Isn't the new proposed road-pricing tax wonderful? What is amazing is the accuracy of the numbers they throw out -- from 2p on rural roads upto £1.34 for inner cities. Surely at this stage it is the concepts that are being discussed, but when you see numbers of such spurious accuracy, one wonders how much has already been decided...

But what is the purpose ? To reduce congestion or to raise revenue? I would argue that you have to focus on one of these issues, not both. You can only serve one god well.

The problem is that the Government raises an enormous amount of money from the existing wonderful petrol tax, and it's certainly not all spent on roads. So any new scheme is going to have to raise at least as much money to keep the money flowing in, otherwise we'll need more tax elsewhere.

And if congestion is genuninely reduced, then there will be less cars, so less money.

And of course, the new scheme would need special technology, which would have to be paid for by somebody -- that's us !

Suppose your car does on average 50mpg -- and there are plenty of cars out there that do.

Suppose you drive only on the '2p rural roads'.

For your gallon, you are going to pay 50x2 or £1 in road-pricing.

Lets say petrol costs 90p a litre, and there are 4.5 litres to a gallon. So to break even you need to see petrol reduced in price by 22p a litre , or 68p a litre...

Of course most of us will be on roads costing much more than the 2p rural rate. At 10p a mile and 50mpg, they would have to pay you 20p a litre as a subsidy!

For the more luxurious 20mpg gas guzzlers, 10p road pricing on average would need petrol at 46p a litre. Highly unlikely, it's not that cheap in France.

Two things are very clear :

a)This is about raising money.

b)It penalises people who drive economical cars.

Time for the government to decide which god to serve!