It took the MTA 31 months to start the process of fixing an escalator at an East Side subway station — one of several examples of agency foot-dragging that forces straphangers to take the stairs, according to a new report.

The escalator at the 53rd Street and Lexington Avenue station broke down in Sept 2008, but the MTA didn’t alert the owner in writing until this past April — a delay that stalled the already lengthy repair process, according to the agency’s Inspector General.

It’s one of 33 privately-owned escalators and elevators in the subway system that the MTA has done a lousy job managing, according to MTA IG Barry Kluger.

“The public has been seriously dis-served by the excessive amount of time that privately-owned and maintained escalators . . . have been out of service,” he said.

While a lot of the blame falls on the owners, the MTA is also shirking some of its duties, Kluger said.

Even though the MTA is responsible for alerting the owners when there’s an outage, they have no written policy for making sure the work gets done.

At one point the Station Environment division — responsible for making sure the equipment is operating — didn’t know the exact amount of privately-owned lifts in the system “Even though these escalators and elevators don’t belong to the MTA, we know that prolonged outages impact our customers in a way that is unacceptable,” said an MTA spokesman.

“MTA personnel has already begun to regularly inspect this equipment, and will log and post outages on mta.info and provide periodic status reports to the MTA Board. We will also take a more aggressive approach to address outages, partnering with the City to force the companies’ responsible to restore service as quickly as possible.”