I'm not sure if you were only referring to the Barrie line, but work is definitely underway on the Stouffville line. Workers are widening the area for the track under the 407 bridge (well, the sections on both sides between the two separate 407 bridges) and running gas (and power?) just south of the bridge, which I assume will be for the switches for the passing track? I'm no expert, so if the work underway is something else, someone please correct me.
I saw this morning that bundles of cross-ties have been placed in the hydro corridor just south of the 407.
They're definitely moving ahead with double tracking that section.
They could, IMO run two trains to provide hourly service from Union to Unionville back and forth as it only takes 15-20min from Unionville to the Scarborough Station.
The trains would ideally pass each other at Scarborough station where there are 3-4 tracks as part of the Lakeshore East expansion.
Negitive.
Nothing is being done to widen the track under the 407. The work that is going on at that location is for a new bridge being built for the 407 widening.
Work being done at the Hagerman underpass is for a fiber optic cable being laid. New tracks are simply for replacement of the old tracks.
All day service on the Stouffville line is to extend to Mount Joy and not to Unionville. In either case there is no need for double tracking the line in that area. Because with an all-day service (hourly or less frequent)
trains won't be meeting each other at that point.
Mount Joy is 38.7 km from Union
making all stops from Mount Joy to Union takes 49 to 54 minutes.
The half way point time wise to Union is appox. when trains are going under the 401 bridge.
Unionville is 30.6 km from Union
making all stops from Unionville to Union takes 35 to 38 minutes.
The half way point time wise to Union in this scenario is just before Kennedy station.
If they were going to build a passing track it would have to be at one of those locations. And thats only if they are going to use 2 trains, they may just begin all-day service with one train as they do it now on the Gerogetown line. The most frequent service that would be provided for on the line would be hourly. This would require two train on the line at the same time and hence at a minimum the passing tracks at the above locations.
This all day service will run in-between the last train down in the morning and the first train up in the evening. Because under the current method of control for the line - OCS(non-signaled track), it would be
extremely complicated and difficult to maintain any type of schedule while operating trains in both directions at the same time. Trust me, its hard enough run it on schedule with trains going to same way using that system lol. Now of they were crazy enough to try and run a reverse peak all day service on the line, then maybe you could use a passing track at that locations. But you'd still have to first build a passing track at one of the other locations that I mentioned. (I believe that they should two-track the either line, but thats another argument for another time...)
However I don't believe that Transport Canada will allow them to operate a two-way all day service with high speed passenger trains with that frequency and carrying that many passengers in OCS territory anyway. Simply because of the inherit dangers of the system.