CHICAGO (CBS) — The Chicago Inspector General’s office says scheduling errors involving the crews that immobilize vehicles with the Denver boot have cost the city $160,000 per year.

But WBBM Newsradio Political Editor Craig Dellimore reports the problem has been corrected.

Inspector General Joe Ferguson says the problem started because the booters—who immobilize the cars—are in a different agency from the dispatchers—who tell them where to go.

The city decided to add a night shift in 2009.

“There were three separate positions required to staff that function – booters, dispatchers, and security personnel,” Ferguson said. “When they went to the night shift, they simply didn’t align the schedules of those three separate employee components.”

So for the last part of their shifts each night, the booters had no dispatchers, and just did nothing.

The city’s comptroller, who has inherited the boot crews, has fixed the schedules. So the meter on this mistake stopped running at $320,000.

LISTEN: WBBM Newsradio Political Editor Craig Dellimore reports