I am alarmed at the high number of supposed engineers on this thread that are seemingly unaware of how safety-critical systems work. Literally every other piece of this system has redundancy built into it. Robustness is never optional in a scenario involving human safety.
When did this lunacy become an arguable position?
I'm not in aerospce field, but surprised how low-tech and critical to human error takeoff/landing/taxi process is.
We have TCAS/ACAS in air, but no similar automatic safety guards near/on the field?