Route of all good

Which of these will save the world? Speed cameras on every road. A gauge on every dashboard showing real-time exhaust emissions. A market in which car makers buy and sell carbon quotas. These are suggestions from academics, specialists and policy pundits to help stop climate change. Can they be serious?

They certainly are. The policies have been selected by the Low Carbon Vehicle Partnership, from more than 30 submitted, as worthy of consideration. The UK government aims to reduce carbon dioxide emissions by 60 per cent by 2050 and road transport contributes around a quarter of CO2. So slash vehicle carbon emissions and our culpability for global warming will be similarly reduced.

But how can that be achieved? Routes that had seemed promising, such as road charging, hydrogen fuel cells and the promotion of new, cleaner technologies, have been diverted into lay-bys. Road charging might smooth the peaks and troughs in traffic flow but do little to reduce overall emissions. Besides, the abandonment last year of the planned trial to charge lorries is seen as a major setback to pay-per-mile projects. Progress now seems stalled until standards for road-charging systems are harmonised across Europe.

At the same time, the much-vaunted hydrogen economy is developing too slowly to help in the short term. The collaborative HyWays project of European researchers and industrial partners, including all the major car makers, estimated in March that the production of vehicles powered by hydrogen fuel cells won't even begin until 2013 and that by 2020 fewer than one per cent of all cars may be running on the gas.

And after the HyWays interim report was published, progress looked even bleaker domestically when transport minister Stephen Ladyman announced in June that the Department for Transport was abandoning several grant programmes planned to support the uptake of low-carbon vehicles. This was 'on the grounds that, if implemented, they would not achieve market transformation or provide value for money'.

At the time of going to press it was not clear what the DfT intends to do instead, but energy minister Malcolm Wicks told delegates at the LowCVP annual conference that the £40m will be refocused on, among other things, communications.

Wicks arrived at the conference in a hybrid Toyota Prius, a car for which motorists with a conscience are prepared to pay a premium and keep their carbon emissions down. By happy coincidence, the chairman of the LowCVP is Graham Smith, who is managing director of Toyota UK. Ever since the DTI and DfT funded the inception of the Partnership in 2003, Smith and the secretariat have attracted more than 200 stakeholders to join. It's a diverse group including car makers, component manufacturers, lobby groups, fuel producers, services companies, research organisations and academic institutions.

The energy minister acknowledged the Partnership's achievement in bringing them all together. 'LowCVP has been recognised internationally as a best-practice approach,' said Wicks. Later Smith tallied its successes. In the past year the Partnership pioneered colour-coded fuel economy labels for showroom cars, launched CENEX (The Engineer, 2 June) and supported development of the government's planned renewable transport fuels obligation (RTFO) which will require five per cent of all UK fuel sales to come from renewable sources by 2011. Yet in the years ahead, whether they are 1^oC warmer or even hotter, perhaps commentators will look back and regard the cocktail of policies suggested in its Low Carbon Road Transport Challenge as its most significant success.

The most radical was presented by Dr Jillian Annable on behalf of the UK Energy Research Council and the Slower Speeds Initiative. She said that by enforcing the 70mph speed limit on every trunk road, carbon emissions from vehicles will be cut by nearly one million tonnes a year.

Going further, by reducing the national speed limit to 60mph, emissions would be cut by 1.88 million tonnes each year. These savings, which are based on low projections of traffic growth, represent 15-29 per cent of the total expected from the transport sector by 2010.

'I am confident I have the perfect policy,' she said. 'Of all measures to manage the demand for travel by car, speed limits are simultaneously the mildest, the most straightforward, the least intrusive and the most egalitarian in their impacts.' She claimed the reductions in CO2 from speed enforcement compare favourably to the 1.6 million tonnes expected from the RTFO and, unlike the RTFO, the policy could be implemented quickly.

She pointed to other benefits. Longer journey times might reduce demand for road travel and this would lead to even greater reductions in emissions. Accident speeds would also fall, meaning over 300 deaths and serious injuries would be prevented each year on motorways alone, rising to more than 600 if the limit is lowered to 60mph. And she claimed lower top speeds and safety benefits would give the market for lighter and less powerful cars, increasing the carbon savings further.

There would, of course, be vocal opposition to this attempt to get the genie back in the bottle by cutting speeds and reducing the demand for ever-more powerful cars. But Annable and her colleagues are not daunted. '[It] would require less behavioural change than other measures,' she said. 'Alternative fuels, road user charging, car pooling, modal shift to public transport, more walking and cycling, high-occupancy vehicle lanes, tele-commuting would all either cost more or entail changes to travel behaviour that would be even less popular, more intrusive and harder to sustain or enforce. If the trade-offs are explained, drivers may prefer a lower speed limit to many other demand management interventions.'

Associate Prof Steve Cousins of Cranfield University and Axon Automotive has a different approach to cutting carbon emissions. He seeks to change driver behaviour by giving them real time information about the impacts of their driving style. He cites a dashboard gadget used in Finnish postal vehicles that helps workers alter their acceleration and braking patterns to boost fuel economy. The display shows coins dropping into a piggy bank when they are doing well. 'They claim a 15 per cent reduction in fuel use and a four per cent rise in productivity by smoother driving,' said Cousins.

He has suggested that similar displays could be retrofitted cheaply to all vehicles by MOT centres. They could show the amount of CO2 emitted, or saved. They could also be visible to passengers and alert them to aggressive, fuel-hungry driving styles. Cousins has calculated that carbon emissions would be reduced by up to 20 per cent. 'The big challenge now is to reverse the trend of power growth in new vehicles through appropriate policies. We should re-establish the manufacturers' agreement based on vehicle power categories,' he said. 'The new dashboard instruments proposed have great potential to encourage efficient driving, vehicle downsizing and trip optimisation.'

Imposing the onus of reducing carbon emissions on drivers was eschewed by Dr Robert Rabinowitz of the European Climate Exchange at the Low Carbon Vehicle Partnership conference. Instead, he favours the creation of a market in which vehicle makers can trade in carbon. Each will be set a limit to the amount of carbon the vehicles they manufacture in a year will be allowed to emit during their lifetimes. A manufacturer that exceeds its limit will have to buy carbon credits from those that have surplus. The cost of buying the credits will feed through to the price of the vehicles so motorists will be less inclined to buy models from manufacturers who don't play by the carbon rules.

That's the market-based theory and Rabinowitz claims it already works in other sectors that his company serves. To slow down or halt climate change he suggested that each manufacturer's carbon quotas be reduced each year, creating incentives for them to clean up their products.

Whether any of the above, or of the five other market-based solutions, regulatory approaches and tax-based prescriptions published in the Low Carbon Road Transport Challenge, are adopted as government policies has yet to be seen. However, Prof Mike Hulme, director of the Tyndall Centre for Climate Change Research, believes there is plenty of opportunity for policy alliances to be forged to reduce the transport sector's carbon emissions.

For his part Hulme told the conference that he, too, has a Toyota Prius. He also revealed how difficult it can be to change motorists' behaviour, no matter how well-informed they are of the impact of their vehicles, by admitting he had been banned from driving for six months after being caught speeding. That is clearly one route to reducing road vehicle emissions at a stroke but is most unlikely to ever become government policy.