If you have a map of all utility poles you could probably just avoid every straight line between any of them within some reasonable distance of eachother.
it's an approximation of dangerous areas, catenary curves are more accurate than straight lines but you don't know the length of the cable so you don't know the droop height.
Telcos are notoriously secretive about the location of their fiber. They even got most state legislatures to exempt it from state-level FOIA laws.