In winter, radar and camera systems can be blocked by snow, ice or slush long before you notice that something is wrong yourself. Then systems such as lane keeping assist, adaptive cruise control and emergency braking may reduce their function or switch off completely.

What you need to know

  • Snow and ice crust can block the radar even when the windscreen does not look especially bad.
  • Many cars give clear warnings when ADAS functions are temporarily unavailable.
  • You must be ready to drive fully manually when the systems drop out.

Typical situations

SituationWhat you should doCommon mistake
Snowfall and slushy roadsCheck the front, badge, bumper and windscreen around the camera during breaks.Continuing as normal even though the car warns about reduced function.
Cold morning with icingRemove ice carefully before starting the trip.Assuming the system will “wake up” by itself after a few kilometres.
Long motorway trip in wet winter weatherBe prepared for functions to drop out temporarily and drive fully manually.Using adaptive cruise control without monitoring when the sensor is partly blocked.

Common mistakes

  • Being surprised when driver assistance disappears in the middle of a trip.
  • Ignoring warnings about a blocked sensor or reduced visibility.
  • Forgetting that winter weather can change the sensor status several times during the same trip.

How to practice

Read this together with Cleaning sensors and cameras (ADAS) , Automatic emergency braking AEB and Lane keeping assist LKA and lane warnings .