A MOTORING group has attempted to explode the "myths" of road-building, a move which has triggered scorn from environmentalists.
The report by the RAC Foundation claims new roads do not significantly increase emissions or simply fill up with traffic after being opened, and that traffic pollution is not getting worse.
The study is seen as an attempt to prevent roadbuilding from falling victim to government spending cuts.
Stephen Glaister, the foundation's director, said: "Road building, if well designed, can be a cost-effective way of improving mobility for all, without having a material effect on climate change."
However, the Green MSP Patrick Harvie dismissed the claims as "the thinnest set of pseudo-scientific arguments for unsustainable road-building that could be imagined".
He said the foundation complained that motorists were paying too much, yet it admitted its arguments depended on the introduction of road tolls.
Duncan McLaren, the chief executive of Friends of the Earth Scotland, said: "Far from 'myth busting', the claims in this report comprise a litany of misleading assertions, half truths and straw men. I don't think I've seen such a dodgy dossier since the one used to justify war on Iraq."
The foundation, formerly the research arm of the RAC, said it "campaigns to secure a fair deal for responsible road users".
It is thought to fear that ministers may include new roads in any spending cuts forced by the looming recession, since that could help them meet climate change reduction targets.
The foundation's claims also come despite the Scottish Government admitting that planned new major roads will increase carbon dioxide emissions by more than 250,000 tonnes a year by 2025.
More than half of the extra emissions would be produced by the five-mile M74 extension under construction in Glasgow, which is currently expected to cost 692 million – or 26,000 a foot.
Two sides to every story on the future of transport
1 RAC FOUNDATION: New road capacity does not simply fill up with traffic. Additional traffic may occur on new routes as less suitable roads are relieved of congestion.
GREEN PARTY: New road capacity has been shown to generate an average of one-fifth more traffic, greatly increasing climate-changing emissions. New roads lead to new journeys being taken on them.
2 RAC: Building roads will not have a significant effect on climate change, so long as wider policy measures are also introduced. Road building on its own can slightly increase carbon dioxide emissions, but it could also reduce emissions by up to 10 per cent if introduced alongside road-pricing.
GREEN: Relying on the car and pricing public transport out of the market is exactly what underlies our current worsening emissions. Of the 19 road-building projects currently planned by the Scottish Government, just one shows any carbon reduction.
3 RAC: Traffic pollution is not getting worse. Vehicle technology has reduced traffic pollution significantly.
GREEN: The most recent figures show that in 2004-5, Scotland's road transport emissions of increased by 70,000 tonnes.
4 RAC: Roads do not occupy large areas of land – they cover less than 2 per cent of the surface of Britain.
GREEN: Land for roads, such as the proposed Aberdeen bypass, is often the most beautiful and ecologically sensitive.
5 RAC: The UK is not unusual in Europe in relying on roads and has the lowest level of motorways and main roads relative to its population.
GREEN: This is spurious and ignores so many other factors, notably the higher costs of public transport in the UK.
6 RAC: Building roads will benefit low-income groups, as all income groups rely on roads for more than 92 per cent of their travel.
GREEN: Most of the poorest in society live in households without access to a car. Britain has historically had the lowest investment in public transport, leading to its excessive cost and limited services.
7 RAC: The construction industry can accommodate a substantial increase in road building.
GREEN: The construction industry would no doubt deliver any level of road-building required.
8 RAC: Roads are efficient users of space in comparison with the railways. Roads carry almost five times more passenger traffic than railways and take up only 50 per cent more land.
GREEN: Roads are more heavily used because the total cost of motoring continues to fall, despite changes to oil prices. Driving generates about three times as much per passenger mile as trains.
9 RAC: Public transport is not a ready alternative to the private car. Railways serve very distinct markets and have little room for additional passengers. Bus services cover less than 23 per cent of the road network.
GREEN: In a compact country like Britain, high-quality public transport is easily deliverable, if there (is] the political will.
10 RAC: Road traffic does pay its way. Even if road users were put in a unique position of needing to pay all of their external costs, such as pollution, congestion and for accidents, current charges are too high.
GREEN: When the effects of pollution are factored in, as they should be, these taxes cover less than half of the overall costs imposed on society.
11 RAC: Building new roads is not too costly. In many cases, the benefits of road development have vastly outweighed its costs.
GREEN: The costs of developing new roads are enormous. The Scottish Government is about to spend 6 billion on unnecessary roads.