An Independent Budget Office report found that straphangers have been facing increasingly long wait times on subway platforms since 2012.

At the end of that timeframe, the report found that riders lost 45 percent more passenger hours to delays. 

The nonpartisan city agency says the delays cost riders a collective $300 million a year.

The largest increase came on the J/Z line, which runs from Queens, through Brooklyn and into Manhattan. Wait times along the line increased by 71 percent.

In total average hours lost, the worst line was the No. 5 train, which runs from the Bronx, through Manhattan and into Brooklyn.

Brooklyn Borough President Eric Adams initially requested the study to see how much time city commuters lost to delays.

Both the MTA and the IBO say some of the data used in the report was out of date, and transit officials say they'll have more accurate data soon.