"Employer-paid parking is the most common fringe benefit offered to workers, and the cost of all this free parking amounts to about 1% of national income. Almost everyone who can park free drives to work, but taking away any fringe benefit is difficult.
There is an ingenious way out of this dilemma: Employers can offer commuters the option to "cash out" the value of their free parking. Commuters can continue to park free, but the cash-out option encourages them to consider alternatives to driving to work alone. Would you walk, bike, carpool or ride the bus to work if someone paid you to do it?"
Thanks to Chris Steins