> You could put a TCAS on every ground vehicle. It's not rocket science.

TCAS on planes is disabled below 1000±100' (~300m) AGL (above ground level).

ADS-B on vehicles is already a thing (and FAA certified):

* https://uavionix.com/airports-and-atm/vtu-20/

There are three categories of runway incursion types: operator/ATC error, pilot error, pedestrian/vehicle. Even if someone 'knows' that they need to "hold short runway 12", they can still have a brain fart and go through the hold short line.

Unless you want to argue that all vehicles taxiing have to operate (SAE Level 4) autonomously?