White Paper #2



A Better Way to Fix Our National Bridge Problem


A White Paper by LifeSpan Technologies

October 2008




It’s been more than a year since the I-35W bridge collapse.  Fortunately, the new I-35W span opened ahead of schedule and life is getting back to normal in Minneapolis.  Meanwhile, public concern and the headlines have shifted from our structurally deficient bridge problem to subprime mortgages and collateralized debt obligations (CDOs).  Does that mean the bridge problem has gone away?  Hardly!  The financial collapse just made the bridge problem worse.  The principal bridge owners; states, counties and cities will now have to scrape for every dime just to meet their existing obligations (1), much less replace thousands of structurally deficient bridges.

Isn’t Washington coming to the rescue?

The federal debt is now over $10 trillion dollars, nearly equaling our gross domestic product (GDP).  Our Treasury Department and Federal Reserve recently added to this obligation by promising to bail out holders of toxic CDOs related to the subprime mortgage crisis.  In addition, the nationalization of Fannie Mae, Freddie Mac and AIG; and the $250 billion capital infusion into the U.S. banking industry foretell questionable future funding for transportation (2).

In this white paper, LifeSpan recommends how Congress, the next Administration, and citizen taxpayers can most efficiently resolve our bridge problem without simply hurling unnecessary mountains of money our grandchildren will ultimately have to repay.



Historical Context


In 1967, the Silver Bridge collapse over the Ohio River resulted in a programmatic response from Congress and the Federal Highway Administration (FHWA) to institute a biennial bridge inspection program called the National Bridge Inspection Standards, or NBIS  (3).  Inspectors were hired by State Departments of Transportation (DOTs), training courses were implemented, and the inspection process began in earnest.

For over thirty five years, bridge inspectors have used their eyes, flashlights, ball-peen hammers, wire brushes, rulers, cameras and clipboards to assess the condition of every U.S. bridge over twenty feet long.  Bridge inspectors have done a reasonably good job, given their level of training and tools.  However, the NBIS process has resulted in over 70,000 bridges being classified as structurally deficient.  In addition, many more U.S. bridges are reaching the end of their design life, are being crossed daily by overweight vehicles, and have not received adequate maintenance in a long time.

Over the past several years, thought leaders in the transportation industry have been questioning the efficacy of visual inspection using the NBIS protocols.  In a landmark study published in Public Roads Magazine: “Reliability of Visual Bridge Inspection”  (4), the FHWA concluded that visual inspection is subjective, highly variable, and not sufficiently reliable. It’s understandable that a visual inspection process can’t provide precision, so let’s not blame the inspectors.  They’re doing the best they can, given the tools they have.

However, there are fully commercialized advanced technologies that bring much needed precision and objectivity to the inspection and evaluation process.  Further, advanced computer modeling adds another dimension to bridge evaluation that was not available even five years ago – technology to the rescue  (5).

Given historically generous transportation funding, the inherent conservatism of visual inspection and analytics wasn’t considered a problem.  For example, no one was particularly concerned about replacing a bridge ten years earlier than necessary.  However, today’s financial crisis has changed the old paradigms.

States, counties and cities, the owners of nearly all this nation’s bridges, have enormous funding challenges that will not allow wholesale replacement of all structurally deficient bridges.  And with diminished ability to raise debt capital, the financial crisis makes this task that much more difficult.

We believe bridge owners, despite having to pay only 20% of bridge replacement costs (Washington DC pays the other 80%); will still have difficulty in mustering the necessary funding.  The unfortunate financial cratering of Missouri DOT’s innovative Safe & Sound Program to rehabilitate or replace 803 bridges is a recent example.  And we believe this funding condition will last for decades – it is not a temporary phenomenon.

So bridge owners need to obtain the maximum safe life span on every bridge, simply to avoid having to fund the capital cost for replacement.



Federal Funding Outlook


This summer, the Highway Trust Fund (HTF) ran out of money  (6).  This fund, used as the primary means to support highway construction projects, was granted an $8 billion dollar lifeline by Congress, just to keep ongoing projects moving forward.  The National Surface Transportation Policy and Revenue Commission reported in January 2008 (7) that future transportation funding would be problematic unless Federal gasoline taxes were dramatically increased as much as $0.40 per gallon.  U.S. Department of Transportation Secretary Mary Peters led a minority report that argued for radical changes in the transportation funding process.

