Motorists in London are avoiding Mayor Ken Livingstone's congestion tax by registering their automobiles as taxis. The £8 (US $16) tax is imposed on any vehicle entering the city's downtown area during peak times -- except for cabs.

Transport for London's Public Carriage Office is responsible for tracking 46,000 vehicles licensed as "for hire." A motorist with a sufficiently clean record can obtain a license by taking a simple eyesight and 40-minute road test administered by the Driving Standards Agency. The test costs £62.50 (US $125) and the license itself is renewed annually for £27 (US $54).

A few trips to London make signing up as a cabbie a good deal for drivers of certain SUVs and luxury cars, for whom the tax rises to £25 (US $50) per day in February 2008. Transport for London began a tax avoidance investigation, the Evening Standard reports, after it noticed taxi registrations for expensive vehicles such as the Porsche Cayenne, Aston Martin DB7, Maserati Quattroporte, Bentley Continental, and Maybach 62. All of these vehicles would otherwise be subject to the extra tax.

London's motoring public is not alone in rejecting Livingstone's program. Since 2005, US Ambassador to London Robert Holmes Tuttle has refused to pay the congestion charge because it is effectively the kind of tax from which all diplomats are exempt, as they pay the income taxes of their home country. The US embassy is joined by several other nations, including France, in its refusal to pay.