Underpasses and overpasses separate conflicting traffic flows onto different levels, increasing junction capacity and markedly reducing accident risk. On state highways passing through settlements they are also decisive for pedestrian safety.
Construction is staged on the principle that existing traffic keeps moving. Temporary traffic management schemes are prepared, and site safety and signing systems are installed. Shoring and water discharge are the critical items in underpasses; girder erection and deck construction in overpasses.
