This paper analyses the influence of horizontal bracing restraints provided by the friction between pallet bases
and rail beams on the static behaviour and design of steel drive-in storage racks. The pallet bracing restraints
are shown to significantly influence the structural behaviour of the rack, and their effect on the bending moment
distribution of the uprights is studied in the paper. The 2D single upright model proposed by Godley is improved
in this study by including the restraints provided by the plan flexural stiffness of the rail beams and the friction
between the pallets and rail beams. The improved 2D model was found to accurately reproduce the bending
moment distributions obtained using 3D advanced finite element analysis. The 2D single upright model is used
to analyse 36 drive-in racks under various load case combinations. The paper evaluates the influence of the pallet
bracing restraints on the ultimate capacity of drive-in racks, clarifies the loading pattern(s) governing the
structural design and determines the friction coefficient, or strength of a restraining device, required to prevent
the pallets from sliding. It is shown that while restraints from pallets could potentially be considered in design,
they would not lead to more economic structural solutions.