When we think of bridges, it is the dramatic and monumental long spans that come to mind first, especially the lithe suspension bridges such as the Golden Gate and the pure geometric arches such as Sydney Harbour. But the majority of bridges are not such spectacular structures. Most of them are ordinary overpasses, with spans of 30 or 40 feet, carrying roadways or rails across other thoroughfares or over small streams. You see such bridges by the dozen on any drive down the Interstate. They may be lacking in glamour, but they are more representative of a bridge builder's art.
The engineering and construction of girder bridges are pretty routine these days, but the bridges are not quite standard items you order from a catalogue. The girders, whether of steel or concrete, are custom-build for each bridge, then trucked to the site and hoisted into place with a crane. The designer still has scope for variation and creativity, and it shows out on the highways: some overpasses are prettier than others.
There are deep moral/practical reasons for our search which give form to our work: with the form we create we can adjust to the laws of matter with all reverence, forming a dialogue with reality and its mysteries in essential communion... For architecture to be truly constructed, the materials must be used with profound respect for their essence and possibilities; only thus can 'cosmic economy' be achieved... in agreement with the profound order of the world; only then can have that authority that so astounds us in the great works of the past.