Report: Trolley driver has long history of speeding infractions

The signal that the train Quinn hit was stopped at is the last 'regular block' signal westbound prior to the switches entering Park Street. It was converted from an automatic "green yellow red" signal to a red "absolute stop before proceeding" signal about one month before the crash.

And yes, the dispatcher was 'short turning' a game extra at Park Street at the time of the crash. However, had the signal in question not been converted from automatic operation to absolute stop, the train would have been one block closer to Park Street, meaning that Quinn may have had more time to react and, thus, might not have hit it at all.

The train was stopped at signal 746, which is the last red/yellow/green signal. The signal you're thinking of is signal 748 is the stop signal, which is the last signal before the switches at Park St. Even if the dispatcher had short turned a train, the Cleveland Circle train would still be allowed to enter Park St. on the opposite track while the train was short turned. However, you cannot assume whether or not he would have avoided collision if the train were a block further away. Perhaps he may have been more engrossed with his phone.

If it is determined it is necessary to use the signaling to enforce speed restrictions (for curves and entering stations and the like), the established and proper way to do this is with what is called in the transit industry as a "grade and time" signal. In such cases, the signal is normally kept at red, but is connected to a timed track circuit. If the approaching train is moving at or below the maximum set speed for the restriction, the signal will change from red to yellow. This minimizes delay to trains, and also preserves the safety aspect of a red signal - i.e. there is an actual obstruction you should stop for.

Grade and time signals are hardly new technology either - the first grade and time signals were employed on the New York City subway system when it first opened in 1904. And the wiring and labor to convert an automatic block signal to grade and time is exactly the same as to convert the same signal to absolute stop and proceed.

Almost all of these signals are in fact "grade and time" signals, with the exception of the signals prior to Boylston. If the operator were to actually slow to the posted limit, they would receive a permissive aspect by the time they arrived to the signal.

For the record, the NTSB report on the Quinn crash, apart from noting the signal aspects at the time of the crash and indicating there were no observed defects in the signal system, made no commentary on MBTA signal practices or protocols.

Actually, yes they did. They came to the conclusion that had there been a PTC (positive train control) system in place, there would be a drastic reduction of accidents. But with a PTC system in place, there would be reduced capacity in the central subway.