Work on the La Son-Tuy Loan expressway, crossing Bach Ma National Park, a top trekking destination, is now 99 percent complete, a management board representative said.

However, the project is still awaiting approval from the State Council for Pre-acceptance Test of Construction Works before it could open to traffic.

It was previously scheduled to enter operation last year but was delayed as some sections of the expressway were eroded due to the impacts of historic flooding in central Vietnam.

The 77.5-kilometer expressway cost nearly VND11.5 trillion ($495 million) and was built to ease traffic congestion along the existing National Highway 1 and foster economic development in the central region.

Construction on the project began in 2015 but was delayed several times due to land acquisition problems and unfavorable weather.

It runs between the La Son intersection of Loc Son Commune, Huong Thuy District of Thua Thien-Hue and Tuy Loan Village of Da Nang’s Hoa Vang District.

Over 11 kilometer of the expressway traverses Bach Ma national park, a popular destination in Thua Thien-Hue Province, home to tourist hub Hue. The park spreads over more than 37,000 hectares and rises 1,450 meters above sea level at its highest point. Rich in biodiversity, the park attracts trekkers with its lush forests, waterfalls and lakes.