Storage and retrieval system

A storage array in an automated storage and retrieval system includes storage spaces arrayed on racks along picking aisles, multiple level decks, where at least one deck communicates with each aisle, where the decks and aisles are configured to define a rolling surface for an autonomous transport vehicle at each level of the decks, racks along at least one aisle at each level are at multiple rack levels that are accessed from a respective rolling surface that is common to the multiple rack levels, and a vertical pitch between rack levels varies for a portion of a respective aisle, the vertical pitch between at least two rack levels of the portion of the respective aisle is related to another vertical pitch between at least two other rack levels of another aisle portion of the respective aisle so the vehicle effects multiple picks in ordered sequence in a common aisle pass.