A memory allocation scheme for list structures (ral system) is proposed, which allows random access and search for the elements of the structure. A comparative study of classical list systems and ral systems is given, for the basic operations of search, insertion, deletion and sorting of the structure elements. It is shown that, in general, ral systems exhibit lower order expected time complexities for such operations, possibly at the expense of a reasonable increase in memory occupation. Allocation and processing of linear ordered lists and trees are discussed in particular.