Pay-per-mile road taxation, also referred to as road pricing, would require drivers to pay a higher Vehicle Excise Duty based on their annual mileage and the environmental impact of their vehicle. In essence, those who drive fewer miles would pay less, while those who drive more would contribute more due to their greater road usage.

Regardless of whether a pay-per-mile system is implemented, the RAC anticipates that the government will eliminate the current five-pence reduction in fuel duty. Williams has noted that this discount is costing the Treasury £2 billion annually.