Judy's Cards

The design of the Mackinac Bridge was directly influenced by the catastrophic failure of the first Tacoma Narrows Bridge in 1940 due to instability in high winds. Three years after that disaster, Steinman had published a theoretical analysis of suspension bridge stability problems which recommended that future bridge designs include deep stiffening trusses to support the bridge deck and an open-grid roadway to reduce its wind resistance. Both of these features were incorporated into the Mackinac Bridge. (from Wikipedia)