Ever stopped at a red light and noticed something odd about the poles holding up the traffic lights? Look closer next time—many of them appear to hover just above the concrete, anchored by visible bolts. This video below explains it all. It’s not a job left unfinished. It is actually clever design, and all about functionality and easy maintenance. Let’s break down why engineers prefer this so-called ‘floating’ base plate setup.
At first, you might think mounting poles directly into concrete would be more stable—after all, that’s how heavy columns are often installed. But traffic light poles are lightweight, hollow, and face constant wind pressure. Instead of brute stability, they need flexibility and precise alignment. Enter the standoff base plate. By resting on leveling nuts, these poles can be fine-tuned for perfect verticality, even when the ground shifts slightly over time. That’s critical for keeping your 30-foot pole from leaning like the Tower of Pisa.
The open design also simplifies maintenance. If the pole tilts after years of wear, it takes just a few nut adjustments to fix it—no heavy cranes required. Plus, the gap helps prevent moisture buildup, reducing corrosion. So next time you’re waiting at an intersection, you’ll know it’s not just clever engineering—it’s practical street smarts. If you’re an infrastructure nut, this slightly older article might spark your interest.
They do the same with free-standing towers and pylons for wind turbines.
Oh, so it has nothing to do with being less of a hazard in motor vehicle accidents? I imagined these “floating” pole mounts were designed to shear off when struck. Hmm… Maybe that’s a different, clever design.
Only small poles are designed to shear. At some point the structure becomes large enough that it is more dangerous for it to topple over the road than for one car to crash into it.
A family member had a solar plant installed at their house recently, I went to watch the installation.
They drilled into the slab, put in some kind of epoxy in the holes (I have no idea what it was, all text was in chinese), put stud fasteners in and then bolted the solar prefab structure base a few inches above ground, and finally encased the legs in cement.
I still have no idea if they did a good job or not. It seem really solid so I sure think so
I’ve got a pack of resin anchor bolts for the brackets to mount an antenna pole to the side of my (brick built) house, if the pack (and the engineer I chatted to when I bought them) is to be believed and I clean out the holes properly then the bolts are likely to outlast the house.
Not sure how I’m supposed to remove them if I decide I want to, I suspect it may involve a very large hammer and chisel.
Three bolts would be better, the four-bolts configuration may be a human interface thing.