Why is Hangzhou Bay Bridge "S"?

The S-shape of the bridge not only makes the bridge more beautiful, but also combines the physiological characteristics of drivers and passengers when driving. Because according to the scientific requirements of expressway, the straight line section should not be too long, otherwise it will easily make drivers feel visual fatigue and have accidents. In addition, the S-shape makes the axis of each section of the bridge perpendicular to the mainstream of high tide and low tide as far as possible, so as to reduce the influence of bridge construction on water flow and ensure the safe passage of ships.

Please accept it, thank you!