1. THE facts in this case are shortly as follows:-The petitioner No. 1 is the owner of seven buses and the petitioner No. 2 is the owner of a bus. These buses used to ply on route No. 12c in Calcutta, which runs from Howrah Station to Barisa. Until the year 1954, the said buses were running on route No. 33 which runs from Paikpara to Chetla. Sometime in 1954, an agreement was entered into between the petitioners and the Regional Transport Authority, Calcutta, whereby the petitioners and certain other permit-holders withdrew their buses from route No. 12c to route No. 33, running from Paikpara to Chetla and they were doing so under permits granted from time to time. The Indian Motor Vehicles Act (Act IV of 1939) (hereinafter referred to as the said 'act') was amended by the Motor Vehicles (Amendment) Act, 1956 (Act 100 of 1956) which received the assent of the President on the 30th December, 1956. Under the said Amendment Act, a new chapter, being chapter IVA was inserted in the said Act, containing special provisions relating to Nationalisation of transport and the creation of a State Transport Undertaking. In West Bengal, the Directorate of Transportation, Government of We