Useful...

As much as insurance has sky rocketed...I don't have to worry about it. I also don't have to worry about it doubling or trippling if I'm in an accident. This is an anxiety many people face (and I've not heard one person say they enjoy it). And as I've said before, getting rides with people keeps me in company and gives me a chance to talk. As into myself as I am...this helps a lot. There are other people out there whose interests are different Han mine...When I ride along with them, I can see what they are, and find something new to be passionate about.
Sometimes, running errands with people is a cooperative effort...I mean, I might be keeping drinks.from spilling, or reading the map, or keeping restless kids down in their seats. This is all important...especially when a driver can't get to these things, and it prevents accidents.
Sometimes...it's keeping the driver awake. How many times have I come back from Disneyland in the middle of the night? Kudos to all passengers who have kept that driver paying attention!

Closer

If I didn't't depend on other people to help me get around...would I talk to anybody? Seriously. I'm la loner. Which isn't a bad thing. But who wants to ripen and then rot? I mean, people need SOME socialization, you know? Sure, some days I wanna hide under the covers and not come out--and I quite enjoy it. But weall need to connect with another human being once in in a while. If I drove everywhere--chances are this would be just one more thing I would do alone. And then I'd stil be alone there too. Rides are a chance tre-connect. Just for a little while, I can talk with someone and find out what' s going on with them.

"How can I pray for you?"
"Maybe we can do lunch."
"So, how did you do on that test?"

This gets me out and keeps me in the know (Even if it's just a little).
Besides that...it's something I can afford. No car payment; just gas money where it applies.
This helps someone else every once in a while.
Good conversation and some laughs, an encouraging radio show...and it gets me where I need to go.
Why not?