What is the recommended minimum size for a gangway (not the operating aisle) or transfer aisle for a typically sized standard reach truck?

It is not possible for the FLTA to advise on gangway width as there are so many factors to take into account.

The dimension of the widest part of any truck, or its load, likely to use the gangway would be the starting point.  For a conventional Reach Truck, our recommendation would be to allow a minimum of 50mm clearance of the widest point of the truck, on each side, and this may need to be increased, to improve visibility and or productivity, depending upon the overall length of the gangway.