In India it's not even "speed money" that you used to have to pay (don't know how bad it is these days). It's "being allowed to play" money.
we call it "service charges".
the officer has discretion to impose taxes, interest or penalty and on payment of service charges, discretion to look away, not mention the issue for later on.
in case the issue arises, or goes to litigation, service money ensures the officer will say yes its good to any reply you give.