An attempt is made through the Paper to introduce, as a basis for discussion, design standards for composite structural steel and reinforced concrete decks for. modem highway bridges. The Paper describes the design standards developed by the Authors in the absence of any current code to cover the increasing number of composite structures now being erected in Southern Rhodesia. The Authors have drawn heavily on previously published technical information from both British and American sources, and have endeavoured to compile an ad hoc code to suit the prevailing conditions in the Federation. Little opportunity has been available for experimental work to verify several unsolved problems. The question of the dynamic stability of decks subject to a relatively high live-load/dead-load ratio, the possibility of incorporating prestressed precast concrete units in the composite compression zone, the prestressinogf steel during construction, and the effective slab width and transverse distribution usingo pen frames, are subjects which the Authors would like to devote considerable time to in the experimental and research laboratory, particularly in the sphere of continuity.