Cop Car Zig-Zag Maneuver

Sometimes cops do this thing on California highways where they zig-zag across all lanes and force the traffic to slow to a crawl or a stop. Then, a few minutes later, they speed off. There's no obvious reason that I can see for doing this. Why do they do it?

cops are dicks

http://answers.yahoo.com/question/index?qid=20070725194914AA36s97

j/k don't they usually do this to herd traffic around accidents and lane closures and whatnot?

There wasn't an apparent hazardous situation today on 280 when they did it, just FYI.

Nor lane closures or anything out of the ordinary. (xp)

I doubt that it's a means of reducing general traffic speed for more than a few moments, since it's not really a very clear message that you shouldn't be driving 80-90 on 280.

hey tell that to yahoo answers buddy

I already did; I yelled that at my computer monitor.

have u tried contacting ur local police station

My wild guess would be that it's a way of managing traffic flow in general -- they've got enough science and observation going around this stuff to figure out where (e.g.) creating a speed reduction might help reduce a bottleneck up ahead, or whatever else

There wasn't an apparent hazardous situation today on 280 when they did it, just FYI.

well maybe the hazardous situation was cleared up by the time you drove by

it is probably a way of saying slow the fuck down without doing any of that tedious "interacting with civilians and filing subsequent paperwork" bullshit

They usually do it to clear cars out of the median. In many states, California included, people with flat tires or in accidents pull over to the center median, but a cop isn't allowed to leave you there - you should be on the shoulder of the road if it's safe to go there. If the car is in a condition where it can slowly move across the highway, a cop will usually instruct the person to drive across once they see traffic clear out. The cop will then go an exit or two back up the highway and do the zig-zaggy thing to give the pulled-over car some time to get to the shoulder. If you see the cop just takes off at normal speed after this, the car with the flat/incident likely was pulled over already when you drove by.

They also do this when repair people/crews/construction/emergency vehicles need to set up in some lanes and they need the road to be free of traffic for a few minutes.