> Really? The BLE started bringing it up in the early 1990s when it was just a white paper after a couple collisions in the PNW where the crews were suspected of falling asleep and running signals. It's been their go to excuse for almost every collision since. They didn't have the brains to realize that PTC would eventually provide the basis for reduced or crewless trains.

OK, let's see now. In the 1990s, particularly the early 1990s, alerters were still viewed as a pain in the neck, by both labor and management. There would be an accident, and the NTSB gum flappers would make a bit scene about "obsolete signal systems" and enforcement of restrictive indications, which the 1920s era cab signals have been able to do if the operating company bought the extra apparatus to do so. At the time (1990s) the BLE was interested in was making operable alterers (and accurate speedometers) mandatory. The 1920s era cab signals, which are still in use on the NEC, didn't turn out to be the panacea that everybody hoped because the capital invested didn't produce acceptable returns in accident reduction.

On the other hand, perhaps you're confused with Clarence Monin's "last man standing" principle where the last crewmember in the cab would the the engineer, represented by the BLE?

PTC didn't come in until after Sanchez's wreck at Chatsworth in 2008, and with PTC, just like the 1920s era cab signals, you can still have a collision at restricted speed.