3.1.2. Flow around the bridgeFor the truss bridge, seen in Figure 11(a), a pressure distribution similar to that of the train can be observed: ahigh-pressure zone mainly appears on the windward sideand a lower pressure zone on the other sides. The aerodynamic effect of moving train is presented in terms ofthe distinct suction area where the pressure decreasesalong the traveling direction of the train, reported inFigure 11(b). It is worth noting that the location of train isconstantly changing, so the pressure distribution on thedeck of bridge also varies with the time, which can leadto the time-varying aerodynamic forces on the bridge.