Ask an expert


Can you please tell me what the story is with extra bright headlights (possibly two sets) on cars.

On several occasions we have travelled at night with cars immediately behind us and find it is harder to deal with than a car that has its lights on full beam.

Are these lights legal and why do only some cars have them?


From the "Ask Jack" archives - 14 December, 2010


Vehicles that give off a very bright light will probably have High-Intensity Discharge (HID) headlights fitted. These lights have gas filled bulbs rather than the traditional filament type and project a very bright beam. They should not create excessive 'dazzle' however when following behind or facing on-coming traffic.

The general rules around the use of headlights are as follows;

Main beam headlights are designed for the open road and are to be used when there are no other vehicles in front or coming toward you.

A driver must switch to dipped beam as soon as they notice other vehicles ahead to avoid dazzling them.

All vehicles except motorcycles may have up to four main beam headlamps. For example, if your vehicle has two main beam headlamps you may add two more, but if it already has four main headlamps you may not fit any extra.

Sometimes it is best to simply let cars pass at the safest opportunity if their lights are not dipped or not aimed correctly and are shining directly into your vehicle.

You sometimes get those drivers who have no consideration for others and either wire their lights illegally or do not dip the lights when following or facing other traffic.

Lights are checked for alignment at time of a Warrant of Fitness check so in theory you should not get light shining directly into your vehicle if following traffic have their headlamps dipped and aligned correctly.