Although many models tried to be a tool for decision makers, developed models cannot prove the performance
level of the taxi markets. There are no optimum models of taxi supply to guide decision makers.
x Models proposed in the literature are characterized by significant data requirements due to the high number of
determinants in the taxi demand and supply. Actually, with the use of GPS and GIS, data recollection is
technically easy, but the reticence of the taxi sector to share this data is an important barrier.
x All the models have investigated the taxi market from the point of view of the taxi driver (income) and the
customer (waiting time, level of service, total cost), but no model has studied the consequences of the market
regulations on the city (contamination, congestion). It is important to add environmental considerations as a
determinant factor in the future models since in most of the cities, taxi flows have not only negative
consequences on the rest of the traffic, but also in the citizen’s health.
x Regulation of entry and fares must not act together; deregulation of access to the taxi market must be achieved in
most of the cities, increasing the supply and the level of service of customers. Entry deregulation must be
accompanied with new regulations, such as fare regulation (almost with a maximum fare control) and special
regulations on high-demand generation points, such as airports, train stations or hotels.