This is a traffic question, but one I have wondered about for some time now for reasons I will shortly get into. We all know what it means when a vehicle has a flashing red (signifying emergency) or flashing blue (signifying police) light on its vehicle. It means let it pass and let it thru the intersection (even if the light is green for you). But what does the flashing yellow mean exactly? Yes, I know it means hazard and slow/fast moving vehicle and all that. But what does it allow the vehicle to do, and what specifically are other motorists supposed to do when they see this?
The reason why I ask is, a while back, when ambulances for animals became more common where I live, I noticed they only could have a flashing yellow light on top of their vehicle. And I have wondered for the longest time what this specifically entitled them to do. Obviously it was not the intention of lawmakers to let them have right of way thru red-lights and the like, naturally. But what advantages, if any, did a flashing yellow give them? Whatever the advantage, it would seem tow trucks and snow plows have the same priviledges.
Construction vehicles and hearses usually have flashing yellow lights, too.
I don’t think that flashing yellow lights have any purpose other than to make people notice you. I’ve heard that anyone can put them their vehicle (at least in my state). My boss has one on top of his pickup truck. It’s lame as hell, but who’s gonna say anything to him?
Only bona fide emergency vehicles can have red or blue lights (the details may vary by jurisdiction). I think just about any vehicle can have a flashing yellow light to indicate caution (tow trucks, delivery vans, whatever). Having a yellow light gives confers no special status or priveleges, though some vehicles may have special advantages by virtue of their mission rather than the light. For example, a tow truck can service a car on the shoulder when considered an emergency. But private security cars sport yellow lights, although AFAIK they don’t have any special rights.
Once I called the police because I saw a tow truck blatantly running a red light to get to an accident. They confirmed that he had no legal right to do so but probably wouldn’t do anything unless a police officer had seen it.
In Illinois, at least, the yellow light doesn’t entitle the snowplow, tow truck, or whatever, to any special treatment from other motorists, other than, “yo, watch out for the frickin’ snowplow”. Cite: Driver’s Ed class, 1972.
And I’ve never seen tow trucks or snowplows or other Decatur city vehicles with yellow lights go through red lights. They have to sit there and wait just like the rest of us, nyah.
But funeral processions do go through red lights, but that’s a function of them being “funeral processions”, not anything to do with rights entailed by having a yellow light on top of the car in front.
A while back, I had a truck with a snowplow, and I asked a policeman friend about the need for a yellow flashing light. He told me that I should install one and use it only when plowing - it signified that I was an encumbered vehicle that others should avoid. He specifically noted that the flashing light did not give me any special privileges, and that it was not to be used in normal vehicle operations. (Though he seemed to know his stuff, note that this was only one cop in one location.)
This advice contrasts with how yellow lights are often used. Some drivers seem to think that having one makes them a sort of “junior cop”, entitled to deference from other motorists. Perhaps this is true in some locations, though I’m skeptical.
In Cheektowaga, blue lights apparently mean “the donuts are getting cold.”
In blue-collar suburbs of Buffalo, where it seems like every other person is a volunteer fireman, you’ll see blue lights mounted on everything from minivans to old Geos. I’ve seen quite a bit of abuse, too … a flashing blue light, a Buick Century running past a red light, and turning into the parking lot of a donut shop or Greek diner.
Up here it freaks people out from other states. The cop cars (Sheriff, State Trooper, etc) have all red lights. Most other states’ police have some amount of blue, or all blue, with all red reserved for emergency (fire) vehicles. My friends from Virginia are always asking me “why is that Fire Chief pulling someone over?”
Snowclearing equipment around here has orange and/or blue strobes. Most of the ones I see with blue only are the little tractors that clean the sidewalks. (bobcat?)
Only police vehicles get red and blue, fire and ambulance get red only.
I always took the orange to mean something along the lines of: “this vehicle is to be noticed because it won’t act like most other vehicles – it goes slower (construction equipment), the driver can’t see you very well (snowplow), it stops frequently (garbage truck), or there might be people on the roadway nearby (utility or tow truck)”.
A few years ago, I knew someone who was a volunteer firefighter. He explained to me the standard strobe colors:
Red - I am an emergency vehicle. PULL OVER!
Blue - I am on urgent business. Please let me through.
Yellow - I am doing something funky. Please be careful around me.
Green - I am the command post. Warning: Boss inside.
There may be other strobe colors that I’ve forgotten.
In UK flashing green means emergency doctor on way to incident. But you hardly ever see them. Apparently it just means please get out the way, but you are not obliged to,
Red Only: Fire/ambulance
Red & blue: Police
Yellow: Pay attention to me
Firefighters have a green light on their personal vehicles. This light is usually mounted on the front bumper, or behind the grille, rather than on top of the vehicle. It is only used when the firefighter is on his/her way to the fire station in response to an emergency call-in.
CalTrans is required to use as many people as possible for mundane tasks. For sweeping the freeway, they get one or two CHP cruisers on point guard, then two or three sweepers to stir the greasy dirt and leaves around thoroughly, then a flare truck to mark off the lane being cleaned, and the next one over to create a demilitarized zone, then a sign truck with a big flashing arrow, then another CHP cruiser for the rear guard. The kingly procession marches slowly down the freeway to ensure that no stone goes unturned, then returned, then unreturned.
