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Explain car lights to me
September 3, 2012 9:38 AM   Subscribe

Which car lights should I use when? On different cars: How do I select them? How do I know which ones are on?

This seems like a crazy thing to not be able to know or figure out on my own, but, honestly, I have spent a lot of time googling this, and have somehow not been able to figure this out:

I am a pretty infrequent and not-so-experienced driver of cars. When I drive, it's usually a rental car, or car-share car, so I drive lots of different cars, with different controls, and different dashboards.

I am confused about a number of things about car lights. From what I undertand, cars have regular headlights, high-beams, daytime running lights, sometimes fog lights (and maybe others I do not know about).

What I want to know is:

1) What lights should I be using in what situations?
2) How do I typically turn the lights on/off and choose which light(s) to use?
3) How can I tell, from the dashboard, what lights are in use? Are there standard symbols?

I have googled all over for a page that explains all this, but have somehow not been able to find anything.

If it matters - I am in Canada, and sometimes drive here, sometimes in the US.
posted by ManInSuit to Travel & Transportation (28 answers total) 2 users marked this as a favorite
 
US driver here. In simplest terms, use the lights when they help you drive. IE, headlights at night, both so you can see where you're going and other cars can see you coming.

Use the highbeams when you are driving on a road at night with no oncoming traffic - this will increase the distance you can see ahead of you. Switch to lowbeams when you see traffic coming so as not to blind the oncoming driver.

Where I drive it is the law that you must also have your headlights on when your windshield wipers are being used, day or night. Using your headlights during the day, raining or not, also helps improve your visibility to other drivers so it's not a bad idea but not necessary.

I've never driven a car with foglights but the way I understand it is this - dense fog will reflect your headlights back at you, making it even hard to see when you have your headlights on. The foglights are angled so as to provide some penetration of the fog and to make you more visible to other drivers, without reflecting back at you.

I never use the parking lights unless I want to be visible to others without having my headlights on, usually at very low speeds. This comes in handy when you are driving up to someone who does not have headlights or is not in a car, and you don't want to blind them, or maybe if you are pulling into a driveway when the people inside are sleeping and you don't want to disturb them.

Your question does not ask about turn signals, so I assume you understand that.

Really, all you need to know is: headlights at night and when it's raining, lowbeams when there is oncoming traffic.

Have you asked your local DMV (department of motor vehicles) or whoever licenses drivers where you live for a driving manual?

Finally - in the US you can get discounts on your auto insurance for taking driving classes - this might be a good move for you and a way to get more answers.
posted by natteringnabob at 9:51 AM on September 3, 2012 [1 favorite]


American here, but we have almost the same rules for this sort of thing...

You use blinkers when you turn. You use headlights at night (and if you want to use the high beams for more light, you go back to regular headlights when behind or approaching another car). You use emergency flashers when you have reason to believe that you can't continue traveling at the posted speed limit (you wouldn't normally use them when pulling over on a residential street, but in a 70kph+ zone or when you have an actual vehicle failure, you should use them).

Brakes and reverse lights will always come on and turn off automatically for you.

Some places have rules about using your headlights in the rain - If you have daytime running lights ("always-on" headlights), you don't need to worry about that.

You generally shouldn't have any interior lights on at night while actually in motion, but not such a big deal if you have a passenger quickly taking a peek at a map (and honestly, the normal console lights in most cars adjust from "off" to "I can only see the reflection of my face in the windshield", so one little map light won't fall far outside the normal range of preferences).


For telling which ones you have on - Blinkers have a light on the console that blinks (and usually makes a clicky noise). Headlights don't always have a light, but high beams usually have a little blue light that looks kinda like a bullet with motion-lines behind it (presumably they mean it to look like some sort of a parabolic reflector with light coming out, but I think my description a bit more accurate). Emergency flashers almost always use your normal blinkers but will flash both sides in sync (and still make the clicky sound). Other lights usually have no indicators (other than the light itself) to let you know you have it on.


