HR type here. About 25 years experience most included staffing for at least one of the hats I wore.
felonies and misdemeanors are definitely crimes. If the questions asks for "crimes" you have been convicted of or plead guilty to, you would list that. And unless the job was a driving job or it happened in the last year or two, other than a raised eyebrow over wtf is "Obstructing a highway"?? It shouldn't be a problem.
The problem comes when you say no and if they run a background check and it shows up. Now you have a falsified application. A lot of companies will terminate right then and there. I know I get really pissed when somebody lies to me , and depending on the situation and what is falsified I have about a 50/50 record of recommending discharge. Falsifiying an application indicates that you are willing to be dishonest with the company, when you look at it that way, you can see why the reaction is the way it is. Are you being hired to handle money, handle valuables, etc?
It's a relatively minor thing shouldn't be a problem if listed, a major problem if not.
They can only ask about convictions not arrests, however a company that asks about arrests and you tell them they can't ask that is not going to be happy with your interview. I've had people tell me my question is illegal. When that happens I explain why I asked it and why it concerns a bona fide occupational qualification. And if I am asking a borderline question like that I make sure I ask everybody and record their answers. I recruited for a company that had involvement with testing of strategic weapons systems and junior engineers were often tasked to participate in test shots to Kwajalein or Ascension Island. One woman, "You can't ask if I can travel, you just want to find out if I'm married and have kids because of the insurance cost. That's illegal." "No, in this job, you can get as little as 24 hours notice before you have to leave for a test. It takes 2 days to get there, and then the customer may delay the test for a variety of reasons. And you can't go home until the test is done. So if that's something you can't or are unwilling to do, finding out now saves everybody time and money. Can you do it?"