When a new highway loop was being completed in West Michigan, a real danger was discovered. The bridges had been designed to bear their own weight—but not the traffic they were intended to carry. Before the highway could be opened, several bridges had to be re-engineered and rebuilt.
Engineers have to be especially concerned with the tensile strength of the material in their construction plans for structures that are required to bear large amounts of stress due to weight. Tensile strength is the maximum amount of stretching a material can withstand before it tears. If the engineer miscalculates, the structure may collapse under the pressure.