Road damage caused by a vehicle is proportional to the fourth power of vehicle weight. That leaves out other externalities such as deaths and injuries caused to pedestrians, cyclists and people in other motor vehicles.
But taxes should reflect externalities, so a bit part of vehicle tax should also rise as the fourth power of vehicle weight. Double the weight, sixteen times the tax. I’d make enforcement simpler by setting a zero-rate mimimum of 1000 kg.
By the way, use of this formula also illustrates the imbecility of those demanding a tax on bicycles. If the base rate is, let’s say, £100 per annum for an unladen 1-tonne vehicle, then that for a bike weighing 20kg would be £100/100**4. That is, 1/10,000 of a pound, or 1/100 of a penny. And other bicycle-caused externalities aren’t much different in proportion to those caused by a motor vehicle.
Road damage caused by a vehicle is proportional to the fourth power of vehicle weight. That leaves out other externalities such as deaths and injuries caused to pedestrians, cyclists and people in other motor vehicles.
But taxes should reflect externalities, so a bit part of vehicle tax should also rise as the fourth power of vehicle weight. Double the weight, sixteen times the tax. I’d make enforcement simpler by setting a zero-rate mimimum of 1000 kg.
By the way, use of this formula also illustrates the imbecility of those demanding a tax on bicycles. If the base rate is, let’s say, £100 per annum for an unladen 1-tonne vehicle, then that for a bike weighing 20kg would be £100/100**4. That is, 1/10,000 of a pound, or 1/100 of a penny. And other bicycle-caused externalities aren’t much different in proportion to those caused by a motor vehicle.