The intersections at either ends of the bridge, built in 2001, were in close proximity with nearby residential areas (as close as a meter), the department said. With traffic density on the bridge reaching as much as 100,000 vehicles per day, the noise has severely affected the lives of citizens in the area, it added.

Noise surveys at 19 locations near the bridge’s two ends showed that the decibel levels exceeded national standards. The department did not mention specific figures.

The national noise limits in residential areas are 70dBA from 6 a.m. to 9 p.m., and 55dBA from 9 p.m. to 6 a.m.

The installation of the plates, which would cost VND15 billion ($646,518), should be finished before the Lunar New Year Festival in late January, it added.

Connecting Hoan Kiem District and Long Bien District, the four-lane 1.23km long Chuong Duong Bridge was the first bridge designed and built in the country without technical assistance from foreign experts. It was built from 1983 to 1986.

The bridge was initially designed to handle an estimated 7,000 vehicles a day, but that number quickly increased.