Taxi commissions make a significant amount of money from Taxi medallions. They can cost anywhere from $200k-$1 million dollars each in some cities.

In NYC the taxi commission is in the pocket of the medaillion holders. That's why the recent law to issue more mediallions (2,000 at ~800k each = $1.6b for the city) had to go through the state instead (Albany being less corrupt than anything is mind-boggling), until of course a judge knocked down the law and said only the city could do so.