A problem with pedestrian bridges is that people walking in step can create large vibrations and even resonance that can damage the bridge. This problem is sometimes solved by people walking out-of-step with each other as they cross the bridge. However, in this case, the vibrations were so bad that the bridge was closed until special devices could 'dampen' the bridge's response.
The Millennium Bridge is an unusual three span suspension bridge with the cables hanging below the deck to give pedestrians an unobstructed view of their surroundings. The spans are 81 meters, 144 meters, and 108 meters for a total length of about 333 meters. The deck is 4 meters wide and can carry about 8000 pedestrians. The designer was Ove Arup who made a name for himself designing innovative, pedestrian bridges.
Suspension Bridges: The Millenium Bridge by Mark Yashinsky is licensed under a Creative Commons Attribution 3.0 United States License.