Analysis of global liner network data since 2012 reveals a fundamental shift in how shipping lines manage their networks. Although shipping lines have largely maintained their geographical footprint, liner service frequencies have contracted significantly since the disruptions of 2020.
Tracking the relationship between Network Reach (unique direct deep‑sea port‑pair connections) and Network Density (total volume of calls executed across those connections) demonstrates a historical correlation that fractured in early 2020 and has not yet re‑coupled. From 2012 to mid‑2018, both metrics grew in tandem as shipping lines expanded their networks. In January 2012, the global deep-sea network consisted of 6,553 distinct port‑pairs serviced by 42,129 monthly calls, peaking in 2018 at 12,056 distinct connections and 81,926 monthly calls. During this phase, new port‑pair additions were matched by frequency injections. This operational strategy has since transitioned. When the structural decoupling accelerated throughout 2020, Network Reach experienced only a moderate rationalization, dropping to a baseline of approximately 10,500 connections by the end of 2021. Network Density, however, contracted disproportionately. (....)