The landmark Kopu Bridge near Thames is set to be demolished, but a group fighting to save it will continue their efforts.
The 85-year-old bridge has not been used since a new one was opened in December 2011.
The Historic Kopu Bridge Society wanted ownership transferred to it so the structure could be re-opened for recreational use.
But the Transport Agency says the proposal is not viable and the bridge will have to be demolished. The society's interim chairman, Gary Blake, says it plans to challenge the decision.
The Transport Agency says a demolition date is yet to be set.