When it's time to plan your track, keep in mind that S curves are generally not friendly to smooth, reliable operations. Sure, they may look great in photos, but when the middle of an S curve is too short, it can cause derailments especially with longer equipment operating through them. One way to eliminate S curves on a double-track crossover is to position the crossover so that every route through it turns in only one direction. This can be done as seen in the photo to the right; this example was on one of the layouts displayed at the 2008 National Train Show in Anaheim. Keen observers will also notice that there is a curve a little further down the track that goes in the opposite direction, but there is a section of straight track between the two opposing curves to eliminate operational problems.