Well, last time I did that hitch was with my friend Kate. We tried to get a NBD train outta Eugene but got tired of waiting after a day and a night and just went to HWY 99 to hitch. We got a ride to J.C., walked the couple miles to Harrisburg, walked out to the road to I-5 and got picked up after a couple hours and driven to the 5. After about 30 minutes at that desolate onramp in the middle of the fields we got picked up and taken to Tualatin which was a sweet ride.
Hitching out of Eugene on I-5 would have been way more direct, less walking and probably less waiting. We still did it in half a day but that one ramp by Gateway mall in Eugene would have probably made that into 2-3 hours to PDX instead of 6. And if you want to get the most miles out of your public bus ticket before hitching you can take the LTD bus to Coburg which is about 10 miles north of town.