I cross road grade RR tracks on my route, and they always make me a little apprehensive. I usually swing wide and cross at as much of an angle as reasonably possible. They run parallel to my line, so 90 degrees would require slowing way down. Usually cross at about 45 degrees with a good grip on the handlebars and a little lift of the front wheel. Saw a guy go down hard on them once and asked if he was OK, but he was too embarrased to even respond.