In Sweden, taxation of road traffic is an important element of transport policy, providing an instrument to influence the composition and turnover of the motor vehicle fleet, thus improving its average fuel efficiency. Since 1991, the tax on petrol and diesel includes a carbon dioxide tax. A VAT was imposed on petrol in 1990, and has since been raised to 25%. Sweden also levies sales tax, annual vehicle tax and user charges. Sales taxes are levied on light vehicles only. The annual vehicle tax is differentiated according to vehicle weight and fuel. Only heavy goods vehicles are charged so-called user charges (Eurovignette). Changes have been made to the taxation of company cars so that drivers pay for fuel either directly or indirectly.