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 station provided at London Bridge; the first station south of the river was at Borough. King William Street was found to be badly placed owing to a steep incline towards the station from underneath the Thames, which limited its capacity. When the decision was made to extend the C&SLR northwards to Moorgate, a new pair of tunnels was constructed from north of Borough station on a new alignment providing a more convenient route and the opportunity to open a station at London Bridge. The tunnels to King William Street and the station were closed and the extension and London Bridge station