But current behavior is influenced by current enforcement & penalties.

Where the penalty is often:

1) "Mr. Jones, you drove again? That's another $200 fine!" -- as you said, they can't/don't/won't pay, so what's the penalty?

2) "Mr. Jones, you drove again? I'm going to suspend your license for another 12 months!" -- how foolish is this? You punish somebody with the same punishment they've *already* ignored?

Start throwing people in jail (even for 7-10 days), and I think behavior would quickly change. As of now, too many suspended/restricted drivers simply don't fear the legal system.

Also ok with meaningful Community Service, when there is financial hardship.