Truck question

[PierreR89]

This might be a stupid question but anyways.
I have always wondered what the searchlights on some US trucks are for.
Do the driver use them to find the correct trailernumber they are going to pick up when it is dark outside and there are no other lights around exept theirs?
So they dont have to go out of the cab and walk around on foot to find it?
Or they use them for something completley different?

I have only seen them on US trucks on euro trucks they dont exist and the only extra lights they have are aux lights that turns on with the highbeams.
Some might have searchlights but then they are used for the job they use the truck for.

While i am asking stupid questions what does the SAR stand for on some kenwoth trucks?
Never been able to find that out.

[plastic trucker]

A lot of times they're used to check out the rear of trailer during the night without having to stop.

[The Junkman]

I've rarely seen spot lamps on commercial tractor (the truck part)/trailer combinations.  I'm talking of cab mounted spot lamps controlled and aimed by the driver.  Now, on the other hand, commercial trucks have to make deliveries in all kinds of weather (it has to go through!) and many have foglamps or auxiliary driving lights mainly mounted to the front end/bumper.  Another consideration is that, while a first world country, many trucks have to traverse narrow secondary roads and some have lights mounted so that the driver can see where the edge of the roadway is located. Legally, at least in California, only two sets (a total of 4) of forward facing lights are allowed to be on at the same time.  High beam lights are considered to meet that 4 lamp limit.  So the truck can have one set of low beams lamps and one set of auxiliary lamps in use.  Plus there are often lamps mounted to the rear of the cab to keep track of what's happening to the trailer but they have to be carefully aimed so that they don't blind drivers overtaking from the rear.

I'd never heard the term SAR before so I had to look it up.  "The term SAR was derived from the American Kenworth item listing: Short [Bonnet], Australian, Right hand drive."  We don't come upon Kenworth SAR's in the wilds of California.  https://www.pressreader.com/australia/big-rigs/20160812/281728383905672

Edited May 9, 2020 by The Junkman

[highway]

Pierre, the answer to your question depends on where on the truck the spotlights are installed. If you are asking about cab mounted ones like these on the red Kenworth..

...those are not very common on trucks in the US and mostly on independently owned rigs the rare times when they are seen. I would guess, since I have never driven a rig with them on but wish I had them a few times in dark areas to find addresses for shippers or receivers late at night. 

A much more common place for spotlights or auxiliary lights to be mounted are on the sleeper or the sleeper fairings facing rearwards like on the blue Prostar in this picture. 

Those are NOT as previous said to check on the trailer at night without stopping, those are used for extra lighting in addition to the factory "hook up" lights in the back of the cab for hooking up to trailers at night. They are also sometimes wired into the reverse lights to come on with the standard reverse lights to give additional lighting to the area a driver is trying to back into.  

[PierreR89]

Thanks, yes i was asking about those mounted on the side of the cab roof.
 

[DRIPTROIT 71]

I’m not sure why they were added to trucks. I used to commonly see them back in the 80s. My dad always used his to locate his trailer number at night. That was the only time that I remember seeing his used, except possibly checking for an address. Outside lighting was not as good back then as it is now.