I've been told before that if you get a crack in your windshield, you should change it right away: that it is dangerous to drive around with a crack in your windshield.
On the other hand, I know several people who have driven around with major cracking in their windshields for several years without any trouble. How dangerous is this really?
There are limits on the amount of cracking allowed on a windscreen before it fails safety inspection. Obviously, if your car isn't in a state/county that requires safety inspection, that's irrelevant.
What is relevant is the fact the windscreen is an integral part of the structural strength of the car. If it's cracked, it's weakened, and may cause more damage in an accident.
Cracks in a windscreen never heal themselves, and only ever get worse. I'd recommend getting them fixed quickly, but I wouldn't drop everything and run to the windscreen store.
