1. Possibly reasons like this:
https://archive.is/tjdZ2 ... to save you the click, the title/subtitle reads:
> When Getting Out of Jail Means a Deadly Walk Home
> Nearly every day in Santa Fe, N.M., people released from jail trudge along a dangerous highway to get back to town. Jails often fail to offer safe transport options for prisoners.
2. You must have a preference for walking, since a bicycle would be at least 3x and as much as 10x faster than walking.
3. The thousands of dollar number seems misleading. If you bought a car solely for this purpose, yes, I believe you're right. But that seems unlikely. The actual marginal cost of using a car you already owned for this purpose is on the order of $3-500.
I commend and support what you do (though I prefer to use my bike when I can). But I don't think the financial benefits should be overstated. There are, of course, other benefits.