I have a love/hate relationship with railings. There is a sense of satisfaction from landing a good rail precision that just can't be matched by the same jump on a wall. Sure, I've got chunks of my legs missing from when we've had a disagreement but rails are one half of the Traceur's bread and butter so can't be ignored. If you are just starting off in Parkour let me reassure you - rails are awesome. They seem to be 'stickier' than walls, can still be balanced when wet and have more opportunities than walls. Don't get me wrong, I love a good wall too, but you can't underbar a wall (although some people have tried accidentally).  There is one hazard to look out for - the wobbly railing. Check each rail before you jump on it the same way you should check every surface you are uncertain of. However, a bit of wobble adds more of a challenge to a rail balance. It's worth spending some time drilling rail movements as it will pay off in your routes and challenges. Rail balancing and precisions just can't be drilled enough it seems. For this reason I would recommend balancing every rail you pass on your way to your training spots. There's no point in just walking past... Anyway, I'm not sure what my point is apart from, uh, yeah, railings are cool. Embrace their metal goodness and profit from their trust. Just don't ever become too confident because they bite.