In Snohomish County, Washington, their legislators in 1991 passed a law titled "the Commute Trip Reduction Act".

On specific congested road corridors citizens are paid to use non-auto modes of transportion.   For example, if you bike to/from work 8 days per month on these specific congested corridors, you might receive $50.00 per month.  

There is also a brokers payment for persons already in the program who bring in more patrons to the program.  

Snohomish's "Curb the Congestion" web site explains the rules in detail - and there are quite a few details - for example preventing persons who would claim they need to use one of the congested corridors for commuting in order to receive payment, when, in fact, they did not use, or need to use, a congested corridor.

What other systems do you know of which pay persons to not use cars?

What other locals do you know where money is used to incent persons to travel in a non-auto?