Key Performance Indicators

Bus Mean Distance Between Failures

Definition: An industry standard that measures the mechanical reliability of the fleet. It measures the average bus miles between National Transit Database (NTD) reportable mechanical failures i.e., incidents precluding a revenue vehicle from completing its trip, or starting its next scheduled trip. Currently, all mechanical breakdowns are counted as failures, thus exceeding the number of failures reported to NTD. 

Performance (January 2017):

In January, did not meet the Target; the actual being 3,046 miles. The overall number of breakdowns increased from 651 in December to 785 in January. The number of Engine system failures increased by 12%, that of HVAC system failures decreased by 15%, that of Cooling system failures increased by 59% and that of Brake system failures increased by 41%.  


  1. Continue conducting the troubleshooting refresher training at all garages
  2. Replace coolant sensors and defroster valves on selected bus models