New York state officials say the new Tappan Zee Bridge project is on budget and on schedule.

The Journal News reports that the Thruway Authority says the $3.9 billion, 3-mile-long bridge is expected to be finished by mid-2018.

Crews have finished installing steel beams on its south span that will support the road deck.

Officials say some cable stays that will support the decks of the twin spans have been strung between the two 419-foot towers and the roadways. That work is ongoing.

The remaining steel girders that support the deck are expected to be installed in the coming weeks. About a third of the deck panels have also been installed.

Contractors tasked with designing and building the bridge say demolition of the old bridge is expected to begin in 2017 or 2018.

(AP)