Driving with a chipped windscreen is generally not safe and is often illegal. The primary risk is that the chip can quickly develop into a large crack, significantly compromising the structural integrity of the glass. A damaged windscreen is weaker and may not provide proper protection in a rollover accident or properly deploy the passenger-side airbag, which often uses the windscreen as a backstop. The chip can also distort your view of the road, creating a dangerous blind spot.
The decision to drive depends heavily on the chip's size, location, and depth. Most safety standards, including those from the National Highway Traffic Safety Administration (NHTSA), advise that any damage in the driver's critical line of sight is an immediate fail for vehicle inspection. Modern windscreens are made of laminated glass, which consists of two layers of glass with a plastic interlayer. While this design prevents it from shattering into large pieces, a chip weakens the entire assembly.
| Repair vs. Replacement Guidelines (General Industry Standards) | |
|---|
| Repair is often possible if: | Replacement is typically required if: |
| Chip is smaller than a quarter (approx. 1 inch/25mm) | Crack is longer than a dollar bill (approx. 6 inches/15cm) |
| Damage is not in the driver's direct line of sight | Damage is deep enough to have penetrated the inner layer of glass |
| It is a simple bullseye or star-shaped chip | The chip is at the very edge of the windscreen |
| The damage is not older and contaminated with dirt | Multiple cracks are emanating from the point of impact |
Your immediate action should be to have the damage assessed by a professional auto glass technician. Many repairs are covered by comprehensive insurance with no deductible. Avoid extreme temperature changes, like blasting the defroster on a cold window, as this can cause the chip to spread. Ultimately, erring on the side of caution is the safest approach for you and your passengers.
