Hey Alex,
I keep going back and forth on this one - at first glance it feels right and there's even lane markings and a yellow sign basically saying "bikes onto the sidepath please"... 

With that said, the wiki (https://wiki.openstreetmap.org/wiki/Tag:bicycle%3Duse_sidepath) states "This tag should only be applied in countries that have compulsory cycleways." I'm not 100% sure that biking on that side path is absolutely legally mandatory here - Oregon law famously states that it's explicitly legal everywhere except a few pieces of the interstates and Hwy 26. 

Thinking that maybe a good compromise would be to keep your bicycle=use_sidepath but to add cycleway:right=separate just to make it real clear to any software trip planners.

What do you think?

George
rothg@trimet.org