Anonymous asked in Politics & GovernmentLaw Enforcement & Police · 8 years ago

Why do police sometimes do a zig zag motion on the freeway to compleatly halt traffic?

Why do police sometimes do a zig zag motion on the freeway to compleatly halt traffic?

Its usually when there is no traffic at all then you see this cop doing this, first time I saw this I thought someone stole the cop car or he was drunk

9 Answers

  • Anonymous
    8 years ago
    Best Answer

    Copied directly from


    Everyday on California freeways there are objects which wind up in the lanes of traffic. These obstacles can include such things as christmas trees, mattresses, construction equipment, lawn trimmings, clothes, garbage, furniture and vehicles which have become disabled, wound up facing the wrong way on the shoulders, or involved in collisions. Removing this blockage from the roads is part of the normal routine of the California Highway Patrol.

    There are several ways this can be accomplished. First, an Officer can wait for a natural break in the flow of traffic. They can them retrieve the object, or push it out of the lanes. The large vertical bumpers you see on the front of CHP cars are used to push vehicles without damaging either vehicle. On most freeways in major metropolitan areas, a sufficiently long "natural break" is very rare. In these cases, Officers will create their own "traffic break." With one Officer standing by at the scene of the obstacle, another Officer will get on the freeway at a point before the scene of the problem. The Officer in the car, or the motorcycle, will turn on their emergency lights. Sometimes, they will even activate the vehicle s siren. They will then start moving in the direction of the obstruction. The Officer will start to zig-zag back and forth across all lanes of traffic until they have the attention of all of the vehicles behind them. This zig-zagging motion is intended to keep all vehicles behind the CHP vehicle. When the Officer is convinced that all of the vehicles have seen the patrol car, they will slow down. This slowing down will create a gap between the vehicles traveling behind the CHP vehicle, and those traveling at normal speeds in front of the patrol car. Normally, the Officer creating the break will then use the radio to give the Officer at the scene of the problem a description of the last car traveling at regular speeds. When the last car goes by, the Officer at the scene will then either run out into the lanes to remove the item, they will push the disabled vehicle out of the way, or they will instruct the driver of a vehicle facing the wrong way that it is safe to make a u-turn, and get on their way.

    So, the next time you see a CHP vehicle driving back and forth across all of the lanes with its lights flashing, you do not have to worry about the Officer having had too much to drink. You will know that they are running a "traffic break."


    Quite often, at the scene of a major accident or when something happens which blocks most of the lanes of the freeway, traffic will rapidly back up. Traffic coming to a rapid halt can create dangerous situations due to inattentive drivers. There have been many secondary crashes in the backup caused by the original problem. Unfortunately, these secondary crashes are sometimes worse than the original event.

    When a California Highway Patrol Officer arrives at the scene, they will notice the situation that is causing the problem. Then, based on their assessment of how long it will take for the roadway to be cleared, and how much traffic has backed up, they may request a Sig Alert to be issued or help from other CHP Officers. One of the ways an Officer can reduce the odds of a crash occurring in the traffic backup, is to slow the approaching traffic. This can be accomplished by a traffic break. Sometimes, however, a single traffic break may not last long enough for a complicated situation. In this case, the Officer at the scene may request other Officers perform what are called "round robins." Round robins" are a continuing series of traffic breaks designed to slow down traffic. Other Officers may go as far away as several miles to start a traffic break. They will slow the traffic down; and, keep it slow until they pass the scene of the problem. The Officer will then go back, and do it again.

    So, the next time you hear a traffic report on your radio talking about the CHP doing round robins, you will know it is not a sports tournament; but, it is an effort to keep the freeway as safe as possible.

  • 3 years ago


    Source(s): Criminal Record Search Database :
  • 8 years ago

    I believe when police sometimes do a zig zag motion on the freeway to completely halt traffic they do this in order to completely halt traffic. In the event the police do not have to completely halt traffic they will sometimes do a zig zag motion on the freeway and completely halt traffic but then let some of the traffic pass after they have compleatly halted traffic so as to not completely halt traffic. But for the most part when police sometimes do a zig zag motion on the freeway to completely halt traffic they are doing it so as to completely halt traffic.

  • 8 years ago

    It's called a round-robin, to slow and eventually stop all traffic on the freeway to clear a hazard, like a ladder or furniture or other such object of the road..

    Since I drove a lot for my business, I'm usually in one about once a tear or so.

    Too bad the cop above didn't quite answer this question all that responsibly.

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  • 8 years ago

    Because of some problem ahead on the freeway.

  • Josh
    Lv 7
    8 years ago

    Perhaps it's because of knuckleheads that fail to pull over to the side when they are in pursuit

  • Steve
    Lv 5
    8 years ago

    Maybe because of road construction or an accident

  • 8 years ago

    The cop was probably drunk.

    He probably just left the FOP lodge.

    Source(s): ....I am a retired police officer. I retired as a sergeant, after 29 years, from a very large department, about 12,000 officers. I was a patrol officer for 4 years in a very diverse area. I was a tactical officer in the high rise project areas of my city. We called it vertical patrol in that we walked the the stairways of the high rises most of the time. I did that for 5 years and was promoted by test to detective. I worked violent crime (homicide, sex, officer involved shootings, robbery, kidnapping, serious non property incidents) for 11 years until I was promoted to sergeant. I worked as a street supervisor, a bicycle patrol supervisor and a desk sergeant/watch commander. During my time as a tactical officer and a detective I was a unit representative for the police union. I have a B.A in English and an M.S. in Law Enforcement Administration....
  • Anonymous
    8 years ago

    because they're sick like that :L:L

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