Abstract
This paper summarizes a comprehensive research program efthe rde qualities of lonb-haal trucks: Factors are iden-tified ivhich contribute significanty to differences inride quality botereen various truck roodels and configura-tions over a range of actual operating cenditions. petai-led measurements of sx floor and seat acceleraticns anddriver and passenger rde ratings erere made on ten in-ser-vice trucks over five segments, rangmg from "smooth" to"rough" of a typical California freeway.