This is not something you "buy"..... it is a "method" that you make on-site, with manual labor.
Here in Central Florida, that type is very common on our roads because the
signs are often clipped off by careless drivers.
It is easy to pull out the "remnants" from the broken post and install a new
sign without a lot of effort. The "wedge" keeps it secure in the hole.
Very easy installation. Once you do a sample in your own yard, you'll work out the kinks and find your comfort zone. The only issue in placement is that you ensure the correct orientation, IF it is a square hole to accept the square tube
sign pole. Of course, if the pole is round, it doesn't matter, as long as it is "plumb".
Edit: I don't have access to the exact specs for my area, but from what I see as a bystander looking in, this is how I imagine the base to be built. The
sign post being used will determine the size of the "socket". It must fit a little loose to accept the "wedge". All should be specified in the engineer's instructions.
Is this project on private property? The designer, architect, engineer, U-DOT, etc should give you the
specs for the "socket" that stays in the concrete. It could be aluminum, steel, or PVC. The "wedge"
can also be wood, plastic, aluminum, etc. The ball is in your court to give the customer what he wants.
Here in my area, I've seen them round and square - it depends on the structure of the
sign post.
