On the Cabling tab, in the Cable Tray group, click Route (Alt+T). Start the routing from the specified location with a suitable context-menu command. Before routing, consider the following guidelines: Cable tray lines are continuous, consisting of interconnected straight cable tray pieces and. maintain spacing or to keep cables in place when the tray is ect the minimum bend ra-dius for cables as they exit the bottom of the cable tray. The Cable Tray system is installed in electrical rooms, plant rooms, and service corridors. Not respecting. Most projects are roughly defined at the start of cable tray design.