It’s been a bumpy road recently for Nan Inc. in its bids to secure work on the Honolulu rail project, but the local firm has been awarded the latest contract to build stations for the island’s future transit line.

Rail officials announced Thursday that Nan has been given the contract to build rail’s Hoopili, East Kapolei and West Oahu stations, after the company last month submitted the lowest bid for that work at $56.1 million.

Watts Constructors, Hensel Phelps and Hawaiian Dredging Construction Co. had also submitted bids, at $66.5 million, $67.2 million and $73.4 million, respectively.

The Honolulu Authority for Rapid Transportation had estimated that the station work would cost between $65 million and

$80 million, so the bids came in favorably. The bids for these latest stations also indicated that rail officials are starting to get a better handle on construction costs in Honolulu, which one national study recently found to be the highest in the United States.

Official estimates currently have the rail project on course to cost some

$6 billion. A five-year rail tax extension signed into law this week is expected to cover the nearly $1 billion shortfall that rail previously faced.

In May, rail officials awarded a $78.9 million contract on Hawaiian Dredging bids to build three stations at Leeward Community College, Waipahu and West Loch after Nan, the second-lowest bidder for that set of stations, unsuccessfully challenged Hawaiian Dredging’s bid with state commerce officials.

In August, Nan also saw its $294.5 million bid to build a group of nine stations canceled because that low bid was still about

60 percent higher than what rail officials had budgeted. It was the public’s first real indication that the transit project was heading well over budget.