Joint research by the Slower Speeds Initiative and the UK Energy Research Centre concluded that a 60mph speed limit would significantly reduce carbon emissions in an equitable and cost-effective way. This measure, which could be introduced now, would help to curb traffic growth, the most intractable problem in getting carbon emissions from surface transport under control. It would also contribute more than the reduction expected from the Renewable Transport Fuels Obligation.

You can download the report from:

http://www.slower-speeds.org.uk

or: http://www.lowcvp.org.uk