I'm setting a goal to have all of the track replaced on the South side of Chicago in Trainz 2022, by February 2024. That will give me about 20 weeks to do several hundred miles of track in:
BNSF Corwith Yard
BRC Clearing Yard
UP Yard Center
CN Kirk Yard
NS 47th St Yard
CSX 59th St Yard
CSX Barr Yard
IHB Blue Island Yard
IHB Gibson Yard
CN Markham Yard
and all of the mainline, siding, and industry tracks