Re: New, New, New .. Tacoma Passenger Train update
The route that Sound Transit trains take near (the Tacoma Dome) as they diverge from the BNSF main are former Milwaukee RR tracks, continuing over the new bridge and to the Freighthouse Square station. Just past the station, the former Milwaukee tracks continue as they earlier did "up the hill" to freight customers. However, passenger trains switch to newly built trackage that spans a gap between the MILW tracks and former NP/BN/BNSF tracks known as the "Prairie Line".
The end of the Prairie Line that formerly ran down the hill through (what is now a satellite University of Washington location) and formerly connected to the BNSF main near the Tacoma Union Station has been removed. The newly built trackage connects to the stub end of the remaining Prairie Line and continues on to Nisqually Junction where it rejoins the BNSF main to Portland OR.
So the bulk of the passenger bypass route is former NP Prairie Line, combined with small sections of MILW and new trackage.
WA state DOT project page is here: [
www.wsdot.wa.gov]