Trucking companies and freight rail operators are scrambling to move billions in trade that has been arriving at the 14 ports where the largest longshoremen's union in North America is planning to strike after midnight Monday if a new contract is not reached with ports management.

U.S. ports from Maine to Texas could shut down Tuesday if a union representing about 45,000 dockworkers carries through with a threatened strike. A lengthy shutdown could raise prices on goods around the country and potentially cause shortages and price increases at big and small retailers alike as the holiday shopping season — along with a tight presidential election —