Ok, next bridge up is another pedestrian one, the rather ugly 70s concrete one over I-5 at the Barbur Transit Center. I hadn't really planned on doing a post about this thing, but I ran across it while taking photos of Tapestry, a large mural along the Barbur-side approach to the bridge. I figured I was there anyway, toting a camera, and it was technically a bridge, so sure, why not? A PSU study of local pedestrian bridges notes this was built in 1976 along with the transit center itself. The study notes that many neighborhood streets on the other side of the bridge lack sidewalks (a common problem in SW Portland), so it's not part of a wider network of safe bike/pedestrian routes. I'm not sure that's something city planners even considered back then, and I'm not entirely sure this area was within city limits back in the 70s. Until the late 70s & early 80s large portions of Multnomah County outside the central city were unincorporated, and the county didn't really bother with things like building sidewalks or a proper sewer system, keeping people from building in flood zones, maintaining a useful park system, little details like that.
I didn't see much of anything in the library's Oregonian database about the bridge itself, but I did run across a September 12th, 1976 article with architectural drawings of the proposed "West Portland Transit Station". Barbur was the city's first transit center, as it turns out, and apparently this was a new concept imported from Toronto that other US cities hadn't adopted yet. So, little piece of history here. Though it seems like they hadn't quite perfected the concept, given the center's ugly 70s shelter, which looks rather cheap and dilapidated these days. The article mentions that the transit center was about 92% federally funded, since it's next to an interstate & qualified for money, I suppose because TriMet buses still ran on freeways in those days. A later October 28, 1979 article (which I seem to have misplaced the link to) describes major vandalism problems at the still semi-new transit center. Neighbors said they avoided the pedestrian bridge due to burned-out lights and broken glass. TriMet had even installed security cameras to keep an eye on the place (which was an unusual step in 1979), to no avail. There's probably no easy way to know whether the rate of petty vandalism has dropped since the 1970s. It seems to me, anecdotally, that it has, but I have no actual evidence to back this up. TriMet might have internal numbers on how much they spend each year repairing vandalism, and maybe a count of reported incidents, but I haven't seen that info reported publicly. Assuming my guess is correct, you might be able to chalk this up to the wider national crime wave of the 70s & 80s, which in turn has been blamed on various factors ranging from long-term macroeconomic shifts to the use of leaded gasoline. I've also seen a proposal (which I don't have a reference for at hand, unfortunately) that certain architectural styles tend to promote vandalism. In particular, as the idea goes, people see things made of ugly grey concrete and are instinctively driven to damage them. The idea has a certain poetry to it, but I have no idea how you'd go about proving it. The transit center & bridge haven't gotten any prettier since 1976, so if they aren't getting vandalized like they used to, that would tend to disprove the "architecture rage" idea.