While the hub-and-spoke function accounts for about 85% of all transshipment activities, intersection and relay functions account for about 15%. Transshipment was initially developed to service smaller ports that had poor nautical accessibility (sites unable to accommodate larger containerships) or limited infrastructure, which lead to the setting of hub-and-spoke networks. At a later stage, intersection and relay forms of transshipment were introduced, enabling different levels of connectivity within global maritime shipping networks.