Scottish ministers should back up plans for 20mph speed limits on urban roads with a £2.5 million advertising campaign aimed at creating “culture change” for drivers, say experts.

The idea – which would try to make speeding as unacceptable as drink driving – has been backed by the Scottish Green MSP, Mark Ruskell. He is introducing a “safer streets bill” to make 20mph instead of 30mph the default speed limit in built-up areas. But there are concerns that some motorists may ignore new limits.

Ruskell commissioned Alan Tapp and Adrian Davis, marketing and transport specialists from the University of the West of England, to investigate how to ensure drivers keep to 20mph. They are due to present their findings at a meeting in the Scottish Parliament tomorrow.

Tapp and Davies argue that the Scottish Government should budget £2.5m for adverts, allied with police enforcement. The aim should be “a zero-tolerance policy towards speeding in residential areas and busy high-streets”, they say.

“We want to make speeding in 20mph limit areas socially unacceptable on the grounds that speeding has created a hostile environment, preventing residents from living what should be a normal, civilised life where they and their children can venture out without anxiety.”

Tapp and Davis want to challenge the culture in which speeding on residential roads is seen as normal. “We are reawakening people to what we hope they would then come to see as a daily insanity of cars dominating how they live their lives,” they add.

Tapp, a professor of social marketing, pointed out that although 20mph limits had majority support, some drivers tended to breach them. “Regular bursts of communications across a wide variety of channels are needed to get the message across about the best ways to behave on the roads,” he said. "This kind of marketing, effective though it is, still needs support from other activities, in particular local engagement with communities, and of course appropriate police enforcement. The idea is that all these activities work in harmony so that drivers will slow down on residential roads.”

The Scottish Greens argued that £2.5m was a small amount to pay compared to the £800m a year spent on roads. The adoption of a 20mph limit in Bristol had saved the city £15m, with four fewer deaths and 170 fewer injuries, they said.

According to Ruskell, there was a “small minority” who opposed 20mph limits. “A public awareness campaign would ensure speeding remains a socially unacceptable behaviour,” he said.

“While it's right to say that a price cannot be put on public safety, it's important we understand that for a minuscule cost we could have safer streets in our communities.”

Stuart Hay, the director of the campaign group Living Streets Scotland, backed 20mph as the default speed limit in built-up areas. “Through a mix of advertising, enforcement and engineering we can create a change in culture, reducing the speeds people drive and creating safer streets for everyone to walk and enjoy,” he said.

The Scottish Government argued that local councils were responsible for speed limits. “Given the varied nature of Scotland's urban road network and the number of factors which need considered when setting appropriate limits, we believe decisions on 20mph speed limits are best taken at local authority level,” said a Transport Scotland spokesman.

“However, as Transport Minister Humza Yousaf has said all along, we'll keep an open mind on Mark Ruskell's bill. We look forward to seeing the detail of any legislative proposals which are put to parliament.”