Know the road rules - using headlights

In many daytime situations, driving with your vehicle’s headlights on can improve the likelihood of being seen by other road users.

Cars driving along a coastal road at dusk

In many daytime situations, driving with your vehicle’s headlights on can improve the likelihood of being seen by other road users.

When should your headlights be on?

Roads and Maritime Services says your headlights must be on when:

Driving between sunset and sunrise.
At any other time when there is not enough daylight to be able to see a person wearing dark clothing at a distance of 100 metres.

Other rules about headlights

Dazzling lights

Do not use or allow any light fitted to your vehicle to dazzle another road user. Avoid looking at the headlights of oncoming vehicles. If you are dazzled by glaring or high-beam lights, look to the left side of the road and drive to the left of your lane, slow down or pull over until your eyes recover.

High beam

To see further ahead, use your headlights on high beam on any road, even if there are street lights. You must dip your headlights to low beam:

When a vehicle coming toward you is within 200 metres.
When driving 200 metres or less behind another vehicle.
When you overtake another vehicle, you may briefly flash high beam immediately before starting the overtaking manoeuvre.

Fog lights

Front and rear fog lights must only be used in fog or rain, or when conditions such as smoke and dust limit your vision. It is a legal requirement that once conditions improve and you can see more clearly, the front and rear fog lights are switched off. If your vehicle is not fitted with fog lights, use your headlights during the day in these adverse conditions.

Daytime running lights (DRL)

A daytime running light is a lighting device on the front of a vehicle or bicycle, automatically switched on when the vehicle is moving forward, emitting white, yellow, or amber light to increase the conspicuity of the vehicle during daylight conditions.

Are daytime running lights actually beneficial?

The NRMA presented a submission to the State Government way back in 2009 that called for the use of low beam headlights during the day by drivers (as is the case with motorcyclists) until DRLs become standard.

Our submission included estimates that DRLs could prevent 3-11 per cent of non-pedestrian fatal crashes, 4-11 per cent of non-pedestrian non-fatal incidents and 4-12 per cent of all pedestrian impacts.

The reason why we prefer DRLs over low beams is that the former are more effective in terms of making vehicles conspicuous to other road users while being more efficient – headlight use slightly increases fuel consumption – and also more reliable, as they turn on and off automatically whereas headlights are operated by the driver.

There is also the common situation where dashboard lighting automatically dims when headlights are turned on as the car ‘assumes’ it is operating during the night, which can make the speedometer and other vital indicators more difficult to view during the day.

Objections to DRLs are usually based on encounters with vehicles that have their lights poorly fitted or adjusted so that the beam shines in the wrong direction and is distracting to oncoming traffic, but factory-fitted units and correctly-maintained examples will not do this.

In contrast, the support for use of DRLs – which have been mandatory in new cars sold in Europe since 2011 – is coming in literally from around the world.

A study by the National Highway Traffic Safety Administration in the US found a 7 per cent reduction in multiple-party daytime crashes, but this was restricted to daylight hours and didn’t take into account low-light conditions at dawn and dusk where DRLs are most effective.

In contrast, research by the Minnesota Department of Transport reveals a remarkable 73 per cent greater likelihood of crashes and a 48 per cent higher risk of fatality for vehicles without DRLs, although this state is on the Canadian border and has extended low light periods in winter (which is why Scandinavian nations mandated DRLs way back in 1977).

An evaluation by the French National Institute for Transport and Safety Research showed a 58 per cent reduction in fatal crashes and serious injury incidents on major roads when vehicles featured DRLs, although there was no reduction in less serious crashes or collisions on minor roads.

And a fleet study of 80 vehicles in Perth – the only study of its kind in Australia – found that DRL-fitted vehicles took more than five times longer than non-DRL-fitted vehicles to be involved in daytime collisions.

The data variability adds credence to the conclusion in a report by the Australian Transport Safety Bureau:

“It is clear from the body of evidence that there is high probability that DRL would reduce daytime multiple-party crashes in Australia. However, it is not clear by how much they would be reduced.”

But even with the variability in the findings, the NRMA still believes Members and all road users who are wary of DRLs should take a fresh look at the technology in the name of safety.

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