The expressway runs 40.3 kilometres from Phu Luong district in Thai Nguyen province to Cho Moi district in Bac Kan province.
The same day, construction also started on a project to upgrade 25 kilometres of the National Highway 3 section connecting Son Cam and Yen Do communes of Phu Luong district.
The two projects are estimated to cost a total of VDN2.75 trillion (US$129 million).
The Thai Nguyen – Bac Kan Expressway is expected to help reduce traffic on National Highway 3 and is a significant part of the freeway system linking the capital Hanoi with provinces in the northern mountainous region.
Speaking at the ground-breaking ceremony, PM Dung praised the Ministry of Transport (MOT), authorities in Bac Kan and Thai provinces and relevant agencies for their thorough preparations for the start of this important artery.
He urged road constructors to fulfil their pledge to complete and put the expressway into use after 18 months, with the best quality possible.
The prime minister also asked local authorities to help remove obstacles during construction so that the project can be completed on schedule, as well as ensuring benefits for people displaced by the project.
On this occasion, PM Dung requested MOT and concerned provinces to conduct research and prepare for the expressway from Bac Kan through Cao Bang to Lang Son.
