tridem

plural tridems

1. An arrangement of three objects arranged one behind the other.

   The State bridge formula allows 42,000 lbs. on a tridem axle on non-Interstate highways.

   2015 May 28, “Appendix A: State Truck Size and Weight Laws”, in Anthony R. Foxx, editor, Compilation of Existing State Truck Size and Weight Limit Laws, Washington, D.C.: Federal Highway Administration, retrieved 25 Jun 2019

   1 more example

   Four-axle trucks with a conventional 9-ft overall spacing for the tridem axle would have a maximum GVW of 64,000 lb (limited by 44,000 lb on the tridem).

   1990, Truck Weight Limits: Issues and Options, Washington, D.C.: Transportation Research Board, page 187

   Synonyms: triple