I've never done the NP grade on the west slope of Lookout Pass. But a couple of years ago, on our way to the Hiawatha Trail, I decided to exit I-90 at the summit of Lookout and drive (more like coast) the NP grade down the east slope. I would say 4WD would not be needed, but good ground clearance might be advised if the roadbed hasn't been graded after the winter thaw. When we drove through the tunnel, it was deeply rutted in spots and I had to keep my SUV riding on the humps to avoid becoming high centered or tearing any vital goodies off the underside. Outside the tunnel, the roadbed was as smooth and solid as the access roads on Cajon in summer. However, judging by the photos in this person's account, the tunnel does have its better moments:[www.ingrs.com]

Now, as to the original point of this thread, without going into great detail, I can say that from what I've been seeing and hearing over the past few weeks, both the BNSF Hi Line and MRL are getting VERY congested. Heavy snow and severe cold haven't even arrived yet, but there are already instances of trains getting dog caught or tied down far from terminals, long back-ups of several trains waiting their turn through the cloggage of Spokane or the fuel pad at Hauser, etc. In addition to the grain rush, this is also the time of year, even in this questionable economy, when intermodal picks up, and we begin to see Z, Q, and S symbols with origin and/or destination points that are normally not seen the rest of the year. Coal shipments to Centralia and Boardman become a bit more constant when the lights and electric heat of Puget Sound and Portland get more use during fall/winter. As for areas of constraint, there are still portions of the Funnel that have single track (most notably the Sandpoint bridge), and even the two main tracks through Spokane become a parking lot when there's a flood of WBs trying to cross Latah Creek Bridge against a fleet of EBs coming in from Wenatchee, or when an EB Z train stops to work the trailer ramp at Parkwater. It's worth pointing out that when three or four WBs get stacked up in Marshall Canyon waiting to get onto the single track at Lakeside Junction, they have been known to hold WB grain or coal at Sunset Jct. rather than having such heavies move ahead and stop on the 0.8 percent around Overlook then try to get going again when the logjam breaks. Three other choke points in this region which have no easy fix are the 7-mile Flathead Tunnel in NW Montana, the nearly constant reverse curvature in the Kootenai River Canyon on the ID/MT border (roughly ten miles of which is single track, 30mph, and prone to rock and snow slides), and the slow and twisty single track through Hatton Coulee between Cunningham and Connell, WA.