I don't think it's much, if anything, depending on the location. My understanding is it's governed by public use policies, since it's public infrastructure. I do know it requires some work for those putting more infrastructure on there to figure out the new load and stress and submit plans for required work, and sometimes poles are identified that are degraded to the point that it requires replacement or retrofitting, but I can't recall whether that's a burden taken by the public utility, the company looking to utilize the space, it's shared, or it's situational and depends.

> I wonder if the trenching style deployment also has some sort of agreement with the city?? Whenever I do see the trenching teams installing fiber lines, I'm always curious why such a small amount is being installed.

You do need to get permits in both cases. I think microtrenching is easier to get permitted because it causes less issues with the road. You're cutting a line an inch or so wide, so there's less worry about car tires compacting the filling material and making the road bumpy. Since it's deep but not wide, it could also be they're stacking multiple runs one on top of each other, which at any one point in time may look like a very small amount being inserted (I don't know, not my department).

> Every connection needs a pair, so how ever many strands are in that "cable", there's half that number of connections.

Depending on what you mean by "connection", they don't. Fiber strands are split out with optical splitters, one or more times, so a single strand back to the CO can handle multiple actual installation locations (but not too many). Planning out how many you allow generally and how much you'll allow max is a balancing act. Sometimes you deliver to a building with multiple units and you don't want to drop a line to every unit but you don't want to serve twenty units off a single strand that might be split once upstream already).