The Sagamore Bridge and Bourne Bridge, which cross the Cape Cod Canal, are both due to be replaced at a combined estimated cost of $4.5 billion.

Maintenance and repair work is planned for two spans linked to mainland Massachusetts while designs for their estimated $4-billion replacements move forward.

Three tidal turbine energy developers, including one U.K. company, are planning to test their prototypes at the world’s first-of-its-kind permanent tidal test site on the Cape Cod Canal in Massachusetts.