For turning them on - That varies a lot by car. Blinkers commonly work from the left lever off the steering column, either up/down or twist forward/backward. Headlights often have a knob on the left dash with multiple settings, or one of the many toggles on the levers coming off the steering column. High beams often work like blinkers, except forward/backward or in/out on the left lever. Emergency flashers almost always have a little mushroom-like button somewhere, but I've seen them placed just about everywhere within reach of the driver (including under the dash). Reverse lights depend on your gear, and brake lights come on when you start touching the brake (so if you "ride" the brake with even the lightest touch, you effectively make brake lights useless by keeping them always on).


On preview, natteringnabob said many of the same things I did, but I'll still post this just in case the different perspective and wording helps you out. :)
posted by pla at 9:55 AM on September 3, 2012


Adding on to natteringnabob's answer, you don't have to worry about daytime running lights -- they are a sort of low-level headlight that is on whenever the car is running. You can't control them, so you don't have to think about them. They are designed to make vehicles easier to see even during the day, especially on cloudy or overcast days.

I believe they are mandatory on all vehicles in Canada, and increasingly common in the US -- if you drive on a cloudy day and look in the rear-view mirror and notice that all cars seem to have a faint light on, those are the daytime running lights.
posted by andrewesque at 9:56 AM on September 3, 2012


Cars that have daytime running lights usually turn them on automatically when the key is turned in the ignition. Daytime running lights should not be confused with the amber parking lights: daytime running lights include the headlamps, parking lights do not include the headlamps. You should not drive around with just parking lights on. Parking lights are usually the first stop on the knob that turns the headlamps on.

Turn regular headlights on a) at dusk through the night or, b) when it is raining or, c) any time during the day where you feel like being more visible to oncoming traffic or, d) when instructed to do so by highway signage.

Turn high beams on only when there is no oncoming traffic. High beams are to temporarily illuminate roads with insufficient street lighting.

Turn fog lights on when visibility is poor due to fog as a supplement to your regular headlights. Don't use high beams in fog as they will just reflect back and cause whiteout/glare.
posted by jamaro at 9:59 AM on September 3, 2012


1) What lights should I be using in what situations?

Daytime running lights: You have no option to turn these off, so don't worry about it.

Parking lamps (may be integrated with turn signals or separate yellow-white or orange lamps): In parking structures, when idling, or in cloudy/misting conditions. They will come on with the intermediate switch setting between headlamps and no lights and will stay on when you switch to headlamps.

Headlamps (low beams): Night, close to dawn/dusk, precipitation.

Headlamps (high beams): Dark night conditions with no oncoming, parallel, or nearby perpendicular traffic.

Fog lamps: Almost never. Most "fog lamps" on US-spec cars are cosmetic anyway and are aligned so that they are no help in fog.

If you live in a foggy region of the world, you may well have effective fog lamps (to be used in foggy conditions). You may also have rear fog lamps (if you're using an EU-spec car) which are bright rear-facing red lamps that operate independently of the brake indicators, so you can use these under foggy conditions too.

Roof- or brush-guard-mounted "driving lights": Never, except off-road.

2) How do I typically turn the lights on/off and choose which light(s) to use?

Consult the owner's manual. Many newer cars have automatic light selection based on detecting ambient light so if applicable you will want to read the blurb on this system too.

3) How can I tell, from the dashboard, what lights are in use? Are there standard symbols?

Parking lamps may have a green dashboard indicator shaped like an old-style turn signal (think 1995 Ford Taurus), but sometimes there is no indicator.

Low beams typically have no dashboard indicator.

High beams will have a blue dashboard indicator that looks like a lit lamp shining left or right.

Fog lamps may have green indicators (sometimes separate for front and rear fog lamps) with a lamp shining down-left or down-right.
posted by Inspector.Gadget at 10:01 AM on September 3, 2012


Thanks! These replies are are all *very* helpful. Maybe I can clarify what I think is my principle confusion: I'll be driving at night, in a car I have not been in before, and I can't figure out how to tell whether the lights or on, or if so, which lights are on (eg: do I think the lights are on, when really it's just the DRL's? Am I driving with high-beams when I shouldn't be?)

This is compounded by the fact that both the controls and dashboard indicators use symbols whose meaning is not at all obvious to me. Pla's advice that "high beams usually have a little blue light that looks kinda like a bullet with motion-lines behind it". Is very useful. I sorta figured that one, but was not 100% sure. Are there other reasonably-standard symbols, either on the controls themselves or on the dashboard? I am similarly baffled by whether there is any correlation between whether the dashboard is illuminated, and whether the headlights are on.
posted by ManInSuit at 10:06 AM on September 3, 2012


Oh! Inspector.Gadget's reply answered some of the q's I justed posted (should have previewed). Here, maybe, is a key question:

Low beams typically have no dashboard indicator.

