Have you ever seen a heavy-duty pickup truck and wondered why it has little orange marker lights on the roof? Well, they aren’t there just for show. The United States Department of Transportation mandates these identification lights on vehicles that reach a specific size. Their placement is to protect you. Or alert you. Or something.
Here’s an overview.
What Are the Lights On Top of a Truck Called?
If you take more than a casual glance at larger vehicles, you’ll notice a trio of small amber lights mounted to the roof. You can see the warm orangish, yellowish glow on box trucks, buses, semitrailer trucks, and even some vans and heavy-duty pickup trucks. The three lights up front are coupled with red lights in the back of the vehicle. Those small rear lights are roughly the same size as the amber lights on the leading edge. The rear position varies, depending on the vehicle type.
When you initially consider the identification lights, they don’t make much sense. They effectively provide no illumination, so they don’t help drivers see. Plus, they’re mounted too high on trucks to do any real, productive work. And yet, they’re there for a reason: The DOT says the identification lights are a safety feature. I have no real idea why.
Still, if you make a vehicle more than 80 inches wide, it might fall into one of the various “commercial vehicle” categories. Commercial vehicles this size must have — in the words of the DOT — “three amber front and three red rear identification lamps spaced between 6 and 12 inches apart at the center of the front and rear of the vehicle, as high as practicable.”
This is why you may see these cab roof lights on a Ford F-150 Raptor or Ford F-Series Super Duty trucks (over 80 inches wide) and not on light-duty vehicles or a regular Ford F-150 (79.9 inches wide). Measuring one-tenth of an inch shy of the DOT’s 80-inch threshold is likely not coincidental.
It’s a Rule
So, why do certain vehicles have little amber marker lights on the roof? For some, it’s a rule. And now, when you see them in oncoming traffic, you’ll know the DOT has required cab roof lights on larger trucks since 1989. Wait, noticing the rooftop lights in oncoming traffic probably is why they’re atop heavy-duty commercial trucks. The lights signal drivers that the approaching vehicle takes up more lane space and reminds them to pay attention on the road. And if you think about it, that’s the reason for so many lighting devices and reflectors on commercial vehicles. For others, it just looks good,.
Autotrader can help you find a truck for sale that might or might not need amber roof lights.
This article has been updated since it was originally published. Doug DeMuro contributed to this report. He is an automotive journalist who has written for many online and magazine publications. He once owned a Nissan Cube and a Ferrari 360 Modena. At the same time.
How are the comments dated 2018 before the article was written in 2022? I’m really starting it’s a question autotrader.com credibility. That doesn’t even make sense that there are comments from four years before the article is even written.
Thanks for reading, Guy. There’s an editor’s note at the end of the article indicating the article was updated after its original publication date. That’s why you notice comments with dates earlier than the publication date at the top of the page. Articles throughout the site may be updated to reflect price changes, add new products or techniques, remove outdated material or include other helpful information.
I don’t know what country or what planet y’all are living on but on every heavy duty truck I’ve seen with roof light clearance markers. There are five lights one on each side of the cab and a cluster of three in the middle 1+3+1 = 5.
Look at the F350 at the top of the page and count how many roof light markers that has. If my eyeballs are correct, I see 5.
I expect a higher level quality article that has been resurfaced from auto trader than this. “I don’t know” there’s a cop out of I didn’t feel like doing any research for this article I’m writing so let me just wing it. That’s bad journalism. Do better. If you’re gonna be a journalist and writing articles, have some information and know what you’re talking about. It’s sad to have to come to read the comments to find out more than the author knows about the subject.
Thanks for reading, Guy. The DOT rule, 49 CFR 393.11, applies to commercial vehicles the agency regulates. Three center lights are an indication of height. One light on each corner are for width. Wide non-commercial vehicles or commercial vehicles without DOT regulation may have the lights just in case or in the grille because they look cool.
I don’t know what country or planet y’all are living on but I’ve always seen five lights across the top of heavy duty trucks; a cluster of three towards the center and one on each outer side. 1+3+1 =5
Thanks for reading, Guy. The DOT rule, 49 CFR 393.11, applies to commercial vehicles the agency regulates. Three center lights are an indication of height. One light on each corner are for width. Wide non-commercial vehicles or commercial vehicles without DOT regulation may have the lights just in case or in the grille because they look cool.
Those three high mounted amber lights on the F-150 Raptor are actually in the top of the grille, not on the roof.
“The government mandates them as a safety feature. I have no real idea why.”
This is journalism?
I came here for the same response. How can you write this article and not come to the conclusion that at night when a truck is coming, you do not know it’s a big wide truck unless you see those orange lights outlining it’s shape? You cannot tell the vehicle by the blinding headlights coming at you. If you are about to make a sudden stop at a red light and you look in your rearview and see those amber lights, coast through the light because the truck behind you might be too big and heavy to also make that sudden stop and your car will be pushed into the intersection — and this has happened to a close friend who had a truck push her into and under the 18 wheeler in front of her. These lights prevent you from being pulled from your car by the jaws of life and medevaced to a trauma center.
No, it’s Doug DeMuro and he isn’t a journalist
Early on in trucking, before there were radios or Clair Broadcast, these 3 lights were also used to signal other trucks. Police ahead, accident, I need help, etc. I have never been able to find out the exact signal combinations. Since they were traditionally on the trucks for this purpose, the govt Mandate keeping them.
Early on in trucking, before there were radios or Clair Broadcast, these 3 lights were also used to signal other trucks. Police ahead, accident, I need help, etc. I have never been able to find out the exact signal combinations. Since they were traditionally on the trucks for this purpose, the govt Mandate keeping them.
