An automated storage and retrieval system includes a track system having a first set of parallel tracks and a second set of parallel tracks. The first and second sets of tracks form a grid pattern of grid cells. Storage containers are arranged in storage columns located beneath the track system. Container handling vehicles lift and move storage containers. The container handling vehicles are configured to move laterally on the track system above the storage columns to access the storage containers via grid openings. Each container handling vehicle includes: a protruding section which extends horizontally beyond the footprint of the container handling vehicle and, when the container handling vehicle is positioned above a grid cell, into a neighbouring grid cell; and a recessed section arranged to accommodate the protruding sections of another container handling vehicle when operating over a neighbouring grid cell.