China’s week-long National Day holiday has exacerbated congestion at two of the country’s busiest ports — Shanghai and Ningbo — where 273 cargo and container vessels were waiting to berth as of Thursday. 

Container rollover rates at both ports indicate little headway in dealing with the excess cargo, according to data from supply chain software company project44. The backlogs spell further product shortages and delays for businesses and consumers as holiday shopping picks up. 

Rollover rates, defined as the percentage of containers that miss their scheduled sailings, rose to 36% in September at the Port of Ningbo — which was temporarily shut when a worker tested positive for COVID-19 in July. The ports of Hong Kong and Shanghai showed slight reductions in rollover rates, yet remained high at 41% and 37%.

Containerized trade through Chinese ports accounts for 40% of global container trade, and Shanghai and Ningbo are currently the world’s busiest and 3rd busiest container ports. 

China’s “Golden Week” from Oct. 1 to 7 is one of two lengthy holidays in a country where workers have few personal vacation days.