When should I switch on my car headlights?

Modern cars have a variety of lighting systems aimed at keeping you safe in all manner of weather conditions – and not only when it’s dark. Thinking about the average car, you have lights to see where you’re going, lights for signalling the direction you’re headed, and lights to let others know you’re coming to a stop.

But there are other lights on modern cars that are equally important, and perhaps not as well understood. These include daytime running lights, fog lights, hazard lights and high-beam headlights.

In this advice article we aim to, umm, illuminate you as to how best to use your lights. We’ll let you know what each of the abovementioned lighting systems do, and when it’s best to switch on your lights to help keep you safe on the road.

It sounds like a simple question, but you’d be surprised how many people still drive in the dark without switching on their low-beam headlights. The short answer to the question is: when it gets dark enough that you need the low-beam headlights to see. But more crucially, it’s also when you feel you need to be seen.

Think about a dim, drizzly day where there might be enough natural light to see where you’re going, but not enough to see a considerable distance ahead. Chances are that if you can’t see oncoming cars at a distance of more than 200 metres, then they can’t see you either. This is especially important if your car is a similar colour to the road surface.

It’s also a good idea to switch your low-beam headlights on at sunrise and sunset. These in-between times, where long shadows can create a flickering sensation between trees and buildings, can obscure your car from the view of others. Again, you might have enough natural light to see where you’re going, but a well-lit car may just help others to see you a little sooner.

As the name might suggest, park lights (or marker lights, as they’re sometimes known) are to be used when you’re parked. Park lights are typically represented by an accompanying green symbol on the instrument panel. When the park lights are in operation, a low wattage globe shines at both sides of the front (headlights) and rear (tail-lights) of your car.

Of course, this doesn’t mean you should leave them on when you’re parked overnight (as this will result in a flat battery). Instead, think of the park lights as a temporary means of drawing attention to your car when parked in a situation that might require it to be seen, such as in a loading zone or other temporary parking space.

If your car isn’t fitted with daytime running lights, you might also consider driving with your parking lights switched on during daytime hours.

Daytime running lights  (DRLs) are located only at the front of the vehicle and are either a standalone light or incorporated element of the headlight that is in operation whenever the vehicle is running.

The DRLs are designed so that your vehicle may more readily be seen by other drivers, especially if it’s a dull or drizzly day. Depending on the vehicle, these may be a standard candescent globe or an LED array (again, either as a standalone light or one that’s incorporated as an element of the headlight).

Unlike park or headlights, DRLs may not be switched off when the car is running. As such there is no symbol inside the car to indicate that the DRLs are operable. It’s important to understand that the DRLs will extinguish when the engine is switched off.

High-beam headlights are the brighter element of your car’s main headlight beam. They are differentiated from the regular, low-beam headlight by a headlight icon with horizontal beams, and are usually indicated as being operable by an accompanying blue symbol on the instrument panel.

Depending on where you live, there are different laws surrounding the use of your headlights’ high-beam (check your state government’s road department website for more details). Typically, these laws aim to prevent high-beam headlights ‘dazzling’ the driver of an oncoming vehicle – or the driver of a vehicle you’re following from behind. The typical guideline is to dip your headlights at a distance of 200m or more if safe to do so.

When there is no other vehicle close by, it is a good idea to use your high-beam headlights as required. High-beam headlights may only be used at night, and should not be ‘flashed’ to signal other drivers (this is illegal in some states and territories). In most parts of Australia, high-beam headlights may be used in a built-up area, but are generally most effective on highways, freeways and country roads where street lighting isn’t present.

Many new cars have automatic high-beam headlights that dip as soon as they register vehicles up ahead, but these can all be overridden by the driver, so it's important to use your own discretion and err on the side of caution and courtesy to others.

When coming to the crest of a hill, for example, if you can see that another vehicle is approaching from the other side, then dip early. Truck drivers could be temporarily blinded by your car's lights blasting into their cab before the car detects their headlights a moment later.

The name of the lights here should give this one away. Fog lights, not surprisingly, are to be used when fog is present. They may also be used in ‘inclement weather conditions’ according to some state and territory rules, including heavy rain, dust and smoke.

At the front of the car, fog lights are typically positioned in the lower section of the bumper, while at the rear are either set as a separate light within the bumper or integrated as part of the tail-light assembly. The fog light switch is indicated by an icon similar to that of the headlight, but with a squiggly line through the light ‘beam’. An accompanying image is usually displayed on the instrument panel.

Although it seems to be a trend among drivers to operate fog lights in clear conditions, we should point out that in most Australian states and territories it is an offence to do so.

Most states enforce a fine with associated demerit points for disobeying this rule.

Indicators, turn signals or blinkers are all the same thing. They should be used to ‘indicate’ to others that you are about to change lanes or make a turn.

The law around the time that indicators should be used prior to making a turn is vague, and open to interpretation. In Victoria, for example, it states that “you must always use your indicators for long enough to warn others that you are making a turn, changing lanes or changing direction”.

The indicator wand (or stalk) is located on the side of the steering column in most cars, with an arrow icon pointing left or right to show the direction for which the indicators will illuminate. A matching icon in green is usually found on the instrument panel, while the accompanying external lights will flash orange, usually at a rate of up to two times a second.

Hazard lights, or four-way flashers, are an extension of your car’s indicators. These are activated by a separate switch, usually represented by a triangular icon as pictured. When activated, the hazard lights will flash all of your car’s indicators simultaneously.

The use of hazard lights, again as the name suggests, is to indicate to others that your car poses a potential hazard. This may be that you’ve had a mechanical breakdown, a flat tyre or have been involved in an accident. Simply, hazard lights serve to warn others that your car is stopped in a position they may not expect. It allows other drivers enough time to take appropriate action to avoid hitting your vehicle.

If you find yourself stopped in an unmarked parking bay – for whatever reason – it’s a good idea to activate your hazard lights. However, it is an offence to use your hazard lights to “invent” a parking space while you run into the shops, for example, or drop the kids off at school. Again, a fine and demerit points may be applied.

Dashboard illumination includes your instrument panel lights, and the tell-tale lights used to show where various switches and secondary functions (like the climate control) are located. In most modern cars, this also extends to the infotainment screen.

While many modern vehicles will dim these lights in conjunction with headlight use, there are others that will need to be dimmed separately. This is typically done by a small dial (or rheostat) on the dashboard or via a menu setting within the instrument panel itself. Your owner’s manual will let you know how to adjust your car’s instrument panel lights.

Why do you need to adjust your instrument panel lights? In a word it’s about glare. If the interior lights of your car are too bright, it diminishes your eyes’ ability to see into the darkness outside. As a guide, you should dim your interior lights to the lowest point comfortable for easy viewing. Spend some time finding a setting that works best for you while your car is still safely parked.

It should be pretty obvious if one or more of your vehicle’s lights aren’t working. But in some cases, you may need the help of a friend or family member to check. In the case of the indicators, you may notice that the flash rate increases or the indicator remains steadily lit if one of the globes is ‘blown’.

If you’re unclear about the operation of any of your vehicle’s lights, please consult your owner’s manual. It is a crucial legal requirement that all your vehicle’s lights are clean and operable every time you drive. Fines and demerit points may be applied for non-compliance.

Always check that all your vehicle’s lights are adjusted in accordance with the manufacturer’s specifications. If you’re unsure of how to do this yourself, contact your dealership or mechanic for further advice.

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