In Rhode Island a decade ago, a new interstate bridge was fabricated at a shoreside facility about fifteen miles away, whilst the new abutments were being prepared. The completed bridge fabrication was then loaded on a barge, moved into place at high tide, then as the tide receded the bridge eased into the new abutments.
Brilliant cost saving engineering!
They just used that method to replace part of the Sarah Mildred Long Bridge (U.S. 1) between Maine and New Hampshire.