Speed Camera Accuracy (or lack thereof)

 

Speed Cameras in Canada

On a similar vain, the CBC reported that there are concerns about the validity of speed cameras. Apparently the cameras are not being tested in a consistent manner by various police agencies across the country.

I would think that, like blood-alcohol units used to test for impaired driving, speed cameras would have to be calibrated on a frequent basis... but it seems the manufacturer of the most common equipment used in Canada does not feel it necessary. That seems a bit strange!

http://www.cbc.ca/news/canada/inconsistent-radar-testing-1.3...

I Think

Mobile radar devices need to be calibrated / certified about every 30 days.

I'm not sure about the ones that are stationary.

--
Never argue with a pig. It makes you look foolish and it anoys the hell out of the pig!

Speed Cameras

There were stories of people getting speeding tickets for going 110 MPH around a curve where a camera was set up in Baltimore.

It would be impossible for anyone to go that fast around the curve.

Plenty of other stories as well.

Baltimore is in the process of getting their cameras back up and running.

Moving Wall...

pratzert wrote:

There were stories of people getting speeding tickets for going 110 MPH around a curve where a camera was set up in Baltimore.

Some years ago a driver received a speeding ticket via a radar gun. He took the ticket into court and had the cop shoot one of the walls. It seems like the radar gun showed the wall was traveling at something like 17 mph. Needless to say the judge dismissed the ticket.

Nuvi1300WTGPS

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I'm not really lost.... just temporarily misplaced!

interesting article

They should move to laser based system. If these systems are going to be used they must be perfect every time.

radar

pratzert wrote:

There were stories of people getting speeding tickets for going 110 MPH around a curve where a camera was set up in Baltimore.

It would be impossible for anyone to go that fast around the curve.

Plenty of other stories as well.

Baltimore is in the process of getting their cameras back up and running.

radar cannot measure speed accurately going through a curve, when I took physics a long time ago my physics professor had all the calculations on why. the bad thing is the judge would not care.

It's often hard to argue

It's often hard to argue with people who do not want to have an open mind.

745kmh

several hundred tickets issued on the Calder highway
directly under the runway approach for Tullamarine airport Melbourne, tickets up to 700km over the limit

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If only ..

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blake7mstr wrote:
pratzert wrote:

There were stories of people getting speeding tickets for going 110 MPH around a curve where a camera was set up in Baltimore.

It would be impossible for anyone to go that fast around the curve.

Plenty of other stories as well.

Baltimore is in the process of getting their cameras back up and running.

radar cannot measure speed accurately going through a curve, when I took physics a long time ago my physics professor had all the calculations on why. the bad thing is the judge would not care.

Radar is most accurate when the vehicle is moving at a plane at a 90 degree angle to the source -- neither getting closer nor farther. Like if the radar gun is on the left rail of a ladder, pointed at the right rail, and the vehicle is driving up or down the right rail.

If the vehicle were to veer off the rail and towards the radar gun (such as driving around a curve), the radar will read a higher than actual speed. If it veered away from the source it would read a lower than actual speed.

gosh

With a couple of places not issuing tickets until 12 mph over the limit, we're really getting carried away to believe the technology is at fault when one gets a ticket.

I always remember seeing a newspaper in the supermarket where the headline said a dog stole a woman's car and sped away. I felt that the story was made up, but even if it were not, it'd be a really isolated case.

You're also supposed to calibrate a torque wrench every 12 mos. Honestly? I don't--I'm only working on my own cars. But I borrowed a tool my buddy has, and guess what, the calibration has never changed over 4 years. His device is not NIST, but really sometimes, you just have to accept reality and what's practical.

interesting

blake7mstr wrote:
pratzert wrote:

There were stories of people getting speeding tickets for going 110 MPH around a curve where a camera was set up in Baltimore.

It would be impossible for anyone to go that fast around the curve.

Plenty of other stories as well.

Baltimore is in the process of getting their cameras back up and running.

radar cannot measure speed accurately going through a curve, when I took physics a long time ago my physics professor had all the calculations on why. the bad thing is the judge would not care.

