Its chairman, Sir John Houghton, said: 'We must start now, of course.'
Although the Government is expected to take months before it formally responds to such a challenging report, he hoped Kenneth Clarke, the Chancellor, would take one of its key recommendations on board for the Budget later this year.
The Government is already committed to raising road fuel prices by 5 per cent above the rate of inflation each year for the rest of the century - implying a 13p a gallon rise next April. The commission wants this put up to 9 per cent, 6p more.
The real cost of petrol, measured against the cost of other goods, is currently close to its average since the early 1950s when mass motoring got under way. The commission's objective is to see its real cost go far above the oil-shock peaks of the mid-1970s and early 1980s, to a level where it acts as a serious disincentive to private motoring.
The Automobile Association's public policy manager, Bert Morris, said: 'Yet again we are faced with penalties to drive us out of our cars on to non-existent or inadequate alternatives.'
He warned the Government and opposition parties that opinion-polling for the AA had found that 55 per cent of drivers 'would vote against politicians who try to price them off the road'. The RAC called the proposal 'socially divisive and regressive'.
But the commission argues that such a rapid increase in road fuel taxation is needed to preserve the environment and public health. 'We consider this present transport system is not sustainable, because it imposes environmental costs which are so great as to compromise the choices and the freedom of future generations,' the report says. Today's generation had to shoulder the task of righting the wrongs of the present and the past.
If there were not radical changes in transport policy, travel of all kinds would continue to grow by 20 per cent a decade, along with worsening air pollution, noise nuisance and damage to communities, landscapes and wildlife. The commission wants to slow this growth rate to 10 per cent, but keep road traffic levels in 2020 at roughly the present level.
The extra tax revenues from higher fuel duty would come to pounds 6.5bn a year by 2000, says the report. 'This additional revenue would comfortably exceed the additional requirements for public expenditure identified in this report.' It urges greater government investment and subsidies for public transport and off-road freight.
Near the end of the report there is recognition that the tax increase will impose a heavy burden on car-dependent people - especially those on low incomes - who live in rural and suburban areas ill-served by public transport. But the report points out that the poorest families are dependent on public transport and rejects subsidies or tax breaks for low income or rural car owners, favouring subsidies to improve public transport instead.
Yesterday, all but one of the 11 commissioners attending the report's launch in Westminster, central London, said they had used public transport, bicycles and foot to travel to Church House. Only Lord Selbourne confessed to driving. But Richard Macrory, a lawyer and academic, pointed out that all the commissioners were regular car users. What they wanted was real choices in transport so they could use their cars less.
The commission wants the remaining incentives for company car mileage, heavily curbed in recent budgets, to be eradicated. It calls for a Department of Transport propaganda campaign to encourage safer, less aggressive driving which would also cut pollution.
One of its more challenging recommendations is for the average new car by 2005 to be 40 per cent more fuel-efficient with less stringent targets for vans, lorries and buses.
The technology needed to meet the commission's demands for cleaner exhaust emissions and improved fuel efficiency in the next 10 years already exists.
What is lacking, say motor industry experts, is the right mixture of legislation, incentives, penalties and 'image' required to bring them into mass production.
Clean diesel cars, second- generation catalytic converters, and even the more exotic hybrid electric and gas-turbine engines are all here or only a few years away. Neil Marshall, policy director of the Retail Motor Industry Federation, said the increasing use of electronic intelligence in engine management systems over the next few years would improve efficiency, with computers making thousands of checks on performance every second.
18th Report of the Royal Commission on Environmental Pollution, Transport and the Environment; HMSO; pounds 25.60.