The proposals were among eight winning entries to the Low Carbon Road Transport Challenge, a competition run by the Low Carbon Vehicle Partnership.
The challenge was intended to encourage academics, think tanks and various other non-governmental organisations to suggest future policies that could encourage the take-up of greener cars and progress towards carbon reduction targets.
Four of the winning entries were presented at the LowCVP’s annual conference in London last week.
Dr Jillian Anable, from the UK Energy Research Centre, said cutting the national speed limit to 60mph and enforcing it more rigorously would reduce fuel usage and therefore emissions, as well as improving safety, reducing accidents and improving traffic flow.
Alex Veitch, who works for the Energy Saving Trust but submitted his proposal independently, investigated options for carbon regulation of the European car industry, advocating a company-specific CO2 target, reduced annually.
Dr Robert Rabinowitz, of ECX Associate Membership, helped set up the Chicago Climate Exchange and proposed a similar carbon emission trading scheme in Europe.
He says it would provide a financial incentive for vehicle manufacturers to beat their reduction targets.
Dr Ben Lane, of the Open University, proposed a new pay-as-you-drive taxation scheme based on vehicle emissions, scaled in the style of the fuel-efficiency labels found on new cars.
LowCVP director Greg Archer said: ‘We need urgently to fully evaluate these and other policy proposals and initiative to tackle rising road transport CO2 emissions.’