Cop Running Radar Incorrectly?

[Surgeon]

Okay, I posted here because I thought that more people would see it here and I think it's a relevant topic that deserves some attention. The topic: cops running radar incorrectly just to generate revenue. Moderators, if you feel you need to move it please do so.

Today I had an instant-on scare. However, I was only going about 5 mph over the speed limit and I noticed the cop before he tagged me. As I passed him, he started to pull out of his "hiding" spot but he didn't come after me. I figured I was "lucky" but then I began to think about it on the rest of the way to work. Take a look at the map below:

http://maps.google.com/maps?q=75+Whe...0439&t=k&hl=en

Now, if you look at the satellite image at highest zoom, you'll get a better indication of what the terrain looks like. I picked an address out of nowhere but it doesn't show exactly where the cop was hiding. He was hiding on the other side of Wheeler Lane, directly to the right of the red tab but back in the grass.

Now, I was traveling east on Charles River Road and he was facing me. As I began to round the bend, I saw him in the grass and I slowed down. Immediately after I saw him, he sot me. But, isn't this an improper location to run radar? I mean, isn't there some serious cosine error here. He's got to be at a 30 degree angle to the road, at least! If I were given a ticket from a cop running radar here, I would at least have some defense because I know what cosine error is but what about the poor folk who don't? Those travelling west on Charles River Road would have it the worse because they wouldn't even be able to see him before they were targetted (he's hidden behind houses, trees, and brush).

Should I go to the Watertown police department's traffic division and complain about cops running radar here? Instant-on nonetheless!!! It seems obvious to me that he's hiding there because it's harder to see him and the average joe won't complain about the ticket because they don't know proper radar procedure.

[edweird]

But, isn't this an improper location to run radar? I mean, isn't there some serious cosine error here. He's got to be at a 30 degree angle to the road, at least!

The cosine error would decrease the speed reading, so while it's not as accurate as a dead on shot, it doesn't seem inappropriate.

You'd have to check local and state regualtions ragarding whether the PD vehicle has to be visable for a certain distance or not when using radar. Most places I've lived made no allowance for minimum visability, and only had rules about % grade (downhill) and distance from a speed limit change sign. Some places require the radar operator to have a visual tracking history, but don't spell out how much distance that requires.

Ed

[Surgeon]

You're right, cosine error produces a reading below the actual speed. However, a cop knowing this could write a ticket ABOVE what his radar unit was reading. In other words, he would guess how fast you were really travelling.

[brick]

You're right, cosine error produces a reading below the actual speed. However, a cop knowing this could write a ticket ABOVE what his radar unit was reading. In other words, he would guess how fast you were really travelling.

I don't think that this is a very likely scenario. Is it really likely that an officer would just take a guess at the speed based on an un-measured angle? I certainly understand why you would be concerned if this were the case but I can't really see an officer doing it. Then again I also have a hard time seeing an officer sitting in the car with a protractor and scientific calculator. Maybe Roy knows what the real-world practices are? I've seen slightly oblique speed traps but I always assumed that they took the display reading as-is.

[Radar Roy]

True about the Cosine Angle effect, but this would be in the drivers favor, not the officers. If the officer "guessed" and added what he thought your speed was, then you could get this dismissed.

Could be that he wanted to be here because of a special enforcement zone, too many accidents and/or complaints and wants people to see him..

[SmaartAasSaabr]

But the officer can just say "no I didn't" and you're screwed! :x

What's really strange is I actually know that area, there's a big Saab dealership there... (you see how bad things are in Quebec!!)

[Surgeon]

Just for the sake of clarity, I realized that I made a little error on the first post so I'm editting it here adn have already done so in the original. When I say that the cop was directly behind the red tab, I mean that he was behind it in the easterly direction. In other words, if you look at the red tab, he was on the other side of Wheeler Lane, to the right of the red tab. I automatically thought of it being "behind" the red tab because this morning, I was travelling east on Charles River Road (approaching the red tab).

Sorry. :?