The Troutdale Bridge over the Sandy River is still single track. Actually leaving the siding intact on the east side of the bridge instead of a continuation of double track is more versatile. Lets say there are two westbounds coming into Troutdale and they are both heading for the Kenton line. The first is a MHKFI and the second is a KG1SE. Obviously you want the hotshot to be first on the Kenton Line. But you also have eastbounds on both the Graham and Kenton lines. So you stuff the MHKFI into the Sandy siding and the eastbound off the Kenton Line into the Troutdale siding and hold the other eastbound on the Graham Line. And the KG1SE sails by the whole mess.