Thanks for the tips on the check engine light. (By the way, my car is a 97.) I was going to bring the car to the dealer to have the check engine light reset, but they said I should instead wait a few days and see if the light will go off by itself--otherwise, they charge $$$ to check out the problem. We'll see what happens.

A little additional info--a minute before the car stopped, it was very sluggish, barely accelerating while I was on a flat highway. When I got off the highway I had to go up a hill, and then the car finally conked out. Perhaps I could've gone a bit farther if I hadn't hit the hill, but the way the car was dragging on highway, I'm guessing it didn't have much juice left.