MUMBAI // Three-wheeled auto rickshaws have been a common sight on Mumbai's roads for decades but the state transport department has put forward a proposal to phase out these heavily polluting, unsafe vehicles. The proposal is currently before the Maharashtra state cabinet and it plans to reduce the lifespan of auto rickshaws to seven years and offer financial incentives to drivers to replace their vehicles with small cars. Drivers will not be able to re-register their old rickshaws if the plan comes into effect. The plan also includes a measure for auto rickshaws to be converted to run on compressed natural gas during the phasing-out period. "The accident rate for three-wheelers is higher, with most of the accidents being fatal. It's high time the autos are replaced with four-wheelers," said Radhakrishna Vikhe Patil, the Maharashtra state transport minister.