Your Windshield IQ -- What You Don't Know Could Be Dangerous

The five most important safety functions your windshield performs

Most of us would conclude that

our windshield was a very useful piece of equipment. It

keeps cold and heat; wind and rain; and untold numbers of bugs and

other airborne road debris out of our faces.

The problem is that consumers have different and more limited

expectations from the windshield than the automotive engineer. In

other words, we worry about water leaks or ugly "dings" and cracks

affecting our car's value, while the engineer understands how such

damage can affect the vehicle's structural integrity and passenger

safety.

The fact is that the modern automobile and truck, windshield is

part of the vehicle's safety restraint system (SRS) that also

includes air bags and seat belts. If any of these safety components

are damaged, or are inoperable for any reason, the effectiveness of

the entire SRS could be compromised.

The SRS is designed to keep vehicle occupants within the relative

safety of the passenger compartment during accidents, head-on

collisions and roll-overs. The National Highway Traffic Safety

Administration reports over 40,000 Americans are killed and over 5

million injured every year in highway crashes. Over 30

percent of the fatalities occur when vehicle occupants are

either ejected from the vehicle, or, injured during rollovers.

Windshields are intended to keep occupants inside the vehicle.

The windshield also supports the roof thereby preserving the

structural integrity of the passenger compartment and keeping it

from collapsing and crushing driver and passengers.

Seen from this perspective of personal safety, consumers have a

vested interest in making sure any damaged windshield they replace

is replaced properly and safely. For these reasons every vehicle

owner should be aware of the five most important safety functions

performed by their windshield.

• The most obvious windshield function is,

  of course, visibility. Unlike drivers of old, we do not wear

  goggles that keep bugs out of our eyes or highway debris from

  hitting our face. Even so, the modern windshield can become pitted

  and scratched from minute dirt and sand particles. Pebbles and

  stones can fracture the glass causing dings that, if left

  unattended, can affect vision.

• The second windshield function is not as

  obvious. In many cars and trucks, the windshield supports the

  passenger side airbag during deployment. If a windshield is

  replaced improperly, the windshield could become detached from the

  vehicle in an accident. If this happens the passenger side airbag

  will not deploy properly.

• Thirdly, windshields cushion the blow if

  a vehicle occupant is thrown forward in a crash. Windshields are

  made of two layers of glass sandwiched around a layer of polyvinyl

  material. The glass may break but the polyvinyl layer is flexible

  and cushions the impact. This feature explains why windshields are

  made of glass not plastic. Plastic is rigid and unforgiving to a

  persons head and neck.

• The fourth windshield safety attribute is

  closely related to the third. When the windshield cushions the

  occupants impact, it also keeps the occupants within the relative

  safety of the passenger compartment. If the windshield becomes

  separated from the vehicle, the occupants could be ejected through

  the windshield opening and onto the roadway.