you get the red line of lights on your right and surely that would prevent traffic from lining up on taxiway A?
Only if you look out of the windscreen and notice it!
That's the problem. In a digital age you expect to get a horn or an alarm if something is amiss. Unfortunately airports are still analogue, so you need to train crews not to depend upon a digital warning but to be aware of the analogue reality of the real world outside the comfort of the flight-deck window.
It doesn't matter how many horns and klaxons you stick in the cockpit, the reality is outside. And if crews don't look there when they are operating in the analogue airport environment then they are never ever going to see the blatantly obvious (see quote above).
You can only build so many fail-safes into a system but "the blind idiots" are always going to beat you. All you can do is weed them out to make life safer for everyone else.
Harsh - yes
True - you decide