I did most of my commuting in Colorado where thunderstorms were a nearly daily afternoon event in the summer months only. Most were dry, lightning only, some were severe with damaging hail and winds, etc. In the afternoon I could often time the commute between storm cells. It's hard to go out into a storm you know will blow over in 20 minutes.

On the open road, I try to do the same--sometimes you can see squall lines, storm cells approaching, especially out West. I do the count--if it's less than five seconds from flash to bang, lightning is less than a mile away and it's time to get serious. If it's visibly passing way behind or off to one side, I'm not as worried. It's sort of a game to race a storm to shelter, whether it's a town or a spot I can quickly throw up my tarptent for an hour or so. Sometimes you just get nailed. Poor visibility and wind bother me more than the threat of lightning. I have this stupid rationalization that I'm riding on rubber tires and that insulates me--right. I don't like being the highest thing around, that's for sure.