Speed limit rise would increase deaths and pollution, admits government - The Guardian

The government has admitted that its proposal to increase the speed limit on motorways to 80mph would lead to more pollution and increase the risk of road deaths. Transport officials also told the Guardian that there would be no widespread roll out of 20mph limits in towns – a measure that is reportedly a concession to the Conservative's Lib Dem coalition partners.

Transport secretary Philip Hammond said the existing 70mph limit was "out of date", and that Britain needed to be "back in the fast lane of global economies". But the Department of Transport said that no impact assessment has been made of the proposed speed increase, only an "initial analysis".

That analysis indicated a 1% increase in all road deaths, meaning 19 more fatalities based on the 1,850 people killed in 2010, or 25 more fatalities based on the average of the past five years. The department could not provide an estimate of the increase expected in the 209,000 road injuries seen in 2010.

"Cars are much safer than in 1965, when the 70mph limit was introduced," said a DfT spokeswoman. "Traffic accident casualties have fallen by 75% since then. Setting the right limit means balancing all the effects. We are asking if the balance is still correct."

However, Ben Stewart of Greenpeace sais: "The more we learn about the new speeding rules, the worse it looks. This was meant to be the decade we finally made the big push to get off oil, instead we have a government driving hell for leather in the wrong direction."

The DfT's initial analysis of the pollution increase resulting from an 80mph limit is 670,000 tonnes CO2/year, described as "modest" by officials, as it represents 1% of the total emissions from cars, small vans and motorbikes on all UK roads.

But the figure is challenged by analysis from the government's official climate change advisers. The analysis published by the Climate Change Committee in a report to parliament in June 2011 showed the proposed increase could add emissions of up to 2.2m tonnes CO2/year, more than three times higher.

A CCC spokeswoman said: "Based on this analysis, and the need for deep emissions cuts over the next decade to meet legally binding carbon budgets, the CCC recommended that the aim should be to enforce the existing limit, rather than increase it."

Jillian Anable, a transport expert at the University of Aberdeen, said disagreement over important figures used by the DfT's models could explain differences. The DfT used data on the efficiency of cars at high speeds taken from "a very, very small study that has not been peer reviewed or verified", she said. Anable's own modelling indicated the rise to 80mph would cause a rise in emissions of 910,000 tonnes, 35% bigger than the DfT estimate. Sian Berry, from the Campaign for Better Transport, agreed the DfT underestimated the impact: "In practice, real fuel consumption will increase much faster than the DfT traffic models predict, so carbon emissions will be higher."

Anable said the rise in emissions should not be considered modest. "The transport sector does not have many big levers to pull in cutting emissions," she said. "Compared to other options, speed limit changes are very significant. We have finally seen a fall in transport emissions in recent years; a speed increase could directly counter that."

"When we do the consultation, we will publish an impact assessment," said the DfT spokeswoman, adding: "We have no plans to change the current arrangements regarding 20mph zones. Local authorities have the power to do that and it's right that they should do so."

Stewart said: "The DfT's number-crunchers appear to have misplaced 1.5m tonnes of CO2, while the increase in 20mph urban zones looks less a serious initiative than a public relations fig leaf for the Lib Dems."

Previous research has shown that a medium-sized petrol car increases its emissions by 15% when going from 70mph to 80mph, while diesel cars with engines of more than two litres increase their emissions by 25%.

Other work on the link between speed increases and deaths on those roads showed a 38% increase in death for a 10mph increase on US roads and that German autobahns, which have no speed limit, have a death rate 75% higher than that in the UK.

Other concerns raised include a fear that increasing the speed limit will actually slow journeys, and fail to deliver the £100m a year economic benefit Hammond has cited. "Numerous studies have shown that, at higher speeds, traffic flow becomes more unstable," said Berry. "Recent experience with the Highways Agency's managed motorway programme also backs this up – when traffic congestion builds up, cutting the speed limit to 50 or 60mph means everyone drives more steadily, and this helps to prevent jams and save time for everyone."

Support for the idea has been muted, though a poll for the Institute of Advanced Motoring in May suggested 70% of drivers would back the increase. But Stephen Glaister, director of the RAC Foundation, was in two minds: "There are good reasons for making 80 the new 70, and good reasons not to. Drivers travelling that 10mph quicker might reach their destination sooner but will use about 20% more fuel and emit 20% more CO2."

The UK's highest profile petrolhead, Jeremy Clarkson, backed the speed increase on Friday: "An 80mph limit is good for the economy, polar bears and your soul," he wrote in the Sun. "It is also good for parents who will get home quicker to stop their children becoming glue sniffers. The limit should be 180mph." His support is a reversal of previous statements, as he wrote in 2002: "It is not fine to have an 80 limit in Britain because then, the police will turn a blind eye to those doing 95. And 95 on British motorways is too fast."