That you mention physics, I was in AP and even took it in college, but eventually went into b school. The lesson I remember is 5252. It seems that honestly very few can relate to the topic, yet it has many practical senses. Most people, it seems, can't even understand how mpg works, let alone instantaneous velocity (I really think one needs to have an understanding of calc to relate). How many times have you heard someone say, yah, I know my car says 87 in the manual, but I get better mileage when I use super.

Digital radar processing

A modern radar with all digital signal processing should never need to be calibrated. There should be no parts that can change over time and affect the answer. This is different from older analog based designs where accounting for parts whose value changed over time was critically important.

Every new unit absolutely should be certified to be accurate. There is potential for the wrong part to be used at manufacturing or for an “unimportant” design change to actually change the result. Although it does seem irresponsible for a local government to not verify proper operation on a regular basis.

For the simple case, a doppler radar should give the correct answer when the vehicle is moving directly toward the radar. Any degree of obliqueness then reduces the apparent speed. At an angle of about 11.5 degrees the apparent speed is reduced about 2%, so the effect of a curve is normally insignificant.

The result of a double reflection can be significant as it doubles the apparent speed. These would seem most likely when buildings are present on the opposite side of the street from the radar and the vehicle is a large truck.

If the law says 12 MPH, then if radar is off its illegal!

johnnatash4 wrote:

With a couple of places not issuing tickets until 12 mph over the limit, we're really getting carried away to believe the technology is at fault when one gets a ticket.

I always remember seeing a newspaper in the supermarket where the headline said a dog stole a woman's car and sped away. I felt that the story was made up, but even if it were not, it'd be a really isolated case.

You're also supposed to calibrate a torque wrench every 12 mos. Honestly? I don't--I'm only working on my own cars. But I borrowed a tool my buddy has, and guess what, the calibration has never changed over 4 years. His device is not NIST, but really sometimes, you just have to accept reality and what's practical.

12 mph is still 12 mph, if calibration is off then 12mph is off by that number. Would you buy gas or groceries if measuring device was off, thats why we have Weights and Measures people that check, why not for RLC's? When Tucson and Pima County had RLC's the Contractor did the Calibration, would you trust them???

there are a lot of problems

windwalker wrote:
johnnatash4 wrote:

With a couple of places not issuing tickets until 12 mph over the limit, we're really getting carried away to believe the technology is at fault when one gets a ticket.

I always remember seeing a newspaper in the supermarket where the headline said a dog stole a woman's car and sped away. I felt that the story was made up, but even if it were not, it'd be a really isolated case.

You're also supposed to calibrate a torque wrench every 12 mos. Honestly? I don't--I'm only working on my own cars. But I borrowed a tool my buddy has, and guess what, the calibration has never changed over 4 years. His device is not NIST, but really sometimes, you just have to accept reality and what's practical.

12 mph is still 12 mph, if calibration is off then 12mph is off by that number. Would you buy gas or groceries if measuring device was off, thats why we have Weights and Measures people that check, why not for RLC's? When Tucson and Pima County had RLC's the Contractor did the Calibration, would you trust them???

in this world. I am willing to bet that people are not getting tickets for doing 37 in a 25, when they were actually going 25, or 26, or 33. Meaning, the people who are always crying about getting tickets

a) actually have never gotten one, but speak in riddles/theories

b) committed the offense and are simply angry

c) like to play devil's advocate

d) are not familiar with 1787

To use real world examples, as a short guy how tall he is, and how much he makes, when he's trying to date women. Suddenly 6' is the new 5'4"

I would buy that if it was a Officer giving the ticket

But as said many times here "the Camera never lies"!! If a LEO stops you for speeding, he has "Officer's Discretion" to decide if you deserve a ticket, that's fair. If a RLC claims you are speeding, "A Camera never lies", so if its calibration is off 1mph, it is lying! If they make a law that only over 12mph, then 36 in a 25 is still not legally citable, "That's the law"!

here's where you're missing the point

windwalker wrote:

But as said many times here "the Camera never lies"!! If a LEO stops you for speeding, he has "Officer's Discretion" to decide if you deserve a ticket, that's fair. If a RLC claims you are speeding, "A Camera never lies", so if its calibration is off 1mph, it is lying! If they make a law that only over 12mph, then 36 in a 25 is still not legally citable, "That's the law"!

