This recommended practice shall apply to all on-highway trucks and truck-tractors equipped with air brake systems and having a GVW rating of 26 000 lb or more.
Previous versions of this Recommended Practice provided guidance on the locations of instruments and controls in truck cabs. This guidance assumed that the cab design employed a flat dash panel and standard switches. With the advent of wrap-around style operator environments, display screens, GPS, etc., this guidance no longer applies. However, the need for consistent location and identification of the air brake controls is still pertinent and beneficial. This document has been revised accordingly. Truck designers interested in guidance concerning the location of cab controls other that the air brake valves can reference TMC RP401.