Congestion Charging for Bristol is in the news due to efforts by the Bristol Conservative Group and the Bristol North-West Prospective Parliamentary Candidate Charlotte Leslie to hold a referendum prior to any local initiative.

Road Pricing is not intrinsically a bad idea - markets are the best way to allocate demand for scarce resources, and nothing is more scarce in Bristol than road space.

But there are two principal arguments against a London-style congestion charge. The marginal level of taxation and the costs of implementing the system.

Drivers pay a lot of tax - Road Tax, Fuel Tax, VAT on services and MOTs - and these existing taxes are in the control of central government. Would congestion charging be an alternative to these taxes? Hell, No. A locally administered congestion charge is an extra chunk of your monthly pay check that you don't get to keep.

If these other taxes were abolished, road pricing could be a very effective form of Pigouvian tax, providing drivers with a market signal to indicate the negative consequences (or externalities) of their individual choice to drive and allow them to make a corresponding decision: pay the price, or change their behaviour to avoid it.

The mysterious Bristol Blogger does an excellent job of disproving the proposition that a Congestion Charge raises money for public transport. Conservative councillor Phil Taylor has already demonstrated that Transport for London more or less breaks even after paying for all those fancy cameras and number-plate recognition computers.

Even assuming it makes sense to subsidise buses and public transportation from general taxation, this solution will not achieve that purpose. Some will argue that the London Congestion Charge was effectively a prototype, and that future enormous public sector IT projects of the same kind will be much cheaper. From my own experience in the management and delivery of IT projects, I'm very sceptical of this attitude. Consider the CSA, Inland Revenue, MTAS, NHS Spine or classics like the London Ambulance Service.

As an alternative, local councillor Tim Kent suggests using parking spaces as a proxy measure for road use. This concept has a lot of merit, in that it does not require huge investments in IT to administer, and there is some scope for local government to lower business rates to compensate for double-dipping by Westminster.

The outcome of the current debate will certainly provide one clear signal - whether the Labour administration in Bristol is willing to set aside last century's ideology and work toward reducing congestion, or whether they are just mirroring Gordon Brown and seeking tax from wherever they can.

I posted a couple of quick graphics on the UK budget last week. I'll see if I can do the same for our city.