The audit released Monday also found that MARTA is spending $50 million above the national average for employee benefits.
The Atlanta Journal-Constitution reported results of the KPMG audit. It was commissioned by the Metropolitan Atlanta Rapid Transit Authority's board of directors to give it a blueprint for stabilizing finances and expanding its services.
The audit also found that MARTA could save between $60 million and $142 million over five years by outsourcing many functions.
It found that a high rate of employee absenteeism cost MARTA about $11 million a year, while worker compensation claims were costing $5.5 million more than the national average.