I want to be run over.
Why would you want to be run over?
I'm thinking existential thoughts but I don't have a special reason.
You shouldn't wish harm upon yourself for no reason. Talk to someone about your thoughts and see if they are there for any particular reason you might need help with.
I don't want to talk to anyone. I'll throw myself on the road and it would be kind of fun I guess.
It's really troubling that you seem to wish to harm yourself. There must be a reason that you are having these kinds of thoughts, you should get some help to figure out what it is.