There is a CP Rail corridor through the city and at one point long ago the CP Rail's North Toronto Station, now an LCBO just south of Summerhill subway station, was a place people could catch trains to places across CP's Ontario network reaching as far as Detroit and Montreal. The station however couldn't match the convenience of Toronto's Union Station and still can't to this day.
With the Crosstown Line on Eglinton just about to open and with all the other network enhancements that will make the area easier to get to, there isn't an immediate need to cover the expense of moving CP's freight line north of the city to free up this line for passenger use. However, things will not stay the same and while Union Station may be more convenient to connect through and closer to where more people want to go today, it's capacity is not infinite. At some point, with all indicators being that Toronto will continue to grow, the Toronto North Station will likely see passengers once again. If there are unforeseen freight service related obstacles preventing the Valley Line and Alto high-speed rail service being implemented as planned, that day may come sooner than expected.
The Ontario Line as proposed in this plan is a loop, however in designing this plan there was no priority given to creating a loop. The Ontario Line became a loop because step by step plan build out trying to balance between serving cores and hubs, serving new areas, finding fast and direct paths between points, and using what already exists as the starting point led to this plan.
The goals that lead to the creation of the Ontario Line Loop are:
treating major urban centres and Pearson Airport as major transportation hubs and planning direct connections between the neighbouring transportation hubs,
using what already exists as much as possible to build the network out, and
reducing the need to transfer by having through services rather than two routes that both terminate at the same place.
With the Ontario Line, already under construction, terminating at Exhibition in the west, the nearest urban core to the west was Etobicoke Centre, so that is where the line goes. At Etobicoke Centre the choices are Mississauga Centre or Pearson, but Line B already goes in the direction of Mississauga so the next portion of the line heads towards Pearson. At Pearson the nearest cores are Brampton Centre or Vaughan Centre, but Line C already serves Brampton, so the next segment of the line heads towards Vaughan. In the east the Ontario Line as being constructed ends at Don Valley and the nearest centres from there are Midtown, Gateway (Langstaff/Richmond Hill), Markham, and Scarborough. Line 5 is already heading west to Midtown, east towards (but not directly to Scarborough), Line B is passing through the area headed to Gateway, so Markham remains as the optimal routing.
The end result is that these transportation links evaluated independently come together to form a loop, and that having services continue in a loop will reduce transfers. The line being in a loop doesn't force all trains to go around the entire loop and the northern part of the line is being built last accepting that demand will not be the same in all places. The line being a loop doesn't suggest that people will find value in riding around the entire loop, however it does mean that if you are in Vaughan Centre and heading to Etobicoke Centre, or in Esna Park headed to Concord, you are better served with through service than you are without.
The symbols used in the system and line maps and well as proposed signage will give users of the system an indication of what service frequency can be expected at a specific station on a specific line. The service categories are "Urban", "Suburban", Regional", and "Limited".
"Urban" service, denoted by a circular shape, indicates a very high frequency service of every 10 minutes or less except late at night. Users of the system should feel comfortable showing up at these stations to catch a train, subway, or LRT at any time between 6 am and midnight without planning ahead.
"Suburban" service, using a square shape as a symbol, indicates an all-day service that runs at a frequency of every 30 minutes or less excluding late at night. Travelers planning to use suburban services should understand the schedule before starting their journey to minimize their wait times but don't need to plan ahead.
"Regional" service, using a diamond shape (tilted square) symbol, represents an a service that runs many times throughout the day at a frequency of every 3 hours or less. Travelers can count on this service getting them where they need to go, but should plan ahead because a large portion of their day could be wasted if they don't plan their day appropriately.
"Limited" service, symbolized with an inverted triangle, represents a service that runs only on certain days and/or that runs only at certain times of day. This provides a more infrequent service to meet peak demands on routes that under most conditions are easily managed with busses but during peak periods need the extra capacity of a train. Typically limited services meet the demand for things like morning and evening commutes, special events, and weekend/holiday rush.
This plan is focused on the Greater Toronto Area including Hamilton so routes in the Kitchener-Waterloo-Cambridge-Guelph triangle are not specified in this plan. However, it seems obvious these cities will continue to grow and require more transportation options within and between these cities.
While a detailed approach to improving public transit in this quad-city area was not studied, it is recommended that Grand River Transit, Guelph Transit, and GO Transit work together on an integrated network between the three systems. This integrated system should handle local, high-volume, and rapid centre-to-centre transportation with seamless transfers and an integrated fare system. An LRT link from Kitchener to Cambridge handles higher-volume and a rail link between Guelph and Cambridge provides rapid centre-to-centre transportation but combined doesn't provide a real plan focused on getting people conveniently where they need to go.