Both of Canada’s major freight railroads have come to a full stop because of a contract dispute with their workers, an impasse that could bring significant economic harm to businesses and consumers in Canada and the U.S. if the trains don’t resume running soon. Canadian National and CPKC railroads both locked out their employees after the deadline of 12:01 a.m. Eastern Thursday passed without new agreements with the Teamsters Canada Rail Conference that represents some 10,000 engineers, conductors and dispatchers. ... All rail traffic in Canada and all shipments crossing the U.S. border have stopped... Billions of dollars of goods...