board a second bus within one hour for the same fare. Under Khan, paper and coin cash transactions became obsolete and the Oyster system was expanded to include debit and credit cards. This initiative was started under his predecessor, Johnson. Upon election, Khan outlined a vision to make London the "greenest city" by investing in walking and cycling infrastructure while reducing polluting vehicles. In 2019, the "Ultra Low Emission Zone" scheme was launched which taxes highly polluting vehicles in its covered territory. London declared itself the world's first "National Park City" (effective from July 2019), reflecting its unusually high amount of green space for a city of its size. Extended term The Government postponed all elections due in May 2020, including for the mayor of London, for one year due to the COVID-19 pandemic. Khan had therefore served a term in office of five years rather than four, which ended in May 2021. He was re-elected in 2021 for a further four-year term, defeating the Conservative candidate Shaun Bailey. See also Foreign relations of the Mayor of London Leaders of the Greater London Council Notes References External links Page about the process of nomination Local government in London London 2000 establishments in England