Commentary

I-5 Bridge Collapses; Washington State Ranked 34th In Making Progress on Deficient and Functionally Obsolete Bridges

The Seattle Times reports:

An Interstate 5 bridge collapsed into the Skagit River on Thursday evening, according to the Washington State Patrol. Trooper Mark Francis wrote on Twitter that people and cars are in the water. Both the north bound and south bound lanes were in the water, Francis wrote.

Our Reason Foundation study, “Examining 20 Years of U.S. Highway and Bridge Performance Trends,” found Washington ranked 34th out of 50 states in terms of making progress reducing its percentage of deficient and functionally obsolete bridges from 1989 to 2008. Overall the findings on functionally obsolete and deficient bridges were:

Federal law mandates the uniform inspection of all bridges for structural and functional adequacy at least every two years. Bridges are rated “deficient” if they are deemed either “functionally obsolescent,” for instance being too narrow for current traffic, or “structurally deficient” in condition. About one-half of deficient bridges are in each group. Funds are allocated to states based on estimated costs to repair deficient bridges.

The nation has made considerable progress in reducing the backlog of deficient bridges over the past two decades. The percentage of bridges rated deficient nationwide has been reduced by about 14 percentage points, from 37.8% to 23.7%. However, the rate of reduction seems to be slowing, since in the last 10 years, the percentage of deficient bridges has been reduced by about 4.5 percentage points, or about 0.45 percentage points per year. At this rate, it would take about 52 years to exhaust the backlog of deficient bridges nationwide. Further, since most of that money is spent on structurally deficient bridges, the percentage of functionally obsolescent bridges has not reduced as much.

The progress in meeting bridge deficiencies has been quite widespread. Of the 50 states, 40 registered improvement in the percentage of deficient bridges over 20 years. They are led by Mississippi and Nebraska, reporting an improvement of 31.7 and 31.5 percentage points, respectively. Nine states, led by Colorado, cut their percentage of deficient bridges by half or better.

On the other hand, 10 widely scattered states reported a worsening percentage of deficient bridges. They are led by Hawaii and Alaska at 14.3 and 10.5 percentage point increases, respectively. Arizona reported the highest relative increase, a more than doubling of its percentage of deficient bridges, but from a very low 1989 base of just 5.4%.

Full report here (.pdf).

David T. Hartgen

David T. Hartgen is Emeritus Professor of Transportation Studies at UNC Charlotte. Professor Hartgen is widely known in transportation circles. He established UNC Charlotte's Center for Interdisciplinary Transportation Studies in 1989 and now teaches and conducts research in transportation policy and planning. He is the author of about 330 studies on a wide variety of topics in transportation policy and planning, is the U.S. editor of the international academic journal Transportation, and is active in professional organizations. He is a frequent media interviewee in local and national outlets. Before coming to Charlotte he directed the statistics, traffic forecasting and analysis functions of the New York State Department of Transportation and served as a Policy Analyst at the Federal Highway Administration. He holds engineering degrees from Duke University and Northwestern University. He has taught at SUNY Albany, Union College and Syracuse University and lectures widely. His studies of the comparative performance of transportation systems have received nation-wide attention. He has also recently completed a major component of Reason's Mobility Study that estimates the cost of significantly reducing road congestion nation-wide, a comprehensive study of congestion in North Carolina, and a comparative study of the 50 state highway systems . His current research includes an assessment of the economic impact of highways in South Carolina, a review of transportation performance for the provinces of Canada, a national study of business impacts of congestion, and an assessment of congestion in mid-sized cities.