The single-tracked CN mainline from Washago to Bloomington Station (Richmond Hill) is a major bottleneck in its current form, so each additional train does have a noticeable impact on the overall line capacity. In that 97km segment, there is currently only one siding that is long enough for CN's transcontinental freight trains, the 12,000 foot Brechin East siding. The rest are less than 7000 feet long, so they could be used to make a passenger train wait for a freight train, but they cannot be used to let a long freight train wait for a passenger train - it literally wouldn't fit.
View attachment 722004
Lengthening some of the sidings (e.g. Zephyr), or even adding a second segment of double-track (between Zephyr and Pefferlaw) may be necessary if we want to increase the Northlander service above one train per day while actually operating a somewhat punctual and fast service