If you’ve ever had a cracked or damaged windshield, you’ve probably noticed how annoying it can be. More than being annoying, having a damaged front windshield can be dangerous. After all, they are made of glass, which can be structurally compromised by cracks and damage. For motorsports like racing, however, cars ditch the glass windshield altogether, adopting a far less common racing windshield material: plastic.

Polycarbonate windshields

Polycarbonate windshields aren’t legal for streetcars, but they are incredibly important safety features for race cars and track-only cars. For a while, glass windshields were still popular in the racing circuit, varying between tempered glass and eventually safety glass before they became obsolete altogether. There are a lot of reasons why polycarbonate is a better option for race cars, including driver safety.

The safer option

Polycarbonate windshields react differently under impact. Unlike your standard glass windshield, polycarbonate does not shatter when it is hit. This is because the material is softer and more flexible, it is a safer alternative. Although it is plastic, it is surprisingly strong and can hold up to the high speeds required by the sport itself.

The downside

Because the material used is softer than glass, it can become damaged much easier. While it won’t crack or shatter like a glass windshield will, the polycarbonate material can become scratched and pitted very easily as debris like rocks and sand come into contact with it at high speeds. As you could imagine, this can reduce driver visibility quite a bit.

That’s why polycarbonate windshields have a special layer over the top that most people don’t realize. You may have noticed a pit crew member removing a thin plastic layer that rests over the top of the windshield. This tear-off layer is a protective film that acts to protect the polycarbonate material and can be removed to improve driver visibility. On a race day, the polycarbonate may have several layers of this film.

Polycarbonate windshields have made a big difference in the world of racing, but they remain illegal to use on streetcars because they are easily damaged and don’t age well. Glass windshields are still the safer option for your standard car because they are hardier and can last in different climates year after year without needing much maintenance.