I have a 2002 honda civic. The other day I was driving and I noticed that the speed odometer needle was on 0. Later on it started working again, then quit again the next day and then started again. What would do this?

I believe your vehicle has a speed sensor which tells the vehicle how fast you are traveling. Older cars used to have a cable but if I'm not mistaken, I believe you have a sensor. I would try replacing that first.