The assembly government has published its vision for the transport network in Wales over the next 25 years.
Car use is higher in Wales than for the UK as a whole, the plan says
The draft strategy calls for better use of the transport network, cutting the need to travel to work and encouraging more use of public transport.
It also sees road tolls as a potential way of reducing congestion, although not for at least the next 10 years and as part of a UK-wide toll network.
The draft strategy goes out for consultation until 14 October.
The assembly government says it recognises that Wales faces a major challenge over the coming years with the rise in demand for travel and increasing concerns about its environmental impact.
It points out that people in Wales travels on average more than 6,000 miles (9,656km) per year - a rise of 50% since 1980 - with a third of travel people going to and from work, and that car use in Wales is higher than in the rest of the UK.
Transport Minister Andrew Davies said he believed the assembly government should invest in "more sustainable and healthy forms of travel" and give people a "wider choice" of transport services.
MAIN STRATEGY THEMES
A more effective and efficient transport system through greater efficiency in terms of vehicle technology and existing network, plus investment in new infrastructure
Greater use of more sustainable travel - more car sharing, promoting walking and cycling and greater use of public transport,
Minimising the need to travel - for example by encouraging greater use of teleconferencing and home working
Strategy's main themes, from Connecting Wales, Welsh Assembly Government
And the minister told BBC Wales that congestion charging in Wales was "obviously a possibility".
Mr Davies said: "The experience in London, I think most people would say, has been very successful in decreasing congestion and clearly there may well be proposals coming forward from cities in Wales.
"I would expect that Cardiff may well want to consider that as part of an integrated transport system."
He said the money from such schemes would be invested back into improving transport.
The minister added: "The basic point is we cannot just carry on as we are. Traffic growth in Wales is growing faster than the rest of the UK."
The draft plan sets out a 25-year vision for transport which will try to encourage more people to work from home, to share cars and use healthier forms of travel such as cycling and walking.
Ministers also want the strategy to examine how to use modern technology to make working from home easier, so reducing people's need to travel.
The draft strategy proposes setting up four regional groups to draw up specific transport plans for their areas.
Sustainable transport, charity Sustrans, wants the assembly government to change its transport spending priorities away from roads in favour of public transport, cycling and walking.
Matt Price, Sustrans Cymru's national director for Wales, said: "We need a 'handbrake turn' on the way we travel in Wales."
Friends of the Earth Cymru called for more public transport and rail investment, while it said plans for the £400m M4 Gwent Levels toll motorway near Newport and the £50m A494 motorway link through Queensferry should be scrapped.
The environment group's transport spokesman Neil Crumpton said the transport policies which would be delivered over the next few years "will affect generations to come".
He added: "We must all make our next moves carefully and be cautious what we wish for."
Conservative transport spokesman Alun Cairns said: "Yet again, the Labour Party's only real answer to our transport problems appears to be a road pricing system which won't be introduced for years.
"It is time ministers realised that we need action now to improve transport in Wales, not vague ideas for the distant future".