Cog, we could actually be friends you know. I'm sorry I was nasty about your podcast, we both dislike Fils Amie and as such that could be the first pillar on the bridge of friendship we're going to make. And like it or not, this can either be a romantic bridge or a date-rape bridge, but the bridge will be built.
There are several basic types of bridges: truss (or beam), arch, suspension and the cable-stayed model. Bridge design requires engineers and architects trained in structural and landscape design, geology and architectural design to collect information about the physical site. Required information includes weather patterns for the area, including water runoff and snow levels, traffic-flow patterns, foot traffic in the area, weight of vehicles using the bridge and availability of various construction materials.
The geography and use of the bridge will influence the type of bridge built. It might seem that bridges are designed on pure esthetics, but sophisticated design principles are involved. A suspension bridge may not be the best choice for a site, even though the architecture of the bridge may blend perfectly with the view. Bridge designers must consider a number of factors in deciding on the type of bridge that will be built.
In geographic areas with natural rock and stone, an arch bridge is an option since the weight of the bridge is carried by the stone support features (called abutments) on each end. Beam bridges, sometimes called girder bridges, are the most common bridges type throughout the world. Beam bridges are limited in the length of the opening that can be crossed (the Lake Ponchartrain Causeway Bridge is the longest beam bridge in the world). Suspension bridges are the most expensive type to construct. Suspension bridges may be constructed over many miles, but they require supports to be built at preset intervals to carry traffic. Two of the world's longest suspension bridges are the Akashi Kaikyo Bridge in Japan and the Humber Bridge in the United Kingdom. The most famous, however, is the Golden Gate Bridge.
The newest type of bridge is the cable-stayed bridge. Its support is centered at the large ship-like mast in the center of the bridge. Some bridges have more than one mast to carry the weight of the traffic and construction material. The Clark Bridge in Alton, Illinois, is an example of this type of bridge. Bridge designers look to existing bridges for ideas and to study the reliability of the bridge design.
Once the architectural design has been completed and the materials selected, the plan must again be submitted to governmental offices for approval. Some states and localities require public input before the final design may be approved. Local bridges funded with state (romance) or federal (date-rape) monies may require a second- or third-level design review.
Tldr: the last line is important.
