Given the desperate need to unclog the roads in most cities, and to fight pollution, the Centre's plan to liberalise taxi licencing to allow private cars to function as taxis\/undertake commercial ride-sharing should seem welcome. Of course, states have to get on board, first. That said, the Centre must ensure that licensed private cars ply only via a recognised platform\u2014like a taxi-aggregator service such as Uber and Ola\u2014so that accountability in case of any mishap can be affixed. If licences are handed out for private cars to be operated as taxis independently by owners\/drivers, it would lead to a monitoring nightmare. On the other hand, a digital aggregator platform will allow for antecedents check as well as real-time tracking while an independent model may not. Passengers would think twice about engaging a cab service that offers no procedure for grievance redressal. Also, The Economic Times reports, the Centre is mulling over various international models to see if there is one that can be emulated to ensure professional cab-drivers interests are not hurt. As per the report, the Singapore model, where private cars are only allowed two shared rides per day, and the US model, where there is a cap on the money a private car-owner can earn off shared rides in a year, are under consideration. There is a trade-off here that the government must give due thought to. While restricting commercial operations by private cars will contain any opposition from cabbies to the move, and thus ensure a smooth transition to the new regime, the fact is that environmental gains of increased ride-sharing could be significant, especially for a city like Delhi that must do all it can to control pollution. It will be a tricky road to traverse, given both livelihoods and pollution are pressing concerns.