99% of Delhiâs DTC buses to be retired in 5 years 
As much as 99% of Delhi Transport Corporation's (DTC) 3,951 buses will have to be retired over the next five years, according to reports. The operational life of a bus is 12 years or 7.5 lakh kilometres, and 21% DTC buses are already 'over-aged'. Notably, three attempts to procure new buses have failed because of tender issues. 