Reducing CO2 from cars

Simple measures may be smarter AA President argues

9 September 2009

Better evaluation of the CO2 impact of road schemes and smarter use of simple measures may cut greenhouse gases more quickly than grandiose projects, such as congestion charging that take years and millions of pounds to implement, says the AA's President, Edmund King. On Wednesday, he will be discussing urban mobility at the Westminster Energy, Environment and Transport Forum in London and will warn that excessive traffic calming can backfire.

Two examples stand out. Firstly, the rolling out of 20mph speed zones across the country without a proper assessment of their impact on CO2. Secondly, the poor implementation of park and ride schemes – leading to some being scrapped – even though they can reduce CO2 and congestion significantly.

Putting CO2 savings in perspective, government figures show that by far the greatest contributor will be car technology1, saving more than five million tonnes of carbon by 2020. Better car fuel-efficiency is one of the main reasons that UK passenger cars produce less CO2 than they did 10 years ago, and with a third more now on the country's roads.

In comparison, savings from a fuel duty escalator would contribute less than two million tonnes in CO2 reductions while measures to force drivers on to public transport would contribute barely one million tonnes in CO2 reductions. King also argues that the high cost of fuel removes the need for a duty escalator.

Although supportive of targeted 20 mph limits on urban residential streets for safety reasons, the AA is concerned that the blanket roll-out across the UK is being done without assessment of the additional CO2 impact.

Twenty mile per hour speed limits on inappropriate roads can pump up CO2 emissions 10%, a concern raised by the then Department of Environment, Transport and Regions in 2000. Without proper research, council engineers have no data or guidance for planning 20 mph speed limits that don't unnecessarily aggravate CO2 emissions.

Accepting that it can be difficult to persuade drivers to change their routines, the AA is nonetheless disturbed to see the closure of park and ride facilities, notably in Brighton. Former park and ride users have been diverted on to local buses at a return cost of £3.60 per person when the cost of parking in the council's city centre multi-storey is £3.80 for six hours. In Portsmouth, a similarly congested tourist city, park and ride costs £2.50 per car.

The AA believes that simple signs on main roads, showing the comparative costs for using a park and ride scheme as opposed to town centre car parks, could be effective in persuading greater use of CO2-efficient parking on the outskirts. It also argues that the priority use of extra income from car parks is to keep park and ride facilities open, not to prop up council finances.


Commenting, Edmund King, AA President, said: "If we are smart about urban transport we can reduce CO2 and congestion without spending millions. Congestion and CO2 can be reduced by improving traffic flow through co-ordination of road works, phasing of lights and good parking policy. If we continually obstruct traffic with excessive traffic calming, we will increase congestion and CO2. New technology to improve fuel efficiency will be the biggest contribution to reducing CO2 from road transport."

In his presentation, the AA's President also lists other ways to reduce congestion and emissions without resorting to congestion charging which was rejected by 67% of AA members in an AA Populus poll.

These include:

better organisation of streetworks
more efficient phasing of traffic lights
alleviating traffic pinch points
encouraging cycling
routing buses to suit better the travel patterns of potential users, and
parking policies, such as red routes.


Edmund King will be addressing the Westminster Energy, Environment & Transport Forum seminar on Urban Mobility on 9 September in Central London.

1CO2 reduction figures based on Climate Change Programme/Energy White Paper in a report from the Commission for Integrated Transport which E King helped compile.

Join the discussion in the AA zone


9 September 2009