We have started in Portland every year except last year when we decided to start from Corvallis. But our buddy lives in the Salem area and since we're not doing it with him he's going to start from Salem. Makes sense eh?
As for transport, they use moving vans with blankets and pads to get the bikes back to the start, and large buses to get the folks back. I always had a great DH who came and picked us up and then drove out tired butts back home!