Metroblogging Portland pointed out an article in today’s Oregonian about the constraints a new bridge design will face when it comes to elevation and appearance:
Vertical constraints for a new Columbia span could mean a simple, flat design
Some of the region’s political leaders have said yes. They want a new Interstate 5 span not only to cross the Columbia River, connecting Portland and Vancouver, but also to be worthy of a postcard, showcasing a world-famous river at the border of two states bent on sustainability. Perhaps it could soar like Portland’s Fremont Bridge or even San Francisco’s Golden Gate.
But under the first round of plans, the new bridge will be a flat concrete slab.
The article goes into detail about the reasons why the bridge must be constrained to a narrow 75′ band of airspace. But one thing not given significant mention is an issue of cost: Would removal of those constraints result in a less expensive structure? Would alternative span designs with more visual impact cost more or less than current plans?
Of course, no matter what kind of bridge they build, it couldn’t possibly be as plain and ordinary as the transition along I-5 between Oregon and California. :-)