Traffic planners can do much more to speed traffic flow and reduce CO2 emissions.

Reducing queues at traffic lights could make a massive difference to greenhouse gas emissions from cars. The Automobile Association says that if local councils re-set lights to reduce waiting times by just a minute on three major roads could mean 645 fewer tonnes of CO2 reaching the atmosphere.

The AA’s president, Edmund King, said many councils try to restrict car use, but they should also look at ways to keep traffic moving. ‘Councils should be accountable for CO2 reduction by upgrading gridlocked junctions, co-ordinating road works and reducing waiting times at traffic lights,’ he said.

‘They need to be measured on traffic efficiency. If residents agree to environmental taxes or having their street lights turned off, the money generated should be spent on improving roads, rather than propping up town hall finances.’

At present, some councils have introduced policies intended to push residents to buy smaller, greener cars or even do without them. The London borough of Richmond charges owners of big off-roaders and other cars that emit over 226g/km of CO2. The ‘greenest’ cars, such as Volkswagen’s Polo Bluemotion, park for free. The local authority for Norwich prices permits according to the length of your car, while Buckinghamshire county council is turning off street lights at night to save energy.

While the Highways Agency, which looks after motorways and other key roads, is working to cut queues, few local councils are doing their bit. But the AA says there are ‘massive benefits’ to be gained by keeping traffic moving. If Buckinghamshire, for example, re-worked traffic light phasing to cut queues on three busy roads, it would reduce CO2 by more than it will by turning off 2000 street lights.

Drivers can help cut CO2 emissions, by turning their cars off whenever stopped for longer than 30sec. They can also buy cars which turn themselves off and restart easily. These include hybrid cars (with petrol and electric engines) such as the Honda Civic saloon, the Toyota Prius and the Lexus GS 450h. Latest Minis also turn themselves off whenever the handbrake is applied and the gears slipped to ‘neutral’, restarting as soon as the clutch is dipped and a gear selected. Citrn offers its Stop and Start system on its C2 city car and C3 supermini. This stops the engine when the car is at a halt, re-starting as soon as the foot brake is released.