Ministers plan to test a vehicle scrappage scheme, which comes as they seek to both cut emissions and meet an ambitious target of reducing traffic by 20 per cent by 2030.
It could build on a scheme offering low-income households up to £3,000 to scrap older vehicles whose engines do not comply with new low emission zones (LEZ) in Scotland’s four biggest cites.
No details of the latest plans are yet available, but the LEZ initiative includes up to £1,000 per household towards alternative travel, such as buying a bike or cycle hire scheme membership, multi-trip bus and rail tickets, and membership of a car-sharing club.
The Scottish Government’s 2022/23 Programme for Government, published on Tuesday, pledged it would "test a new mobility and scrappage scheme to help low income households to replace a polluting vehicle with the means to travel sustainably".
The news was welcomed by environmental campaigners, but with scepticism from motoring groups.
Gavin Thomson, transport campaigner at Friends of the Earth Scotland, said: “Transport is our biggest source of climate emissions and cars are the biggest chunk of that, so tackling the climate crisis has to mean reducing car use.
"Around Europe, we have seen successful scrappage schemes that replace people’s old, polluting cars with free public transport or credits that can be used to buy other household items.
“People on the lowest incomes mainly walk or use the bus, but for families that have a car and are struggling to make ends meet, a scheme like this could make a big difference.”
Colin Howden, director of sustainable transport campaigners Transform Scotland, said: “Now would be a good time to refocus scrappage grants around bike purchases, public transport season tickets, and memberships of car clubs.
"This would be a more complete sustainable transport response than providing grants for one car to be replaced by another, however low emission the new car might be."
But Neil Greig, policy and research director of IAM RoadSmart, doubted the scheme would work across Scotland and called instead for support to cut rural fuel prices to be increased and extended.
He said: “A new scheme linked to cheaper bus fares or free bikes might have some attraction in larger urban areas where viable alternatives exist, but once you get outside the city it would have very limited appeal as an incentive to get rid of a car.
"There is little point in giving someone a free bus pass if there are no services to get them to work early in the morning or late at night.
"Giving people a bike when we still don’t have enough segregated infrastructure to make them feel safe when using it is also likely to have little impact.”
Steve Gooding, director of the RAC Foundation, said: “In theory, scrappage could be part of the solution, but we shouldn’t underestimate how tricky it is to design a scheme that carefully targets those vehicles which are not only old, but also rack up the most miles in Scottish towns and cities.
“Get that wrong and the costs could balloon out of all proportion to the actual air quality improvements delivered.”