The role of expansion joints is to provide smooth and safe transition of road traffic over the expansion gap in the bridge structure. They provide watertight protection of the gap and enable the possibility of movements which are induced by the changes of temperature as well as due to the traffic loads. The role of expansion joints is to provide smooth and safe transition of road traffic over the expansion gap in the bridge structure. They provide watertight protection of the gap and enable the possibility of movements which are induced by the changes of temperature as well as due to the traffic loads.