The collapse of the I-35W Bridge in Minneapolis was a national tragedy that demonstrated the significant public safety threat that exists if repairs to our nation’s bridge infrastructure are delayed. While loss of life and personal injury were certainly the most significant outcomes, the enormous economic impact of such an event must be noted as well. The total economic impact could exceed $600 million, or four-times the bridge replacement cost.

Since 1990, the I-35W Bridge was rated structurally deficient. According to the U.S. Department of Transportation, of the 597,340 bridges in this country, 154,101 bridges are deficient, including 73,784 that are structurally deficient and 80,317 that are functionally obsolete. It is estimated that more than $65 billion is needed to address this problem.

Given the other significant infrastructure needs in this country, it is not expected that this level of funding will be available over the short term, even though it is hoped that Congress will increase the level of bridge funding in the next transportation bill. That said, we also understand that blindly throwing money at the problem is not the answer.

So how do we make sure that the funding, however much it is, gets spent strategically and toward improving bridge safety? Here’s how: It’s time that the federal government adopt a risk-based prioritization approach to bridge safety, similar to what is used in most other fields where human safety can be jeopardized, and the economy can be injured. This approach would establish funding priorities and ensure that funding is targeted at those bridges posing the highest safety risks, and the greatest economic consequences from a failure.

Risk-based prioritization would rank the nation’s bridges according to factors such as age, loading, design, and structural and functional condition, among others. A threshold risk index would be established and those bridges with a risk index above the threshold would be eligible for prioritized funding based on consequence of failure.

This methodology would also be used to improve our national bridge inspection program, which is another critical link in ensuring bridge safety. This would allow states to target inspection methodology such as inspection intervals, inspection team qualifications, and level of inspection according to risk. The time is now to adopt a risk-based approach to ensuring the safety of our nation’s aging bridge infrastructure.

Ray McCabe, P.E., is the national director of bridges and tunnels, HNTB Corporation.