I cross over the Tram tracks in Croydon every day on my commute, at one place at an acute angle. I keep waiting for the day when I'm a bit tired and dopey, don't concentrate enough on things, and then come a cropper.
I think this problem with tram tracks is simply unfamiliarity.
When I was young tram tracks were commonplace in most big towns and barely raised a comment.
That was my problem, a mile before the end of my first (and so far only) 30 miler, tired and starting to knock a bit, its easily done.