A system including one or more processors and one or more non-transitory computer-readable media storing computing instructions that, when executed on the one or more processors, perform certain acts. The acts can include obtaining information about a trailer that has been partially loaded with preloaded stacks in a manner that deviates from an original load design. The trailer is being loaded with stacks of pallets comprising the preloaded stacks and unloaded stacks. The acts also can include determining positions of empty floor spots remaining in the trailer. The acts additionally can include determining a first portion of an incremental load design for the unloaded stacks using a gap-filling pattern behind an uneven rear edge of the preloaded stacks. The acts further can include determining a second portion of the incremental load design. The acts additionally can include updating the incremental load design based on an overall load design of the trailer. The acts further can include outputting at least the incremental load design, as updated. The incremental load design can specify a respective floor spot assignment for each of the unloaded stacks. Other embodiments are described.