Connecting the yard tracks to the mainline tracks on a model railroad can be a confusing problem for some modelers. For this problem, like others in the hobby, it's often best to follow the KISS principle (Keep It Simple, Stupid!). This example, which was used on an HO scale modular layout, uses four standard turnouts, three small-angle crossings and one double-slip switch. With this configuration, it's fairly easy to tell which route a train will follow through the junction, and by using only standard switches and crossings on the three mainline tracks, it is much less likely to derail a train already on the mainline. One other thing to note with this configuration is that the number of S curves a train needs to negotiate to travel between the yard and the mainline are minimized, further reducing the chance of derailments through the junction.