Average-speed cameras could be installed on all motorways to help slash the UK's CO2 emissions, according to the Government-backed Sustainable Development Commission (SDC).
SDC research has also shown that 52% of drivers ignore the 70mph limit.
Cut speeding to slash emissions, says commission
The SDC has called for the introduction of average-speed cameras on all motorways to help cut speeding, which it claims will reduce harmful CO2 emissions by 1.4 million tonnes a year.
Average-speed cameras are considered more effective at cutting speeding because they measure speed over an extended distance, rather than at a static point.
Traditional Gatso-type cameras have been accused of increasing pollution because they cause drivers to brake suddenly and then accelerate hard once past the device.
Introducing such cameras on motorways and urban roads would help encourage smoother, more economical driving, according to the SDS.
More average-speed cameras on the way
Government ministers are also expected to approve the use of average-speed cameras on networks of urban roads where a 20mph speed limit is in force.
London Mayor Boris Johnson has also said that he intends to introduce average-speed cameras on a 7.5-mile stretch of the A13 in London.
Other recommendations from the SDC's report include:
• All cars to be fitted with speed limiters to cut CO2 emissions;
• Calls to set a timetable for the introduction of technology to make it impossible for drivers to exceed local speed limits;
• The promotion of teaching motorists how to drive in an environmentally friendly and fuel-efficient manner;
• Calls for the introduction of pay-as-you-drive road charging.
Stewart Davies, from the SDS, said: 'While information technology alone won't provide all the answers, it could go a long way towards making travel in the UK safer, more pleasant and more sustainable.
'Already, eco-driving technology can help motorists spend less at the pumps and reduce their emissions; better information can make using public transport easier, and video conferencing technology can help business travellers avoid some journeys altogether'