So, then, how can I be sure I have them on when I'm driving, and am not just driving with my DRL's on? (I guess this would look different on the road, but to an inexperienced driver, driving on a lighted highway, I'm not sure I can tell which is which...)
posted by ManInSuit at 10:09 AM on September 3, 2012


I can't figure out how to tell whether the lights or on, or if so, which lights are on

Honestly, the easiest way to tell is to do a quick pre-flight on the car's controls before you leave the first parking lot: turn on the ignition, leave the car's gear in park, push or turn a control and get out of the car to see what is happening up front/back. I do this with every rental, even though I've been driving for nearly 35 years.
posted by jamaro at 10:10 AM on September 3, 2012 [4 favorites]


So, then, how can I be sure I have them on when I'm driving, and am not just driving with my DRL's on?

Check the position of the switch before you drive.

Alternately, if you're reasonably distant from another car, try turning your brights on momentarily. If they stay on, you're using your lowbeams and can move back to them by turning the brights off. If not, you need to turn your lowbeams on (remember to flip the highbeam lever back into off position lest you wind up the opposite problem).
posted by Inspector.Gadget at 10:11 AM on September 3, 2012


Can you see the road well when you are in the dark? That's how I've found that answer out in a strange rental car--figured this out on the freeway, which is a bad idea. If you can see well in front of you, the low beams/daytime lights are automatically on.

I highly recommend reading the car manual (assuming it's in the glovebox) before you start out with a new-to-you car. That way you can find these things out before you have to figure them out on the road. Sit in the car with the lights on and take longer to leave if you have to.
posted by jenfullmoon at 10:12 AM on September 3, 2012


So, then, how can I be sure I have them on when I'm driving, and am not just driving with my DRL's on?

DRLs come in two varieties, IME - normal, regular headlights that always stay on (so you don't need to worry about whether or not you have your headlights on), and a very dim front-facing light that in no way functions as a good source of light at night (ie, they don't really help you see the road). If you drive in a brightly-lit city, you may not notice the difference. If you drive anywhere without street lights, however, you'll have absolutely no uncertainty whether or not you have proper headlights on. :)

Also, regarding the use of high beams, particularly in rural areas - You probably won't need them to see the road just fine, but they focus higher and wider than your headlights - Meaning they can give you an extra second or two to not hit something like a deer. You should pretty much always use your high beams when not around other cars.
posted by pla at 10:17 AM on September 3, 2012


Another situation where you want to turn your headlights on in the daytime is when going through a tunnel: The tunnel may be adequately lit, but the irises of the driver in front of you that just exited the tunnel into the bright daylight have already contracted, making your car in their rear view mirror practically invisible against the relative darkness of the tunel. Overtaking near the tunnel exit with your headlights turned off is a great way to cause an accident.
posted by Dr Dracator at 10:22 AM on September 3, 2012


DRLs come in two varieties, IME - normal, regular headlights that always stay on (so you don't need to worry about whether or not you have your headlights on), and a very dim front-facing light that in no way functions as a good source of light at night (ie, they don't really help you see the road).

To add on to this, some normal automatic lighting systems (Volvo & BMW come to mind) seem to default to always leaving the full complement of lights (discrete DRLS/parking lamps/low-beams) on, even at noon in the summer.

Some cars (I'm thinking of Toyotas here) put a secondary dim bulb inside the high-beam enclosure to act as a daytime running light. This has the unfortunate side effect of shining at least some light onto reflective highway signs etc., which can fool unfamiliar drivers into thinking that their headlights are on; take a moment to be sure that this isn't happening to you the first time you drive a given car at night.
posted by Inspector.Gadget at 10:22 AM on September 3, 2012


Whenever I drive, I make sure I turn on the (regular, low-beam) headlights before I start moving. I don't drive without headlights on. If I rent a car, I do the kind of preflight that jamaro mentions, turning them on with the car in park and getting out of the car to make sure they're on. (And of course, I'm extra careful to make sure they turn off when I get out and lock the car later.)

