Congestion at US ports together with shortages of rail and road capacity are causing delays to containers and threatening import-export growth, China's Cosco group has warned. The executive vicepresident of Cosco told the Propeller Club that Americans needed to pay attention to the problem. He explained that not all ports have the terminal efficiency, water depth or bridge clearances to accommodate the bigger ships, and called for greater flexibility in rules governing interview requirements for ships' crew visas.