How much traffic is running between Lewiston and Spokane? Doesn't seem like there would be enough to justify such a costly addition. Don't forget the line to Lewiston passes UNDER Joso bridge, and where the two cross is a couple hundred feet elevation difference. Just upriver from Joso on the south side of the canyon is a very large deep canyon that would need to be crossed with a bridge that is almost equal in size to Joso for such a Joso to Lewiston connection to work. Putting the new connection on the north side of the river and running it up the Palouse River canyon makes more sense to me, since the Lewiston line crosses the Snake River within view of Joso.
Of course both of these options still don't make as much sense as say putting in a loop track at Ayer if run through operations Spokane - Lewiston are needed. In fact I'm pretty sure that is the most cost effective solution. But again is the need there?
Matt F
Moscow ID