a disability, or in  rural locations.”