Oregon Bridges Unsafe from Earthquakes

The outlook is not good for Oregon bridges in a major earthquake.

A study released Monday concludes that U.S. Highway 101 on the coast would be impassable, all connections from the coast to the Willamette Valley would be broken, and only small parts of Interstate 5 would be passable.

The assessment is based on a major Cascadia subduction zone earthquake off the Oregon Coast, which geologists estimate has a 10 to 14 percent chance of happening in the next 50 years.

ODOT spokesman Dave Thompson says it would cost $3 billion to bring all those bridges up to modern seismic standards, and the value of the study is to identify which bridges should be upgraded first to keep crucial highways open in event of a big quake.