NEW DELHI, Oct. 15 -- The Centre has decided not to extend the validity of expired transport documents such as driving licences beyond October 31 and has advised state transport departments to clear the backlog of applications within a month. State governments, however, can offer further extensions at their level if they deem it fit, people aware of the matter said. The Delhi government has already decided to extend the validity of expired transport documents till November 30 provided they were issued by the city government....