This is a question that has been in my mind for years. I wonder if others have noticed it.
I regularly drive, with and without our RV 5th Wheel RV, in locations where special speed signs, perhaps radar reading, post the speed that each vehicle is moving at the site. Such signs at school crossings, construction sites, etc., are common. These signs usually follow warning signs that speed is restricted ahead.
In our area all of the local speed signs, such as school area or school crossing signs, or other such signs, register almost exactly the speed that I am moving when they show the speed and changing speed. So I know that my speedometer(s) must be accurate.
However, I have noticed that on the Interstate Highways, the speed signs at construction sites almost always read about 5 MPH faster than my speedometer reading in my vehicle as I approach and pass the sign.
Has anyone else noticed this too? I often think it the sign is set on purpose so that traffic will slow down even slower than the posted speed limit at those sites.
