The 37 kilometre route runs through Ninh Hoa town and Van Tho commune in Van Ninh district and includes 18 bridges.
The segments through rural areas will be 20.5 metres wide with a maximum speed limit of 80 km per hour, while those in urban areas will be 25.5 metres wide and have a speed limit of 60 km per hour.
This expansion is one of the major works in the project to extend National Highway 1A from Hanoi to Can Tho and is scheduled to be completed in 30 months.
On the same day, construction of the 500m long Co Ma tunnel in Van Ninh district, Khanh Hoa province, also began as part of the National Highway 1A Ca Pass tunnel project to connect Phu Yen and Khanh Hoa provinces.
Construction of the tunnel is expected to take two years and cost nearly VND1 trillion (US$48 million).
