I frustrates the hell out of me when an outsider says "oh they do it in Japan, Germany, Netherlands etc". Do we live in Japan, Germany, the Netherlands? Yet people continue to insist that we do things the same way without realizing or being ignorant of the fact that we deal with completely different operational & regulatory requirements than those nations. Your proposal runs into physical, technological, operational and regulatory constraints. Clearly your not affiliated with any of the major railways, otherwise you'd be cognizant of these limitations. Here, allow me to give you specific examples of them.
When there is a priority alarm, the CSA must cease all other duties an proceed to the coach where the priority alarm has been activated. If we are pulling into a station when it is activated, we will be delayed as the CSA must attend to the matter before we can proceed. Likewise if it happens when we are at the station or when we are just leaving the station, the train must be immediately be brought to a stop if still adjacent to the platform. The amount of delay varies depending on where the coach is located on the train, how many people are on the train and on that coach, since the CSA must walk through to the coach and then when in the coach he must ask anyone if they require assistance. The resulting delay can be negligible(eg. a false alarm in the CSA's coach), several minutes(eg. a false alarm several coaches away on a busy train) or a 1/2 hour or more(eg. medical emergency's, passenger disruptions). I have no idea how many alarms we get in a single day system wide but I can tell you that in one shift on one line, I hear an average of 3-5 passenger alarms being called in to operations. 90% of the time its a false alarm but quite often even those will result in delays. So why do they have these procedure and as a result incur so many delays? Perhaps its because GO values its passenger safety more than maintaining a schedule?
When a train strikes any object on the track it must stop and thoroughly inspected, which will resulting in about a 10 min delay. Why do we do this? Once again perhaps because GO values safety more than on-time performance.
When a wayside inspection system has not given us a proper reading must slow our train down and contact the dispatcher to get one. If he cannot provide us with one then we must stop and inspect our train. Resulting in a substantial delay.
When a wayside inspection system has given us an alarm, we must stop the train immediately and inspect it and make sure it is safe to proceed. Resulting in a substantial delay.
If there is a rule 43(slow order) usually only on one track in a given location, this can delay multiple trains. With another track available trains can be routed around the problem without incurring any delays at all.
In the winter or during the fall(due to snow/ice or leave residue respectively) heavily loaded trains can be subject to severe wheel slippage. Those who travel on the Lakeshore East line may have remembered the many delays that occurred several years ago to trains leaving Union traveling east to Oshawa. While the problem has been largely mitigated(it was so bad at one point the several trains stalled and had to go back to Union) I can assure it still is an issue. I fact it caused significant delays to multiple trains just a week ago.
Dealing with any foremen working on the line will can a huge issue more so when train frequency increase. Everyone has to communicate and receive verbal instructions which must be repeated back correct before being allowed to proceed. If we cannot communicate with a foreman, we cannot enter into his limits. Radio interference is a constant problem we deal with on a daily basis, be it other trains using the radio at the same time or simply a poor transmission. The problem is exacerbated when there are more trains in a given area. In addition
While they all individually might be infrequent, when taken altogether these problems and other less frequent ones (trespasser incidents, mechanical failures, signal malfunctions, rule violations, poor visibility due to weather conditions, police investigations - all of which I've seen happen multiple times per year) results in about 5-10% of all train movements being delayed by 5 mins or more.
That is why GO has chosen to design a system on the Weston sub. that will mitigate the impact to other trains.