Zonal distributed systems also help reduce ship design complexity by limiting the number of distribution elements that cross a space without servicing the space. In zonal distribution systems, only longitudinal mains run for fore and aft. Feeders generally run port or starboard and up or down. By careful location of the longitudinal mains, perhaps even using dedicated utility trunks, the number of spaces that must be “crossed” to reach the end user can be minimized.