In following the Columbia River Crossing issue, I became aware of the latest generation of metal arch bridges. Engineers have discovered that diagonal cabling makes any bridge stronger (think cable-stayed design) as opposed to vertical suspension cables — the downfall of the original Tacoma Narrows Bridge. Network Tied Arch bridges use diagonal cabling, plus other features that double up engineering functions. They are seismically safe, affordable, and elegant. A 7-mile-long I-74 improvement in the Midwest will use a pair; project cost: $1.5 billion. Kentucky built two Network Tied Arch bridges in the Lakes area for $450 million.
We should have a west route connecting Vancouver to U.S. Highway 26 — and an east bridge connecting state Highway 14 to Troutdale, Ore., for a sum comparable to an I-5 Bridge replacement. And greatly improved traffic relief.