If you have the permit, you have all already had this little pressure, this little tension:Didn't I just get flashed? You were driving a little fast, and you think you were caught by the patrol, but it may just be an impression.
Besides, you never really know which meter to trust… the car or the GPS? Well, it's neither. I'll explain.
86% of French people use a GPS when they are in their car, that is to say that almost 9 out of 10 French people have two different meters. And there, there are 2 teams:those who watch the speedometer of the car and those who watch Waze!
Let's start with the purists with the car counter called tachograph . Well know that your car never gives you the right speed, and that's on purpose. It displays a higher speed than it actually is. Depending on the model, the real speed is boosted by 1 to 10%.
Example:If your speedometer shows a speed of 100 km/h, it could actually be that you are going between 91 and 99 km/h.
Why ? It's just a security measure.
On the other hand, the tachograph of the car will never display a lower speed than the reality . It is not a fantasy of the manufacturers but indeed the law which requires it:(the ECE R39 regulation to be precise).
So if we recap, if you follow the speedometer of your car, you will always be below reality, so you are not taking any risks. No ticket, no less points.
BUT… I see you coming. There are among you people who like precision, who want exactness. It's time to talk about GPS.
Well, the GPS also has its flaws. The main thing:it works with satellites, so you have to capture… and capture well. Otherwise we end up with a latency time in the display and therefore an erroneous speed.
How it works ? Depending on the number of satellites available, the visibility around the car or the algorithm used, the GPS can be more or less precise.
So here are some tips to get the most accurate GPS speed possible.
As you will have understood, having a precise speed in a car is not quite that yet. You can also rely on roadside speed cameras (in town, or near schools) to try to compare with what is displayed in your car.
But know that speed is always subject to judgment… even for the police. This is the famous expression “measured speed, corrected speed” .
When speed cameras measure speed, they always correct the speed to give themselves a margin of error. It gives 5km/h less if you are below 100km/h, and 5% less if you are above 100 km/h.
Well, the best is still to go quietly, and that will leave you more time to listen to episodes of Dying less stupid and more.
That's it, now you know everything.
