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Speedometer says I wasn't speeding

My speedometer says I wasn’t speeding, but I got a ticket

“But officer, my speedometer says I was only going 50 km/h. I’m sure I wasn’t speeding!”

You plead with the officer, but receive a speeding ticket anyways even though you were sure, absolutely certain, that you were not breaking the law.

So how do you know whether the officer’s reading of your speed was different? Was their reading more accurate? More importantly, how does the court determine who to believe? Was your reading of the speedometer more accurate, or was the officer’s?

How officers determine your speed

First, the onus is on the prosecution to prove that you were in fact speeding. This can depend on how the officer determined you were going too fast. Was the officer using a recently calibrated radar device they were trained to use? If not, was the officer merely “pacing” your vehicle by remaining a certain distance behind you, and checking their own car’s speedometer? Perhaps the officer purely relied on a visual estimation and did not have a record apart from their own observation of your car.

Often in court, officers will provide evidence as to exactly how they determined you were over the speed limit. Radar and laser instruments should be tested for calibration each day and are accepted by the courts as very reliable devices. Speedometers built-in to the officer’s vehicles are also considered reliable. That is, unless the defendant were to cast some doubt as to just how accurate the officer’s equipment was.

In most cases, officers will have a tag or sticker located within their vehicle stating the date that their cruiser’s speedometer was last calibrated. This step of calibration helps provide credibility to the officer’s evidence. So if the officer’s speedometer was calibrated recently, and there’s no conflicting evidence suggesting it wasn’t as accurate as it could be, the court tends to accept the officer’s speedometer reading.

How can I use my speedometer reading to dispute a speeding ticket?

The courts have established that an officer’s speedometer reading is accepted as evidence as long as there is no conflicting evidence challenging it. In most cases, the officer is not required to prove their equipment was accurate. But what you can do is demonstrate to the court that perhaps their equipment was not accurate. That your reading of the speedometer was more accurate. Often, the best way to do this is to have your speedometer calibrated by a qualified professional, followed by a certificate from that professional that verifies the accuracy of your speedometer. Of course, you’ll also have to prove you were monitoring your speedometer at the time of the alleged offence.

In one speeding ticket dispute, a judge laid out plain advice on how to do this:

…basically the simplest way I can put it is if you were going 51 miles an hour in a 50 mile zone, and your speedometer was showing 40 miles an hour and you were taking somebody dying to the hospital, you’d be guilty of speeding. So the only defence to a speeding charge is if you weren’t speeding and if you’re going by way of your speedometer, that you have some way of knowing your speedometer was right.”

Great advice. But how do I know my speedometer was right?

One thing I might say is that if you run into the situation again where you don’t feel you were speeding, what you should do is calibrate your speedometer, bring in the certificate with you and testify that you looked at your speedometer and that’s what it said.”

It’s far from a guaranteed defence, but if you’re able to prove your speedometer was accurate, then your evidence may put into question the accuracy of the officer’s speedometer. In some cases, it can be more than a year since an officer last had their speedometer calibrated. To the court, it won’t be clear just how accurate the officer’s equipment was, especially if you can prove that you may have more accurate readings.

What about GPS devices? Don’t those also measure speed?

The courts have also accepted evidence from Global Positioning Systems in speeding disputes. The principles are the same, in that if you’re relying on a GPS reading as your defence, you will have to demonstrate that your GPS system is accurately displaying your location and speed at the time of the alleged offence.

It’s happened before. In one dispute, a speed camera caught and photographed a truck as it passed an area where road workers were near. The alleged traffic violation was that the truck driver was traveling too fast in an area where road workers were present. The defendant, however, introduced GPS evidence that showed the truck was actually “fully stopped” at the location where the road workers were. Even though the speed camera’s reading of the truck’s speed was correct, it was the wrong location – thanks to the GPS.

An officer’s equipment is going to be better calibrated in many cases compared to the average road user. That, along with an officer’s experience in determining speed, makes a defence relying on your own vehicle’s speedometer difficult. But in cases where you’re absolutely certain you knew how fast you were going, it might be something to work with.

If you’ve got a speeding ticket, give us a call and we can discuss your options. It never hurts to dispute a traffic ticket.