The success of John Prescott's White Paper will depend in great part on political will at local and national levels. Much will also depend on the common sense of politicians and engineers.
It will be ten years or more before the impact of this week's Transport White Paper can really be assessed. Only then will it be possible to judge the results of the anticipated growth in bus lanes, light rail schemes, road pricing and green commuter plans.
All the White Paper can really do is provide the tools for national and local government to make an integrated transport policy work. How these are used will determine the success of the UK's first attempt to introduce an integrated transport strategy in decades .
Much will depend on political will at national and local government level. Transport consultant MVA's deputy managing director Denvil Coombe says that local authorities will need to bite the bullet and act if they are to shift traffic off the roads and onto other transport modes.
Coombe points out that local councils turned down the offer to introduce road pricing from Brian Mawhinney when he was one of the Conservatives' succession of Transport Secretaries.
Mawhinney told them that if they wanted to introduce it, he would deliver the necessary legislation. The offer was never taken up. Instead, councils took the softer option of tightening up on non-residential parking - a policy which Coombe says is largely ineffective. He feels that people who drive to work tend to seek alternative on-street parking, or use local car parks, rather than use public transport.
Radical measures like road pricing, or even less radical ones like extending priority bus or cycle networks, will also need co-ordination between neighbouring authorities if they are to prise motorists out of their cars.
If one town starts applying anti-motorist measures such as road pricing or bus prioritisation, there might be a temptation for businesses to relocate. Shoppers could also switch to a more car-friendly neighbouring conurbation.
Pressure group Transport 2000 has long advocated a national integrated transport policy. It remains optimistic about the prospects for co-ordination, pointing out that central government has already begun to encourage the co-ordination of local transport plans.
Under this initiative, central government transport funding bids by local authorities are assessed in relation to plans set out by their neighbours. The set-up allows central government to withhold money from projects developed in isolation.
Councils are also being encouraged to bid for money to fund packages of schemes, rather than for large individual projects, under an approach developed by the Conservatives in the early 1990s. Bids are assessed according to targets for reducing road accidents, congestion or pollution.
Positive signs that the government is prepared to spend more on local transport schemes also emerged from the Treasury last week. 'We were heartened by last week's Comprehensive Spending Review,' says Friends of the Earth transport campaigner Tony Bosworth. The CSR quadrupled cash available for local authority transport funding packages from £85M a year to £360M.
Lack of money has always been a major obstacle for local transport schemes. This new money should unlock many projects. 'There are a lot of good packages out there, and lack of funding is the only thing stopping them,' says Bosworth.
But more money for public transport, whether from central government or, eventually, from road pricing, is not the whole solution, according to MVA's Coombe. 'Just improving public transport will not entice drivers out of their cars,' he says.
In towns and cities, trams and light rail schemes have always been seductive transport alternatives - especially for local politicians. But opinion on their usefulness is divided. FoE cites Manchester's Metrolink as a success, claiming that it has reduced road use. Others, like MVA's Coombe, are more sceptical about the size of the shift.
Coombe does accept Manchester Metro has done a better job at getting people out of their cars than the Sheffield Supertram. This is because Sheffield's trams, unlike Manchester's, share street space with road vehicles and get caught in traffic jams as a result.
Coombe says that cities like Zurich have also invested heavily in public transport, but the improvements have only succeeded in curbing traffic growth rather than reducing vehicle use.
For him, investment has to make public transport much quicker, and be accompanied by city centre vehicle bans and road pricing if enough people are to make the switch and the investment worthwhile.
But even if local authorities do introduce road pricing, they will not find it easy to implement. In large cities like London, it will be difficult to impose schemes that are too localised without the risk of causing congestion in neighbouring areas.
This was one of the main objections voiced by London authorities to the City of London's recent proposal to charge motorists entering the ring of steel - the area of restricted entry set up following a series of terrorist attacks in the Square Mile (NCE 9 July). Tests in smaller cities like Edinburgh look more likely as a first step (see box).
In London, Coombe advocates a much wider road pricing area. 'To be effective, a congestion charging system has to cover not just the city centre, but the whole urban area,' he says. Coombe estimates that imposing road pricing over a large area of central London would involve 13M transactions per day.
Cars and lorries will still have an important role to play as inter- urban transport modes, even if integrated transport means pricing or banning them from city centres. Coombe believes that there is still no acceptable substitute to road transport for manufacturers and retailers who rely on just-in-time delivery.
This goes for Britain as much as for countries like Germany, with supposedly more integrated transport systems. German autobahns are still full of lorries, although the rail network is more sophisticated than Britain's.
Coombe believes that money will still have to be spent on new roads, despite the current anti-roads climate. 'The argument goes that for the economy to grow, we need good road systems. Growth requires more traffic,' he says.
Constraining motorway growth by tolling, electronic or otherwise, could be damaging, he adds. Motorists, especially on short journeys, will divert to local toll-free local roads instead of switching to alternative transport modes, shifting rather than solving the congestion problem.
Progress towards an integrated transport policy is not expected to be quick, but if Labour is still in power after the next election, a failure on transport could well come back to haunt it. 'The test will be - is it going to bring about a real reduction in traffic levels,' says FoE's Bosworth. For him this would be nothing less than a 10% drop in road traffic levels by 2010.