Trains 507 and 509 go from Seattle to Eugene. Train 500 goes from Eugene to Seattle. Train 504 goes from Eugene to Portland. Passengers wishing to continue on to Vancouver (WA), Seattle, and points in-between must wait 40 minutes in Portland and then board Train 506. Why is this? Is the same trainset used for both 504 and 506? Or does the set used for Train 501, which arrives in Portland at 11:00 am, become 506?