I'm mentioning it again, but I think it would be really good for the trackage around Union Station to be buried, from the Don River crossing in the East to where the Georgetown line branches off.
Burying this portion would do many, many things. First of all, it would open up a lot of development on land previously occupied by the rail corridor. It would also remove a big barrier from between the City and the waterfront. There would also be a lot of room to add extra track, enough for all of Union Station's future needs.
It would also allow a complete redesign of Union's platforms, which would probably and hopefully allow the station to be much more efficient, especially when handling Go Trains.
In terms of the DRL, it could hang on the north end of the underground tracks, probably do a duck out to better service West Don Lands, then pop back in to land right underneath Union subway station.
I think that burying even a small portion of rail around Union like that would be great. I sure hopes the City looks at doing that.
While I agree that would be quite the ideal solution, accomplishing such a task is quite the logistical nightmare and probably does not justify the costs.
In order to bury the tracks the current raised viaduct would 1st have to be removed. It would be extremely difficult to do this while maintaining even current levels of GO & VIA service nevermind the coming massive GO expansion plans which will be implemented well before any such a project is undertaken. Temporary tracks can't be built adjacent to the corridor because it's surrounded by developments to the north and Lakeshore boulevard and the elevated expressway to the south. Aside from rail traffic you have Cherry st, Parliament st, Sherbourne st, Jarvis st, Young st, Bay st, York st and the newly constructed Simcoe st underpass all routing traffic underneath the corridor.
Obviously you couldn't just rebuild it in one 'go' as that would shut down all those streets and all GO traffic on the Lakeshore East, Stouffville and Richmond Hill corridors and VIA traffic to Montreal & Ottawa.
Half the raised viaduct could perhaps be removed and temporally made level with the roads crossing underneath it. Doing this alone will lead to major train congestion during rush hour. As you would be eliminated the use of several tracks in a corridor that sees during the rush hour 12 trains come out of Don yard westward into Union station, several westward all day trains coming from the Lakeshore east corridor several more westward equipment trains coming from the Lakeshore East corridor, more than a dozen trains going eastward into the Lakeshore East corridor, 5 more trains going eastward to Stouffville, 4 more trains going eastward to Richmond Hill and several more VIA trains going in both directions as well. - It will seriously interfere and cause major delays to all the above trains. Not only because you have less tracks but also because of having all those workers and equipment down there.
So then what do you do with Cherry st, Parliament st, Sherbourne st, Jarvis st, Young st, Bay st, York st and Simcoe st? Will the tracks be brought down to be at the same level as these streets currently are? In that case the half the corridor would be made level and level crossings would be temporality installed at all the above streets, while the second part of the viaduct is removed. Of course this would level to massive congesting because a train would be crossing the tracks every couple of minutes doing rush hour. So then should the streets be temporality closed off entirely? Not really an option as this would lead to even worse congestion. Once the Viaduct is removed then overpasses could finally be individually constructed at each street. The cost would be in the billions and construction would last for many years.
A better solution would of course be to lower the first half of the viaduct that is to be removed to a level below all the streets passing underneath the current viaduct. This would be the more pedestrian friendly solution of course, and eliminated the need for bridge approach structures. But it would require deeper excavation of the track bed. Undoubtedly countless utility relocation projects would have to be undertaken, overpass structures would still need to be built at all the streets, drainage could be a major issue due to excavation below the water table. Cost would increase enormously as would constructions time, probably lasting over a decade.
Or you could just leave it as is. Is it really worth the exorbitant costs and years of increased congestion to both rail & vehicular traffic?