Windscreen Law & Regulations FAQs

Can you drive a car/ vehicle with a cracked windscreen?

With increasingly busy lifestyles, many overlook the importance of having a windscreen chip or crack fixed. Although it is clearly very dangerous, is driving with a chipped windscreen breaking the law?

Driving a motor vehicle in what is considered a dangerous condition e.g. with a chipped or cracked windscreen is an offence under section 40 of the Road Traffic Act. As such, if you were caught driving in this condition, you could receive 3 penalty points on your driving licence and a fine. If the case is taken to court, you may find yourself receiving a larger fine or even disqualification if you have previous convictions.

Finally, a windscreen with a chip or crack could cause your vehicle to fail its MOT, so it’s important to have the problem fixed before it escalates. Take a look at our guide to find out whether your windscreen needs to be repaired or replaced.

Is there a difference in rules for windscreens for different vehicle types?

Yes. When it comes to windscreen repairs and maintenance, HGV vehicles, such as trucks and lorries, need their own specialist care. The large size of HGV windscreens means that there are different zones in which cracks and chips can fall into. ‘Zone B’ covers the majority of a vehicle’s windscreen which does not fall into the driver’s line of vision. If chips and cracks fall within this zone, a repair is more likely to be needed than a full replacement as it is considered less of a safety risk.

However, if the damage is obscuring the driver’s view then it falls into ‘zone A’, meaning that a replacement is required. Whilst this is similar to cars, for HGVs cracks of up to 150mm/15cm in length can be repaired, as opposed to cars where the crack must be smaller than £2 coin.

For larger fleet vehicles – such as buses, coaches and agricultural vehicles – certain marks or blemishes would not even require repairs, let alone replacement. For example, a number of light scratches spread over a large area of the windscreen will not need immediate attention. However, a collection of heavy scratches may be caused by a problem with the windscreen wipers which may require separate attention.

How and where should windscreen repairs or replacements be carried out?

When it comes to repairing or replacing a windscreen, it’s important that the job meets the safety and quality standards in line with UK MOT rules for windscreens. Windscreen repairs need to meet British standard BS AU242a:1998 to ensure they are tested to the same standards as original windscreens when it comes to strength, performance and weather resistance.

Replacement glass must be fitted to an OEM (original equipment manufacturer) standard to ensure the replacement windscreen is fitted to the exact same guidelines and safety standards as the day it was made.

Are there any laws on how much of your windscreen you need to see out of?

Even the smallest windscreen chip in the driver’s line of vision could cause a vehicle to fail its MOT test. Although the placement of stickers and GPS devices on the front windscreen is not illegal, The Road Vehicles (Construction and Use) Regulations 1986 states that: “all glass fitted to a motor vehicle shall be maintained in such condition that it does not obscure the vision of the driver while the vehicle is being driven on the road.”

The Highway Code also states that “windscreens and windows MUST be kept clean and free from obstructions to vision”. Whilst this is not official legislation and will not immediately result in a prosecution, The Highway Code can be used as evidence in a court case under the Road Traffic Act.

Similarly, whilst it isn’t illegal to obscure the rear windscreen – either due to a sticker or a large load – the driver may be prosecuted if the vehicle does not meet regulation 33 of The Road Vehicles (Construction and Use) Regulations 1986. It states that at least one fully functional mirror should be fitted on the exterior of the vehicle if the view through the rear window is obscured.