You are right, designing a perfect system is complicated. Of course, you have account for planes that are expected to leave the runway before the next touchdown

You are right, designing a perfect system is complicated. Of course, you have account for planes that are expected to leave the runway before the next touchdown. The train equivalent for this is called CBTC. https://en.wikipedia.org/wiki/Communications-based_train_control https://en.wikipedia.org/wiki/Communications-based_train_con... My bigger point here is that there are a bunch of low-hanging fruit that could have prevented this. A system doesn't have to be perfect to be useful. The tower could have known, that a plane was expected to land in the next 30 seconds. They could have automatically transmitted that to the cost guard plane and this could have sounded an alarm in the cockpit of the taxiing plane.