Metrolinx quietly slipped a major change in its joint Lakeshore East / Ontario Line corridor plans by way of a web page update with no accompanying announcement or explanation.
Metrolinx plans to raise the existing GO Transit tracks by 0.9m to 1.6m in order to increase clearances under bridges on the corridor. The west and east limits of this work along the corridor have not been announced, and there are illustrations only for the area north of Queen Street.
The previously published layouts assumed tracks would stay at the same elevation as today, with the new Ontario Line to the west and north of the GO corridor at the same level. The new layout shifts everything higher. Note that the top drawing here is a cross-section where the Metrolinx right-of-way is at its widest with open space on either side buffering the mass of the corridor.
There are significant challenges in this scale of work on a busy, live rail corridor. One does not simply bring in loads of fill overnight and jack up the tracks. Bridges are a special concern particularly in any location where all tracks occupy a common structure rather than separate spans for each track that could be individually replaced or raised.
I posed a series of questions about this to Metrolinx, but they will not be responding until Monday, June 21 at the earliest.
- When was the decision made to regrade the rail corridor?
- Why is this being done?
- What is the extent of the work, ie between what locations will the track be raised from its current level?
- By how much will the track be raised?
- What are your staging plans for maintaining GO service during this work?
- What are the effects on the bridges in the affected area?