SHANGHAI’S road construction authority is to employ innovative “water knife” technology to repair elevated highways, bridges and tunnels across the city from next year to help cut down on noise and dirt.

Water jet cutting machinery will replace traditional pile-driving machines to dig holes and remove the old surface of roads, tunnels and bridges undergoing repairs, the Shanghai Urban Construction Group said yesterday.

Using the water knife will cut the noise from more than 100 decibels to around 70, while also avoiding clouds of dust and acrid smoke, said Pan Wei, general manager of the project management department with the group.