Now that I know what types of cable trays are available, what configurations are available?

• Straight sections are available to route cables in a horizontal or vertical plane.
• Fittings are available to route cables in various
  directions in either the horizontal or vertical planes. Typical
  examples of fittings include elbows, tees, crosses, and risers. Each of
  these fittings are available in various radii and bend angles.
• Covers are accessories and shouldn’t be in here unless splices etc. are included.

Source: Cable Tray Institute (CTI)