> There's a significant difference, in that you choose to take on credit card debt, but you don't choose to be fined.
You choose to buy things on a credit card, sure, but you also choose to do the acts for which you are fined. And you can say that traffic enforcement is arbitrary, so that the costs may not be predictable -- but, then, the same is true of post-transaction changes to credit card policies and interest rates which impact the degree of indebtedness you actually end up with. (And, of course, since in many cases fines can be paid by credit cards, any arbitrariness and involuntariness that applies to fines can potentially directly produce credit card debt, so...)
I don't see how credit card policies are arbitrary in anything like the same way traffic enforcement is. The policies are explicitly spelled out and in my experience they are enforced pretty much uniformly. Make a late payment, get charged. Pay less than the full amount on the card, get charged interest based on a rate that was listed when you signed up. It's easy to have a credit card and avoid the fees, and if you do something wrong then it's predictable what will happen.
With traffic citations, it's nearly impossible to go somewhere without violating the law in some way and even more impossible to do so safely. Your odds of getting caught are slim, and your odds of being punished depend entirely on the discretion of the officer who caught you.
Further, it's possible and not even very difficult to go through life without ever having a credit card, whereas it's impossible to go through life without ever being subject to traffic enforcement. (Even if you never drive or bike, there are crazy laws for pedestrians too.)
"since in many cases fines can be paid by credit cards".
Less and less so, actually. "We accept only cash and check (or even cashier's check". On one hand, I realize that there's a merchant fee involved in payment by card, but it's also a convenient way to make payment inconvenient.
Actually, I have a traffic violation in the mail I need to resolve. The letter from the city says "YOU MAY PAY BY CHECK OR MONEY ORDER ONLY. WE DO NOT ACCEPT CREDIT OR DEBIT CARDS. DO NOT SEND CASH IN THE MAIL."
You choose to buy things on a credit card, sure, but you also choose to do the acts for which you are fined. And you can say that traffic enforcement is arbitrary, so that the costs may not be predictable -- but, then, the same is true of post-transaction changes to credit card policies and interest rates which impact the degree of indebtedness you actually end up with. (And, of course, since in many cases fines can be paid by credit cards, any arbitrariness and involuntariness that applies to fines can potentially directly produce credit card debt, so...)