I find the way passenger rail in the Northwest of the country is casually sidelined at the drop of a muddy hat to be rather curious and perplexing. This complication doesn't seem to be getting better over time either. Which makes me wonder if passenger rail is simply a bad match for a region where it can and will be repeatedly abandoned and embargoed over and over for months on end.
There's a complication which perhaps isn't entirely obvious here. The thriving passenger rail route is Seattle-Portland, and there is pretty loud outcry on the rare occasions when it is embargoed. (It does have a few segments with occasional mudslides, but it's pretty uncommon.)
(You'll notice that the culvert failure between Tacoma and Olympia was repaired fast and trains were running the next day.)
Most of the mudslides, however, are *north* of Seattle on the Seattle-Vancouver, BC route (also used by the Empire Builder for Seattle-Spokane). The political climate between the US and Canada turned chilly in 2000 and hasn't thawed out since then. This accounts for the toleration of these embargoes.
I seriously doubt that for all sorts of reasons. It is baseless conjecture.
First, the main passenger train impact from the closures of the the slide prone stretch between Seattle and Everett is not Amtrak, either the Cascades or the Empire Builder. It is the Sounder commuter trains. Local news stories about the closures and slides are always about the impact to the Sounder service. They usually mention Amtrak in the last paragraph of the story as something like "Amtrak service to Bellingham and Vancouver, BC is also suspended." Amtrak impact is a footnote, service to Canada even more so.
WashDOT is helping to fund the slide mitigation measures partly as measure to improve the service on the Cascades (which they fund), but in large part to improve the reliability of the Sounder.
With regard to the Cascades, I ride the Cascades fairly often. Not everyone on the Cascades north of Seattle is going to Vancouver. I don't have statistics, but I see a LOT of passengers bound for destinations short of the border, particularly Bellingham.
BNSF's motivation is primarily CYA to mititage liability exposure from mudslides. When the slopes get saturated and unstable, there are often multiple slides in the same location. The frequency of mudslides in the stretch is a combination of somewhat naturally unstable geography (those bluffs are not exactly granite), coupled with some poor drainage engineering in the developments on top.
The mitigation measures have been pretty successful. There were comparatively few incidents last year compared to some earlier years (really bad year was 2 or 3 years ago), when slides cause the line to be closed to passenger trains more than it was open. The severity of that year is what caused the state to start funding mitigation.
Finally, while mudlslides are more frequent in the zone just south of Everett, they are far from unknown on the line south of Seattle. The about-to-be bypassed stretch around Point Defiance is a culprit, as is an area near Kelso around Castle Rock.