Do a search for "driving with headlights on all the time" and you'll see that the statistics support my decision; doing so has been shown to reduce the likelihood of being in a collision by up to 32 percent.
posted by limeonaire at 10:27 AM on September 3, 2012 [1 favorite]


Low beams usually have no separate dashboard indicator like high beams do, but when ANY lights are on, the dashboard interior lights themselves will be on. (I.e., if you can see your speedometer at night because it's lit up, your headlights are on.) Many areas have laws requiring your lights (this means the low beams) to be on whenever you have your windshield wipers on; it's also a good idea in any low-light periods, like early dawn or dusk, or heavily-overcast days.

When it comes to high beams, you will very, very rarely need them in urban areas such as in cities or areas with streetlights. Do NOT use high beams during fog or other high humidity times: doing so will actually REDUCE your ability to see, because the high beams will reflect off the water droplets in the air, rather than illuminating the street. This kind of foggy/high humidity situation would, on the other hand, be the only time using the fog lights is useful --- they aim even lower than your normal low beam lights, and so give that extra illumination of the roadway that WILL help you.

Please, if you DO turn on your high beams, TURN THEM OFF IF ANY OTHER VEHICLES ARE VISIBLE AHEAD OF YOU --- it doesn't matter whether those other vehicles are ahead of you and going the same direction, or coming towards you, high beams blind other drivers.

Don't worry about the so-called parking lights at all.
posted by easily confused at 10:31 AM on September 3, 2012 [1 favorite]


If you can read the instruments on the dash in the car, then at least you know your parking lights are on. They illuminate or back light when you turn on the exterior lights.

In a rental, first thing I usually do (after figuring out how to release the parking brake) is aim the headlights at a wall and fiddle with the controls until I can tell how to turn them on and off. Some rentals have been tricky with the auto-sensing-darkness thing. If I can't figure it out, I just drive it to the car issue guy and ask.

Really, the only thing you can screw up without noticing it yourself is having the high beams on by accident. If everyone traveling the opposite direction on the road is flashing their high-beams at you, you might want to consider that.
posted by ctmf at 10:37 AM on September 3, 2012


but when ANY lights are on, the dashboard interior lights themselves will be on.

Just to maintain the randomness, this is not by any means a sure fire rule. I have two cars that'd fail that rule in my garage. Also, it totally depends on how the daytime running lights are wired on the car for Canadian regulations. Often, however, if the dash lights are on the whole time, then there is an indicator that the headlights are on (with an additional blue 'main beam' light).

Really, the advice about when and where seems to be ok. You can run your full lights all the time, day or night, but absolutely should run them whenever it is dark, dusk or raining/foggy for safety. Main/full beams should only be when you have no-one in front of you (Facing or moving away from you) because of the dazzling aspect.

Fog lights help you see when it is foggy.

Sidelights are only for marking your vehicle when parked.

The only 100% safe way to check what lights you have on is to look at the switch, really, especially in an unfamiliar car.
posted by Brockles at 11:17 AM on September 3, 2012


The only 100% safe way to check what lights you have on is to look at the switch, really, especially in an unfamiliar car.

Even more naive question, then - what should I be looking for on the switch? Lots of times, it seems to me, the switches are labelled with a set of not-obvious-to-me symbols.
posted by ManInSuit at 11:45 AM on September 3, 2012


They're nearly all marked with a '0' for off, and just turn them all the way on for headlights.
posted by Brockles at 11:59 AM on September 3, 2012


what should I be looking for on the switch?
Around the switch you might find the symbols for the different types of light. Some functions might require pulling the switch instead of turning it. It should be all in the manual.

Near the top of this picture are the symbols how the might appear in a European car. From left to right: parking light (one side only), parking light (left and right), daytime running lights, headlights (low beam), headlights (high beam), fog light (front), rear fog light.
posted by mirage pine at 12:03 PM on September 3, 2012


To answer your third question here's a gallery of dash lights, the section titled "Lighting Indicators and Symbols" shows common symbols displayed on the dash indicating the mode and status of the lighting system.
posted by jackmakrl at 12:27 PM on September 3, 2012


Yeah, this is way too much thought. Turn on your normal (low beam) lights whenever you drive. Turn them off whenever you park. If you are having trouble seeing for any reason (fog, it is too dark, etc.) then slow down. This is one simple headlight rule that is safe and acceptable in all the situations you're likely to find yourself in.

