Your safety systems look through your windshield. Replace the glass and they have to be re-aimed.

Your safety systems look through your windshield. Replace the glass and they have to be re-aimed.

Advanced Driver Assistance Systems are the features that watch the road for you: lane departure warning, lane keep assist, automatic emergency braking, forward collision warning, adaptive cruise control, and traffic sign recognition. On most vehicles built in the last decade, the camera that drives those systems is mounted to the windshield itself, behind the rearview mirror.

That camera is aimed to a tolerance measured in fractions of a degree. Take the glass out and put new glass in and the camera has moved — even a millimeter of difference in bracket position translates to being off by feet at the distance where the system needs to make a braking decision.

An uncalibrated system doesn’t usually throw a warning light. It just quietly measures the world incorrectly. That means automatic braking that triggers late, or lane keep assist that steers toward the wrong side of the line.

If your vehicle has ADAS and the windshield is replaced, calibration is part of the job. Any shop that tells you otherwise is cutting a corner you’ll never see.

We own the calibration equipment and targets, so we handle it on the same visit as your replacement. You don’t get handed a dealership appointment and a second bill.

Static calibration uses precision targets set at manufacturer-specified distances and heights on a level surface.

Dynamic calibration requires driving the vehicle at a set speed on well-marked roads while the system relearns. Some vehicles need one, some need both — the manufacturer’s procedure decides, not us.

Calibration is part of a properly completed windshield replacement, and carriers generally cover it as part of the claim. We bill it directly along with the glass.