Considering how close the vehicles are to the bridge height, I wonder how many were inaccurately measured. Like the truck for an example. The driver might have been told that the cargo space was 12ft tall, and so it should have fit just fine. However, in reality the height of the truck is actually 13ft, so a few inches gets taken off the top.
Oh, I didn’t realize that was specifically telling the drivers in the video that they were too tall. I thought it was just a general warning to anyone passing through.
No, it actually measures vehicles if they’re short enough to pass. My guess would be a IR receiver-transmitter combo with a simple “flash if tripped” circuit, but still, that is enough to draw the driver’s attention.
Originally, there was a pair of flashing lights next to a sign that said “Overheight when flashing” that would light up if the sensor was tripped. Then they replaced it with traffic lights that would stop traffic and flash “OVERHEIGHT MUST TURN” like you see here if the sensor was tripped.
Of course, that caused the dumb truck drivers to just floor it and run the red light.
Kinda unrelated runt: I hate when vids like this are served as gifs. You don’t have a media control bar so see your progress and can’t move your position. I’d need to watch the whole thing until I realize oh it loop (gl notice that). Bah.