Millennium Bridge, London people walking caused small sideways oscillations in the bridge, which in turn caused people on the bridge to sway in step, increasing the amplitude of the bridge oscillations and continually reinforcing the effect. On the day of opening, the bridge was crossed by 90,000 people, with up to 2,000 on the bridge at any one time. Resonant vibrational modes due to vertical loads (such as trains, traffic, pedestrians) and wind loads are well understood in bridge design. In the case of the Millennium Bridge, because the lateral motion caused the pedestrians loading the bridge to directly participate with the bridge,
London Bridge Greater London Authority. The crossing also delineates an area along the southern bank of the River Thames, between London Bridge and Tower Bridge, that has been designated as a business improvement district. The abutments of modern London Bridge rest several metres above natural embankments of gravel, sand and clay. From the late Neolithic era the southern embankment formed a natural causeway above the surrounding swamp and marsh of the river's estuary; the northern ascended to higher ground at the present site of Cornhill. Between the embankments, the River Thames could have been crossed by ford when the tide was low,