This is the number one enemy of a chipped windshield. Glass expands in the heat and contracts in the cold. If you have a crack, this constant movement puts stress on the damaged area.
The general rule of thumb in the auto glass industry is this: crack in windshield spreading
Furthermore, most states have laws regarding "obstructed vision." If a crack spreads into the driver’s primary line of sight, you risk receiving a traffic citation. In many regions, a crack longer than a credit card or one that reaches the edge of the glass will automatically fail a vehicle safety inspection. Immediate Steps to Take This is the number one enemy of a chipped windshield
A spreading windshield crack is a positive-feedback mechanical system: as the crack lengthens, the stress intensity factor increases, accelerating further growth. Environmental factors (thermal gradients, vibration) reduce the critical crack length threshold by up to 60% compared to laboratory conditions. Drilling stop-holes provides temporary, unreliable arrest at best. The general rule of thumb in the auto
