The debate about road pricing centres on the assumption things like "wish lists" to force school run drivers off the road, could reduce congestion.

However, current research and the Government's own figures show a more complex picture.

A study by the Institute for Public Policy Research last year found road pricing would increase road traffic and cause more exhaust emissions.

The Government's feasibility study also found there could be more accidents as motorists would drive faster on emptier roads and from motorists distracted by trying to work out what they owed as they drove through different areas.

Another consequence of road pricing could be people moving from cities to rural areas.

The Campaign for the Protection of Rural England said a road-charging scheme "would simply shift the problem rather than solve it".

The Government's feasibility study said road pricing would impact on "where businesses locate and where people live".

The bulk of weekday traffic is business-related. What happens if the cost of this goes up? What happens to people's ability to go to work? Has anyone calculated the cost of road charging to UK business?

And does anyone earn the money to pay the proposed charges?

-Andrew Abaza, Brighton