The RAC Foundation has welcomed the effect that the Budget is likely to have on driving in the UK, describing it as a "green light for cleaner motoring".
According to the group, British motorists will also welcome the fact that an increase in the price of fuel has been deferred owing to uncertainty about world prices.
Edmund King, executive director of the RAC Foundation, said that cars are gradually getting "cleaner and greener" and welcomed longer-term incentives for drivers to go green.
"Mr Brown’s radical proposal for tax disc reforms gives a green light to cleaner motoring. Drivers and manufacturers need time to change their vehicles," Mr King added.
"Reduced tax for cleaner vehicles is a great incentive to help motorists choose the most environmentally-friendly model suitable for their needs."
According to figures from the RAC, motorists pay £44.6 billion to the Treasury in motoring taxes every year, but only £7 billion of this is reinvested in the road network.