The ratio of vehicles to road length is on the rise in Delhi and with roads already occupying 21 percent of the capital's area, there is limited potential for more roads in Delhi. Delhi which lags behind Kolkata and Mumbai in terms of public transport, needs to improve upon this aspect to check the rapidly increasing numbers of private vehicles on its roads. A World Bank study conducted on the percentage distribution of urban trips in selected Indian cities, including , Delhi in 2002 showed that while Kolkata led in public transport trips(65 percent), Mumbai counted for baout 60 percent of such trips.