When the posted speed limit is 25,

26-30 = $x
31-35 = $x
36-40 = $x

You can ask around, it's pretty uncommon for a police office to decide to summons you for 26 in a 25, even though the law has a specified fine for being 1 over.

They have set the system to only issue the violation at 12 over in MD. NYC is 11.

Is that like going to a cop and saying you got ripped off on an illicit transaction or what? Yeah, I gave the girl $150, but then she....

I was going 36 in a 25 and I am protesting the $40 fine. Now that is just dumb.

If you guys were managing a co. or township etc., I don't think anything could ever get done. 36 in a 25, wow.

Then lets throw out all laws if you say they don't have to be

exact. I stated there is a great difference between a Officer and a RLC, Officer has discretion. A RLC "Never lies" so if the law states 12 miles it should be 12 miles. If you don't want me going past your RLC at 36, change the law, see how long your RLC's will last! Just like many other things that were changed for SC's and RLC's, the 12 mile wiggle room was put there to get "Camels nose under the tent"!

How many times?

windwalker wrote:

But as said many times here "the Camera never lies"!! If a LEO stops you for speeding, he has "Officer's Discretion" to decide if you deserve a ticket, that's fair. If a RLC claims you are speeding, "A Camera never lies", so if its calibration is off 1mph, it is lying! If they make a law that only over 12mph, then 36 in a 25 is still not legally citable, "That's the law"!

@windwalker, let's start by inspecting your statement
as said many times here "the Camera never lies"!!

As far as "here" is concerned, I can only find two people - you and HawaiianFlyer - both of you being opposed to camera - who have ever written the two words "never lies".

It would seem that you are making that statement so you can use it in your argument.

I think that any reasonable person would assume that any electronic device that relies on external input will sometimes draw wrong conclusions. Further, operating parameters are input by employees and they can be done incorrectly.

nonsense

windwalker wrote:

exact. I stated there is a great difference between a Officer and a RLC, Officer has discretion. A RLC "Never lies" so if the law states 12 miles it should be 12 miles. If you don't want me going past your RLC at 36, change the law, see how long your RLC's will last! Just like many other things that were changed for SC's and RLC's, the 12 mile wiggle room was put there to get "Camels nose under the tent"!

You don't manage people (I hope you don't), and like playing devil's advocate with flawed logic.

36 in a 25, is breaking the law, and worthy of a fine.

The 12 mph is to allow for a reasonable amount of human error, that is, the person who is operating the motor vehicle.

It would be interesting...because you know what they say about the internet.

Sometimes you're following

Sometimes you're following the speed of traffic (faster than speed limit), and you are the last in line and get picked off.

Cold It Be

johnnatash4 wrote:

The 12 mph is to allow for a reasonable amount of human error, that is, the person who is operating the motor vehicle.

The 12 mph leway is for variances in speedometer accuracy.???

NAW.. THAT COULDNT POSSIBLLY BE THE REASON!

I know mine sometimes at 60 presents 65 and somtimes presents 61-62.

Come on GOOGLE CAR!!! I'm rooting fer ya' just think

no more tickets!
No more infractions

Come on GOOGLE Cars, get a wiggle on!

--
Never argue with a pig. It makes you look foolish and it anoys the hell out of the pig!

"Its the LAW!"

You argue my statements "A camera never lies", "Going 36 in a 25 Zone", it don't matter! The point is if you make a law that says "cameras will not cite unless 12 miles over posted" then I expect equipment to be calibrated and certified to be accurate!

Again a Officer is given discretion when ticketing, a camera is a non thinking machine that I expect to be accurate!

Going one step further there should also be random Calibration checks by a third party to verify Contractor is not fudging on calibration.

But we voted ours out so it only matters if we travel thru a revenue grubbing community on occasion.