Train Type Operators is a collection of train types that each crew can operate on, e.g. freight trains with different dynamics (like load coal train and empty train to return which are likely handled by the same crew), and each crew is such one of the train type operators. In essence train type operators data tells which type of trains the crews are qualified, certified, and trained for. The time for a crew to get to a crew change point is determined by the distance between the train crew office (which are located near one or more nearby blocks) and the block the exchange takes place. Any crew is either on a train, at an office, or near an office when not on duty. Offices are responsible for assigning crews of one or more train type operators, so one can be responsible for urban intercity trains, and another only for freight trains. Station stops have been enhanced for stops to allow crew change only, not for passenger or load exchange. If a crew change is placed nearby the block for some reason, the station stop for the crew change is not necessary and therefore can be skipped.
And yes, all is still in development
