In the interest of clarity, I want to point out that #1 is arguably a logical subset of #2. If the car can travel without anybody driving it, someone who doesn't drive can travel in it. Based on your comment about legality though, I'm going to assume you mean someone who is missing their license or for some other reason can't drive.
In any case, this very much looks like #1 to me.
人が運転しなくても走る車
Is pretty clearly "A car that will travel even if (the) person is not driving". There's no information here about the person's ability to drive. If you wanted to say something like "a car usable even by people who cannot drive", I would expect it to be something like:
運転できない人でも使える車
Lastly, while I agree this is probably not going to be legal in the states for quite a while, I want to point out that the article is about an event where various companies are introducing new products, presumably ones that they feel are particularly representative of technological advances on their part. Companies often do this more to show that they have the technology than with the intent of using it immediately. That, and I wouldn't expect a simplified news article to go into detail about legalities anyway.
Edit: Since する (in 運転する) is present/future tense, one could argue that it should be read as "A car that will travel even if (the) person does not drive". However, this is ambiguous in English anyway (does not drive in general? does not drive that car?), and consequently I would expect that in either language if somebody meant to specify that the person did not drive in the general sense they would make it more explicit. Particularly in Japanese where there are options to specify "a person who doesn't drive" as "運転しない人", the phrase "人が運転しなくても走る" really looks like it's talking about #1 to me.