Due to its diverse and abundant public transportation, privately owned vehicles are not as common in Kolkata as in other major Indian cities.[180] The city has witnessed a steady increase in the number of registered vehicles; 2002 data showed an increase of 44% over a period of seven years.[181] As of 2004[update], after adjusting for population density, the city's "road space" was only 6% compared to 23% in Delhi and 17% in Mumbai.[182] The Kolkata Metro has somewhat eased traffic congestion, as has the addition of new roads and flyovers.