I'm fairly new to Seattle, and wasn't around when I-5 Collonade park was built. It's clear that the park has seen better days, but the bones of a really incredible bicycle skills park are still there. Most of the beginner features are rideable, though berms and rollers are pretty washed out. Because the wood features are protected from rain by the highway overpass, most of them are still solid. Some clipping and grooming has been done recently, and the park looks generally pretty clean. Most of the advanced/expert features are in need of serious maintenance - Look before you leap!