Here goes the Salmon Creek Park and Ride by I-5 in Hazel Dell aka the I-5 Express:
www.c-tran.com/pdf/105route.pdf

Okay here's the map for the Portland city center:
trimet.org/maps/citycenter.htm
Should take MAX yellow line from Expo Center to PSU


And here is the whole trimet system for Portland:
trimet.org/maps/trimetsystem.htm


Another version that requires more driving on my own car:
I drive to the ExpoCenter via I-5, park there, and take the above MAX yellow line right to PSU.
That's an idea!
Anyways, I wanna ride the MAX! C'mon it is a train!!!
Here's the yellow MAX route ExpoCenter to PSU page