Global energy demand has continued to be supported by conventional technologies and fossil resources, with energy intensity unable to be significantly reduced. Air pollution is one of the main issues facing large urban centres, but there are no structural changes allowing a substantial reduction in emissions. Many cities set restrictions on car traffic, not only because of environmental issues but also because of congestion, encouraging the emergence of a number of car-sharing and ride-hailing solutions, which partially replace public transport. Electric vehicles cannot be considered an alternative, because cities lack charging points and the batteries have an insufficient autonomy to handle urban traffic jams.