The taxicab makes a significant contribution to the accessibility of a city, and provides a wide range of services across many different social groups and urban environments. This study considers the roles and functions of the taxi from its origins as the first licensed form of public transport, to the current variations of vehicle type and operation, to predictions for its future development. Also addressed here is the impact which this ubiquitous form of transport has on contemporary urban life, and the analytical tools being used and developed for its licensing and control.