The very systems put into motor vehicles to ensure your safety could become safety hazards if not correctly dealt with following, for example, a windscreen replacement. One in five cars made worldwide now carries an Advanced Driver Assistance System that brakes for you in an emergency, warns of a forward collision, alerts you when you drift across a lane or reads and repeats traffic signs. Many also hold a following distance through adaptive cruise control, dip or raise headlights automatically, watch parking distances and in some models project augmented reality onto the windscreen.
What many drivers do not know is the camera behind that system sits at the top of the windscreen, and when the glass is replaced, the camera has to be recalibrated. The comparison used by those in the trade is a pair of bifocals dropped on the floor. If a lens shifts, everything you see changes. The camera works the same way.
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The technology relies on sensors to read the road ahead. Depending on the vehicle, these can include ultrasonic sensors, LiDAR, radar and mono, stereo or trifocal cameras. Most of the cameras sit against the inner surface of the windscreen.
Manufacturers require recalibration after any glass replacement or camera removal. The purpose is to teach the safety software the camera's new position once it is back on the glass. Because of normal differences in the shape of windscreens and camera brackets, the camera will point in a slightly different direction after a new windscreen is fitted.
If recalibration is skipped, the consequences are practical rather than theoretical. Functions can work incorrectly, stop working or lose accuracy. The system may sound false alarms or give no warning at all. It may fail to engage when it should, or engage when it should not, which raises the risk of a crash.
Insurers increasingly ask for proof of recalibration after a windscreen replacement, which brings legal and claim implications. A misalignment of one degree translates to an error of about 2,4 metres over 30 metres, a figure that matters at highway speed.
A further problem is a workshop diagnostic scan will not reveal a missing or inaccurate recalibration. According to PG Glass, such a scan may show existing fault codes, but it will not show that recalibration is needed or that it has been done. The car can appear fault-free while the assistance system is compromised. Only recalibration confirms that the cameras are working as intended, which makes this an unseen safety risk for owners of modern cars in South Africa.
The system depends on precise camera alignment. If the camera is not recalibrated after a windscreen replacement, it may keep using its original reference point, which is no longer correct because its position or orientation has changed. Safety features such as lane keep assist and autonomous emergency braking can then malfunction. In tests, mis-calibrated cameras have led to vehicles failing to stop in time under autonomous emergency braking and colliding, or leaving the lane where lane keep assist has failed.
Recalibration at a glass fitment centre involves two stages after installation, one static and one dynamic. The Automobile Association was taken through the process. The static stage resembles wheel alignment. Technicians place manufacturer-approved target boards in front of the vehicle at a set distance and height, aligned to the vehicle centre line, following the manufacturer's repair method. This has to be done on a level floor with adequate lighting.
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The static process then uses diagnostic tools plugged into the vehicle's on-board diagnostic port. The equipment connects to a remote diagnostic expert, who accesses the manufacturer's software and activates the calibration remotely. Because it is done over the air, it is quick and needs very little physical work.
Dynamic recalibration is done on the open road. It teaches the software the camera's new position or orientation while the vehicle is driven, using real road markings and surroundings. A diagnostic tool is needed to start it. Once the work is complete, the vehicle holds a permanent record of the recalibration and a certificate, which an insurer may ask for when a windscreen or accident claim is filed.
Eddie Irving, head of new markets at Belron, the parent company of PG Glass in South Africa, said the first ADAS recalibration anywhere in the world took place in 2014 and that more than five million vehicles were recalibrated globally after windscreen replacements in 2025 alone.
He said forward-facing cameras in the local car parc grew from about 2% in 2020 to 17% by the end of 2024, and that drivers need to understand why recalibration matters for safety. PG Glass, he said, has invested in calibration technology, technician training and operational capacity to provide the service.
Bobby Ramagwede, chief executive of the Automobile Association, said the AA has promoted the benefits of ADAS through NCAP and #SaferCarsForAfrica safety ratings for years. He described recalibration as the equivalent of a vehicle recall, calling it mandatory for the continued safe operation of a modern vehicle and, like a recall, a cost-free step that can save lives. The AA encourages owners to insist on certified recalibration with every windscreen replacement.
Ramagwede added that keeping an ADAS system at peak performance is an obvious step, pointing to a Dutch insurance study of 1-million cars between 2019 and 2021 which found up to 50% fewer accidents in vehicles with working front collision warning. A functioning system, he said, protects the driver, the passengers and other road users, including cyclists and pedestrians.
Colin Windell for Colin-on-Cars in association with
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