The Wando River bridge also had modular joints, some of which began to fail soon after the bridge opened. Engineers found defects in those joints, however. Lawsuits were filed, and construction crews replaced the modular joints with finger joints as part of the settlement. Safety was one reason. A finger joint is a relatively large chunk of steel, and a metal road surface can be slippery, especially in the rain.
Modular joints use less metal, making for a more sure-footed driving surface.
Tony Bartelme covers maritime and other issues.