Been trying to understand what this issue is with running the fiber in existing utility conduit - specifically on 9th Avenue (i.e. between Judah and Pacheco) in the Inner Sunset of San Francisco. As a property owner, I had to pay when utilities were installed underground. It would seem to me that access to the conduit should be universal or shared - also realize we are dealing with entrenched interests and bureaucracy.
It would seem that way, but unfortunately it's not. You were required to put in conduit, for three companies: PG&E, AT&T and Comcast. (Oh, and probably water, sewer and gas lines too). That's it. This is a holdover from the days of monopoly telephone service and a single Cable franchise.
The solution is for cities to adopt a "Dig Once" policy, that assures that when development and undergrounding occurs, there is conduit which is available for additional companies beyond these. And while SF does have a Dig Once policy, we haven't seen it working well, and SF seems unwilling to enable competitive deployment, with no allowance for commonly used trenchless construction methods like microtrenching or even commonly used directional boring.