Hackney carriage which a taxi may operate and include regulating the taximeter (not compulsory until 1907), the maximum age of the taxi (not more than 15 years), advertisements and the turning circle of . As part of the Transported by Design programme of activities, in 15 October 2015, after two months of public voting, the black cab was elected by Londoners as their favourite transport design icon. In London, hackney-carriage drivers have to pass a test called The Knowledge to demonstrate that they have an intimate knowledge of the geography of London streets, important buildings, etc. Learning The Knowledge allows the driver
Hybrid taxi hybrids. Clean Air Cab claims to be a carbon-neutral taxi service. In addition to lowering emissions with its hybrid fleet, the company purchases carbon offsets and supports global reforestation by subsidizing the planting of 10 Brazilian rainforest trees monthly for each cab in service. Through an ordinance, the city of San Antonio, Texas introduced a voluntary program in 2007 that allows taxi owners to swap the permit of one non-hybrid car for two permits valid only for hybrid electric vehicles. To prevent one fleet from obtaining all the permits, the largest company is allowed to replace only 1% of its