What must you do if glass falls on to the road from your vehicle? Check all that apply. What must you do if glass falls on to the road from your vehicle? Check all that apply.

  • A. Nothing is required - council road workers will remove it in due course

  • B. Stop and remove the glass yourself if it can be done quickly and safely

  • C. Tell the police if you can't remove it because you are physically incapacitated

  •  
    The correct answer is B, C
     
    Correct. Broken glass can puncture tyres, which is particularly dangerous for cyclists and motorcyclists. It's your responsibility to see it's removed.
     
 
 
 

If glass falls on to the road from your vehicle you must stop and remove the glass yourself if it can be done quickly and safely, or tell the police if you can't remove it because you are physically incapacitated.

What is automotive glass?

Even though automotive glass looks similar to regular glass, it’s quite different. It’s manufactured to work within the vehicle’s construction to provide protection and added rigidity. If you look closely, you can see some differences. For example, the glass in your rear window will have wires running through it through which a current is passed that heats the glass to evaporate condensation. On some vehicles, the front window has an antenna embedded in it for the radio.

What are the types of automotive glass?

There are three main areas where different types of glass might be used on your vehicle.

Laminated glass

By law a windscreen must be made of laminated glass and this is usually a sandwich of two 2.1mm layers of glass with a 0.8mm sheet polyvinyl butyral (PVB) in the middle. They are fused together to form a strong, curved sheet which won’t shatter into pieces on impact. The film holds the glass together in one sheet, helping prevent shards of glass enter the cabin as they stick to the film. As the plastic sheet is stretchy, it helps absorb any impact, e.g. a deer hitting the windscreen.

The PVB filters out the majority of the sun’s UV A and UV B rays (95% or more), helping protect occupants from sunburn as it's the equivalent of wearing factor 50 sun screen. As the glass is so strong, it helps with structural rigidity. In a rollover crash it will help prevent the roof from buckling downwards.

Tempered glass

Tempered glass is rapidly heated and cooled several times. If broken, it shatters into lots of small pieces that aren’t as sharp or likely to cause damage to vehicle occupants in an accident. Tempered glass is strong enough to withstand fairly strong impacts and closing the door hard. It’s also safer to have tempered glass on side windows if you end up in a situation such as the vehicle being underwater or in an accident where the doors can’t be opened, because the glass can be broken by kicking it.

Tempered glass does not block UV rays as well as laminated glass unless it's been specifically UV-treated. Typical SPF protection is around 20 in glass that is not specifically treated, and around 45 in glass that is. Tinting a vehicle's windows increases the SPF.

Some fleet vehicle operators request laminated glass all around for vehicles that contain high-value equipment.