The Delhi Transport Department on Monday banned BS III petrol and BS IV diesel vehicles from city roads till December 9 or till air quality improves. “As per directions provided under Stage-III of the GRAP and under section 115 of the Motor Vehicle Act, 1988, it is hereby ordered that there shall be restrictions to ply BS III Petrol and BS IV diesel light motor vehicles (four-wheelers) with immediate effect, till December 9, 2022, or till downward revision in GRAP stage, whichever is earlier,” the order stated. The commission for air quality management (CAQM) had invoked GRAP measures under Stage III on Sunday. This included a ban on construction and demolition activities.