Monthly schedule reliability of major container liners by carrier 2020-2024

Schedule reliability of major container carriers oscillated between November 2020 and October 2024. In May 2023, about 73.5 percent of the ships operated by Maersk—who topped the list as the most reliable container carrier this month—arrived at their destination on time. This represents a significant improvement in schedule reliability compared to 2021 and 2022. Unfortunately due to various disruptions in trade routs, such as the Red Sea crisis, schedule reliability fell dramatically in 2024, where Maersk showed 57.9 percent reliability.

Reasons for ship delays

Throughout 2021 and 2022, some of the largest ports in the world were struggling with labor shortages, mandatory port closures due to coronavirus outbreaks, and late arrivals of vessels. These have either restricted port operations or stopped them altogether. Some ships could skip the affected port and continue on their route to the next port, but most ships had no choice but to wait at the port until its operations resumed. This has led to an accumulation of vessels at ports, causing port congestions and, in turn, more ship delays.

Port congestions in the U.S. and China

In October 2021, 53 ships were waiting outside Los Angeles and Long Beach ports, up from just five vessels in October 2020. From April to May 2022, between 29 and 46 ships were waiting at these ports.
Due to China’s strict zero-COVID policy, some of the busiest Chinese ports have been put on lockdown in the past two years to curb the spread of the virus. In March and April 2022, about 470 and 506 ships were waiting outside Chinese ports, respectively.