What could cause a Honda Civic to shut off while driving?

One of the reasons it shuts down is because of moisture in the distributor cap. I too had a Honda civic and it did the same thing . Mechanics looked at it and neither of the 2 that I took the car to had an exact answer but moisture being the case.

If it is a moisture problem, to prevent it from happening again, take off your cap, and rub a thin film of vaseline around the edge, then replace the cap. don't glob it on, you just want a protective film around the sealing surface.