As to railroad right-of-ways, they will only let you within 30 feet of
the tracks, which is still in the ror. It is safer than anywhere else
because of the difficulty of getting permits to dig in railroad ror (5+
years here in Washington) even for other utilities. Some idiot with a
backhoe can still be way of target though and get you. Derailments and
floods are also big problems in rr-ror. The only real protection you
have is ringed SONET, however, even in that arrangment some carriers do
not have the ability to reroute everything, just the priority stuff. So
they'll still have outages. It's all a matter of capacity and what
electronics they use.
<lurking mode off>
Previously, the telephony industry has had a surplus of fiber. But since
the Internet has taken off, much of that excess has been taken by
dedicated Internet customers, and expanding POP sites. Now,
many facilities-based carriers are having to lay new fiber to meet
the unending demand. Perhaps the fiber cuts we are seeing are
more often related to construction of this new fiber, and not freak
accidents (farmer joe and his shovel). If so, then no matter where
you run the fiber, if it sits next to existing fiber run, you run the risk
of new construction accidents. In effect, the backhoe in the above
example will be "targeting" the fiber already in the ground.
@USLD Internet Services
The views come from me and are mine, not USLD's.
<lurking mode on>