This is one of the very first question I have when doing the 1st project.

Typically, you will notice the pallet racking rows are in the same direction as the loading bays as the 1st picture below.

The reason is because the putaway team is able to get the pallets from the staging area to storage locations directly. Likewise, the picking team is able to bring the pallets from the storage locations to the staging area straight away.

If the pallet racks rows are placed horizontally across, in order to reach the pallet bay in the middle, the forklift driver needs to go in from one end and come out from the other.

The travelling distance is much longer.

However, the above is just a rule of thumb. There are other reasons that should be factored in as well, which may lead to the setting up of the rows as the 2nd alternative.

This is good. Learnt something new.
No wonder for the warehouses I have been to, the pallet racks are in line with the loading bays.

An appropriate approach to fully load a pallet rack is to start at the bottom middle of the rack row and to work outwards and upwards.