Here's a "what is it" about a feature in a road, as I spotted this metal area near an intersection and wonder what it was designed to do.
for guesses based on the shape and size, I've speculated that these were for weighing the axle passing over them, or raising to block traffic from that lane, or, for holding a partition of wall, again, to block traffic from that lane, but only to prevent the blocks from being pushed out of alignment and position
Those are pressure plates -- now obsolete (superseded by the inductive loop wires set into grooves in the pavement). They were mechanical switches activated by the weight of vehicles that notified traffic control timers that a vehicle was present. Very solidly built, they often were not removed after the more-reliable inductive loops were installed.
ReplyDeleteoh wow! Thank you!
DeleteI gave up that anyone was going to answer this!
What are you doing looking back in the archives? It's rare that anyone looks at more than a couple days worth of posts!