In Oregon, you can get a ticket for leaving your car door open too long. In California, it's illegal to drive in your bathrobe (but this only applies to ladies, so Hugh Hefner - you're okay). And in New Jersey, it's against the law to pump your own gas.
When every region has their own unique set of traffic laws, you're bound to come across some statutes that seem unusual. While some seem unlikely to ever affect you (such as the law in Chico, California, which states that you cannot plant rutabagas in a roadway), there are a few, like the ones I mentioned earlier, that might catch you unawares when you leave home.