Yes, driving a car in public, where people can see you, while naked from the waist down is illegal due to the risk of obscene exposure. If you're wearing underwear or a swimsuit, you could likely get away with it - but maybe ask yourself why it's essential to leave the house without pants on in the first place.
While our research into road safety laws across Australia didn't raise any specific red flags for driving without pants on, we found that laws surrounding public nudity exist in all states and territories of Australia. Driving without pants on isn't really a safety issue - like driving without a horn or driving with one headlight out - so it's not something you can search on a road authority website, but it's definitely addressed in other parts of the law. Specifically, the parts that cover decency.
The wording and penalties associated with laws on obscene exposure differ for the different states and territories of Australia, but according to FindLaw Australia, obscene exposure is illegal in all states and territories.
Having said that, it's also important to note that intent is required for you to be convicted for obscene exposure; as Armstrong Legal advises, if you can prove that you were nude out of necessity or duress and not with the basic intent of exposing yourself to others in public, then you're not guilty in the eyes of the law.
While we couldn't find any clear information on how driving without pants could affect your insurance, it's likely that getting caught with your pants down, or off, or nowhere in sight, could make the process of calling up roadside assistance, or dealing with police at a collision, embarrassing at the very least, and quite suspicious at worst.
Unless you're a Calvin Klein model showing off the latest season's briefs, maybe just do yourself and everyone else a favour and chuck some jeans on before dashing out the door.
This article is not intended as legal advice. You should check with your local road authority to verify the information written here is suitable to your situation before driving in this manner.
Have you ever gone for a drive in your birthday suit? Tell us about it in the comments.