On I-235 southbound there is a sign that says "ODOT Test Sign" on one of the sign structures near the NE 23rd St. exit. It's up there with a couple of other larger signs, but I have always been puzzled as to what its purpose is; it doesn't have any sort of useful information on it...all it says is that it is a "test sign"!

What exactly is the purpose of this sign? What kind of tests would ODOT need to perform on a sign...maybe materials on the sign or something? Or maybe it's just some sort of silly inside joke? Someone enlighten me here!

There are a few around the city, I believe they may have hidden cameras in/behind them. Seems like I saw a "peephole" on the one I saw.

I saw the sign. It was pretty dang small. I wonder if ODOT is testing the font size or something? I don't know how they would get feedback though. . .

I saw the sign. It was pretty dang small. I wonder if ODOT is testing the font size or something? I don't know how they would get feedback though. . .

There's a high def cam in there which has a telephoto lens in it that zooms in on driver's responses as they pass by. It sees them squinting to read the sign indicating that the font is too small. J/K, I don't really know...lol.

On I-235 southbound there is a sign that says "ODOT Test Sign" on one of the sign structures near the NE 23rd St. exit. It's up there with a couple of other larger signs, but I have always been puzzled as to what its purpose is; it doesn't have any sort of useful information on it...all it says is that it is a "test sign"!

What exactly is the purpose of this sign? What kind of tests would ODOT need to perform on a sign...maybe materials on the sign or something? Or maybe it's just some sort of silly inside joke? Someone enlighten me here!

They're probably testing the decals applied to the sheetmetal (I don't think they really 'paint' highway signs anymore) for resistance to fading.

They're probably testing the decals applied to the sheetmetal (I don't think they really 'paint' highway signs anymore) for resistance to fading.
That's the reason, the same thing with striping test sections on the road to test various paints and tapes for wear resistance.

I thought that they still screen printed signs.