If nothing else they need to hold up in every weather and temperature big airports exist (-80ºF to +150ºF) and get run over by airplanes all day. Already that's a non-trivial problem.
The costs add up quickly.
The US doesn't have horizontal directional drilling rigs that go under a runway and pull cable?
Even then, things occasionally go awry.
<https://en.wikipedia.org/wiki/Lake_Peigneur#Drilling_disaste...>
For an airport, the precision required both to not hit extant underground infrastructure and to know precisely where your newly deployed infrastructure is (for the next guy/gal to worry about) is probably a salient concern.
I'm not sure that horizontal drilling offers that degree of precision and assurance as opposed to rip-and-dig methods.
Any references / sources on that?
As opposed to the alternative described, where you close down the runway, dig out a full trench, lay a cable in a conduit, and attempt to compact every thing back to how it used to be?
You think that's a better alternative than just drill core'ing the conduit through?
Interesting.
787 wingspan is 200ft (60m). Planes don't turn on a dime either, but the larger ones do have steering linked to the rear wheels, so their turn radius can be surprising.
The non invasive solution would be to require some kind of ground control computer link that can directly draw their controlled path for them on their displays and give them a nice loud master caution or warning if they're about to break their assignment.
Then we can start thinking about ground autopilot systems.
Back in the days of the Exxon Valdez tanker incident, I wondered if the technology did not exist to positively track such major asset positions/directions, and dispatch an alarm from one or more authorities at a distance.
In terms of powering lights/signals, perhaps solar, batteries and a generator for each patch, and if there is no flashing of light visible (indicating power-loss or stuck-at failure), tower clearance must be given?
The lights don't need to be tall enough that the wings would be able to hit them.
And no one chooses when or where that is
If the norm becomes (radio clearance and no red lights), I suspect pilots will become conditioned to equate no-red-lights with landing clearance. Not 100%, but maybe at least 1% of the time. So if that happens and the red lights stopped working, you have a problem that wouldn't have existed if the red lights were never introduced.
Perhaps a more resilient system would use green lights to indicate landing clearance. Then if the lights failed, the default would be radioing ATC for guidance?
(I have no qualifications on this topic. I'm just guessing based on a bunch of Mentour videos I've watched.)