Usually your low beams are turned on by twisting the headlight control (either on the dash or on a wand on the steering column) as far as possible. Turn them off by twisting as far as possible the other way. Don't disturb any of the other controls while you're doing this.

(High beams and fog lights are useful, but not necessary and using them incorrectly messes up other drivers. Unless you're regularly driving in the country you can just slow down when the conditions are poor.)
posted by anaelith at 12:33 PM on September 3, 2012


Most newer cars have DRLs, which are basically headlights that stay on all the time. Sometimes they're dimmer than the normal lights, sometimes they're entirely different lamps. If you want your lights on for driving in the dark or rain (which you do), you will probably have to turn something extra on, at least in order to see all your dashboard stuff. But every car should have a manual and it wouldn't take too long to find the index and then look up what the stuff means.
posted by masquesoporfavor at 2:05 PM on September 3, 2012


Most sedans will have all or most of the lights on a stalk coming off the left side of the steering column. Up for the right turn signal and down for left (I know everyone knows this, just covering my bases). Twist the end to turn on the lights. If it doesn't have an auto setting, one click gets you the parking lights (same amber bulbs as the turn signals), two clicks gets you the normal headlights. When the headlights are on, pull the stalk back to flash the high beams, push it forward to turn them on. This is not at all standard though. Some have you pull back a little to flash the high beams, pull back 'till it clicks to turn them on and pull again to turn them off. Some cars have a rotary switch on the left side of the dash (forward from the left stalk) to turn on the lights. Consult the manual and play with it to be sure.

Some cars will also have an inner ring for fog lights (if the car has them).

Dash lights will like up when the parking lights or headlights are on and you'll get a (usually blue) indicator when the high beams are on.

I use the parking lights when it's dark but I don't need to see and I don't want to blind people. Usually just the last few feet as I pull into a parking spot facing a restaurant or in a parking garage.

Fog lights can only be turned on when the headlights or high beams are on and should be used in the fog (obviously), rain, or snow (or any other time you feel like they're helping you see better).

As others have said, the high beams are only for lonely highways at night with no oncoming traffic in non-residential areas.

Once you've been in enough cars, you won't need to look it up in the manual every time. I worked at a car dealership in my late teens and ever since then, I can get into just about any car and figure out all the controls in pretty short order.
posted by VTX at 2:57 PM on September 3, 2012


pla: "Some places have rules about using your headlights in the rain - If you have daytime running lights ("always-on" headlights), you don't need to worry about that."

Not true. First, many vehicles use the parking/signal lamps as DRLs, not headlights. Secondly, the vast majority of the remainder of vehicles with DRLs use the high beams at low power, so it doesn't actually meet the letter of the law. Thirdly, if you're driving in poor visibility conditions, you want your rear lights on so that you can be seen.
posted by wierdo at 4:07 PM on September 3, 2012


Just FYI, "Fog lights" are actually "this person is a douchebag" lights unless it's actually foggy.

If your rental car is like my wife's Subaru, just turn your headlights on all the time, her car switches all lights off automatically when the car is off, so no worry about the battery. I suspect many modern cars are like this, but I don't drive one so am not sure.
posted by maxwelton at 5:41 PM on September 3, 2012


Just FYI, "Fog lights" are actually "this person is a douchebag" lights unless it's actually foggy.

But very useful when it actually is. In extremely dense fog, you turn your headlamps off and use only your fog lamps. FWIW I have only encountered those kinds of conditions in one place (rural Rhode Island) but it was routine along one very long, very lonely, very creepy stretch of road.
posted by DarlingBri at 6:25 PM on September 3, 2012


Many cars, like Hondas and Toyotas will not turn the headlights off automatically when you turn off the car.

Also, check the glovebox in the car the the manual and give it a quick check before you drive. The auto manufacturers seem to go out of their way to do things differently from each other, and headlight and wiper controls are a special pet peeve of mine.
posted by reddot at 4:48 AM on September 4, 2012


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