General Road and Highway Discussion

[timio]

Here's one fairly intensive solution (if even plausible):

Close Lancaster for 2 years
Add a third track to the north at a lower elevation (perhaps only a few feet lower than current) going right into the yard from the west
Once the third track is active, lower the middle track to ensure safe passage of through train traffic
Once the second and third track are active, lower the southern track
Build the overpass for traffic on Lancaster at a lower elevation than would have been required

Benefits:
Grade separation
2 tracks cleared for through traffic with a third yard-specific track
Ready for HSR / GO RER / future expansion.