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


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.

Outside the vehicle,

the danger of being crushed by the vehicle is greatly enhanced.

  • Finally, there is the integrity of the passenger compartment.

    Years ago, most vehicles had steel A-pillars to support the roof.

    Today, it is the windshield that provides much of the support that

    prevents the roofs collapse during vehicle roll-overs.

  • There are a few common sense tips people can follow to ensure

    their windshield performs as intended. The ideal scenario calls for

    saving the original windshield installed by the factory. The

    conditions inside the factory for installing a windshield are

    perfect, so the confidence level in the factory seal between

    windshield and vehicle is highest. If the original windshield is

    damaged, there are two choices. Either repair the original

    windshield, or replace it. The advantage of repair is the factorys

    safety seal is not broken. The windshield is not removed from the

    car. That saves both the very expensive windshield and the safety


    Many people are unsure if their windshield can or cannot be

    repaired, so it is extremely important to consult a competent auto

    glass service provider for advice. If you are not sure, it is always

    a good idea to ask local service providers if their technicians are

    certified by the National Glass Association.

    If the damage is beyond repair, then windshield replacement is

    the only other alternative. If replacement is indicated, ask if the

    auto glass shop endorses the Auto Glass Replacement Safety Standard

    (AGRSS) and trains their technicians to that standard.

    For more information on auto glass safety, you may call

    1-800-CAR-HELP toll-free and select the Damaged Auto Glass menu

    option, or, visit  and

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