They identify a rig that is extra wide when you’re coming at them head on at night, so you can note that they may be taking extra room. C’mon Doug, it’s not that hard to figure out.
come on Mr. Demuro really? , I’m a retired truck driver and those lights, even when I think about them, DO make sense, they’ve saved lives because “other” drivers are able to see them.
Next time do research on your subject or start your column off by stating ..this is your personal opinion
So what would you have the “other ” drivers do (or think) when they see those little orange lights?
These lights are extremely helpful in blizzard and white out conditions. They make the trucks more visible as the orange lights cut through the snow and fog better than white lights or tail lights.
personally i think they look “cool” and want to add them to my ford ranger level II!!
If you see cab lights coming your way and let’s say you’re on a thin road and you’re in a wide truck (or hauling a wide trailer) …guess what. Cab lights may have just saved you from crashing, because one ( or both) of you made provisions to get over. Now, concerning 3/4 and 1 ton trucks that are not 80 inches wide, these marker lights are completely optional. Its good thing too, I would install them if I am consistently hauling loads at night with a wide trailer, for example… farmers…totally a visual safety regulation. NOT to see if your rig is close to a tunnels low clearance. A trucker knows the height of his truck. And all low clearance structures are identified with signs and such.
when I read this, as I soon as I saw that dough wrote it, I immediately started reading it in my head in his voice, with all the major pitch changes included
Doug you silly bastard, stick to telling people why their $50,000.00 car is worth $500,000.00 to some idiot on You tube.
This barely even scratched the surface as to the practical and very useful reason those lights exist on large trucks. they are actually on tops of the larger and commercial trucks to help people see when they go into low tunnels or under bridges if they are going to clear passing underneath those obstacles or not fit he lights clear with no problem, hammer down and keep on going.
if you pop one off it’s a whole lot cheaper and easier to replace one of those little lights as it is to replace the whole roof of a semi or large truck roof. that’s the main reason they are there though some idiots don’t even pay attention to those or the street signs telling you how low a bridge is and to this day continue to rip the tops and sides off of large box trucks and semi trucks all over the country still. Just proves that not everyone was cut out for driving large trucks or just driving in general.
I agree with most of this however if youre questioning whether or not youre going to fit, shearing off the light ts only work when youre marginally close to the roof. Any lower and youre hitting the roof anyway if you’re using the lights as a test tool. besides if you hit those lights youre more likely going to do some roof damage at the same time
Okay so now I’m really confused. I’ve been looking at some Ford F240 Super Duty trucks. Some have the roof lights, some don’t. Explain that.
Always seemed obvious to me. As the truck approaches the crest of a hill during darkness it is detected sooner by oncoming traffic.
I have 2 Ford F-250 superdutys 2000 and a 2002 both 4×4 one has Cab lights and the other does not why is that same trucks?
When you drive at night down the highway you often see the amber lights coming over the tops of hills sooner than the headlights. So that would be an indicator to turn off your high beams to prevent from blinding the driver.
Had a 1978 half ton Chevy short bed with factory clearance lights on cab.
These are only required on heavy duty pickup trucks with dual rear wheels. The ones with single rear wheels are usually 79.9 inches wide, but the clearance lights are offered as an option on SRW trucks. The one in the picture appears to be a SRW truck.
Actually they are mandated for commercial trucks like 2500s F250s and up doesnt matter if they are dually or not its still mandated
It’s one of those things that has been mandated on commercial trucks since the 1930’s (like ‘glad-hand’ air brake connectors). The rest of the world has moved on….
The rest of the world still uses marker lights , so I don’t see how they have “moved on”
Yes… they are for clearance – width and height of the vehicle… however on some trucks like the Ram and Raptor, they are used for width only as they are not always mounted up high on the roof, but in some cases integrated within the front grill or rear bumper.
Amber lights means the vehicle is heading towards you. Red lights means that the vehicle is heading the same direction as you are. This is super important because a vehicle can be in your lane and if you see amber lights then you know it may be trying to pass another vehicle and a potential danger is present. If red lights are ahead, then you automatically know that a wider vehicle is ahead and it may be traveling slower than you so beware.
So, it’s all about safety as far as I can tell.”
These lights are called clearance lights. They are there to show the clearance of the vehicle. So, that you can see it is an 18-wheeler Vs a school bus, and so on.
They’re dual purpose (in a way). As indicated 3 lights in centre indicate the presence of a wide vehicle, so why do most HD trucks have 5 since they could easily run with 3 and save the cost on 2 lights which is an automaker move. The outside two lights are actually required to be there to mark the vehicles overall width.
Doug, let me clear things up. If I am on the freeway at night and see these roof lights closing in on my rear view mirror, I will get out of the way. They look like the lights on a large commercial vehicle. Or I will speed up and increase my distance from this vehicle. There is a good chance that this vehicle will not stop as quickly as mine should I experience a potential collision in front of me. This is an accident avoidance measure which makes perfect sense.
I installed them on my astro van for this exact reason, despite the fact the vehicle is not large enough to need them (unless I was towing my camping trailer)
Fun fact: In some states you can get ticketed if one is out despite it being an optional lighting accessory that isn’t mandatory for non-commercial use. So if you have them, make sure they all work.
“if it’s there it has to work” is the phrase
“three amber front and three red rear identification lamps spaced between 6 and 12 inches apart at the center”
WIth the center three and the tailights its five also.