While we’re not taking sides on who has the best idea, we urge the reader to consider how difficult it will be to raise gasoline taxes at a time of economic distress and roller-coaster crude oil prices.  It’s one thing to take fewer trips to the grocery store; it’s altogether another matter for truckers to pay on top of already high costs for diesel fuel just to keep their rigs running.

In a 2005 study, the American Association of State Highway Transportation Officials (AASHTO) (8) called extending service life its #1 Engineering Grand Challenge  (9).  This year the Transportation Research Board (TRB) approved a new Joint Committee for Bridge Preservation.  Both of these actions show a growing consensus to safely extend the operating life of bridges.  The engineering community sees the issues clearly; the political process takes a bit longer.

Shortly after the I-35W bridge collapse, Congressman James L. Oberstar, Chairman of the House Transportation & Infrastructure (T&I) Committee, held hearings to address the national problem of structurally deficient bridges.  His initial Bill called for $25 billion dollars in funding to address the U.S.bridge problem on the National Highway System (NHS) (10).  This Bill was quickly reduced to $1 billion dollars because of Congressional and Administration resistance on the cost.  Despite the resistance, the House overwhelming passed HR 3999 in July.  Called the National Highway Bridge Reconstruction and Inspection Act, its key provisions include better inspector training, a risk adjusted prioritization process, and a $5 million dollar demonstration program for the use of advanced condition assessment technology.  At this writing, the Bill (SB 3338) is being considered by the Senate Subcommittee on Transportation and Infrastructure.

It seems highly likely that the new Administration will cooperate with Congress to pass the National Highway Bridge Reconstruction and Inspection Act AND provide stimulus funding for more local bridge projects.  While the merits of Federal bridge funding in the form of a stimulus will be intensely debated, we are concerned that Federal funding of this nature will be rushed and dedicated to fixing theU.S. structurally deficient bridge problem by blunt force instead of a scalpel.  The problem can and should be addressed with more engineering content and less economic and political heroics.



Defining the Challenge


A proposal to replace all 70,000+ structurally deficient U.S. bridges would be met in many quarters with cheers.  However, before launching into a program that will not only be costly, but may not be necessary, let’s revisit the basics:

    • The NBIS visual inspection protocol has conservatively overstated the number of structurally deficient bridges that need replacement.
    • Continued reliance on visual inspection and overly conservative analytics compound the problem.
    • States and local bridge owners simply cannot afford to replace every structurally deficient bridge.
    • The federal budget is so overwhelmed with non-discretionary funding, bailouts, and other financial commitments that a big slug of transportation funding from Washington DC is unlikely and perhaps unwise.
    • Commercial technology is available, but underutilized, to definitively determine which bridges must be replaced and which bridges can be rehabilitated instead of replaced.

The following examples are worth consideration as support for our proposal:

Example #1:  A Southwestern city used a novel rehabilitation process instead of replacing a bridge over a multi-mile long canal.  They proved the merit of this process by using an advanced condition assessment technology to objectively demonstrate that the bridge was strengthened.  Fourteen more bridges are in the queue to use this same approach, eventually saving the city nearly $45 million dollars.

Example #2:  A Northeastern Turnpike Commission employed advanced condition assessment technology to ascertain the need for an $875,000 steel repair program, recommended as a result of a visual inspection.  The technology conclusively showed the steel repair program was unnecessary and further highlighted the need to repair another problem which was not delineated on the visual inspection report.

Example #3:   A Southeastern DOT recently completed a study using advanced condition assessment technology.  Load testing was conducted on ten (10) randomly selected structurally deficient short-span bridges across the state.  The study showed (using HS-20 loading criteria) that allowable weight increases without additional repairs were reasonable for all ten bridges, some more than double what traditional analyses showed.

What remains difficult for those who are responsible for bridge inspection and evaluation is enthusiastic adoption of fully commercialized advanced condition assessment technology.  While conventional wisdom suggests use of this technology will result in added cost, technology practitioners and first hand experience suggest that bridge owners (and the federal government as the major funding source) can reap substantial returns on investment by employing better technology.



The Proposed Solution


Instead of authorizing major new Federal spending to fix the ill-defined U.S. bridge problem in the context of an economic stimulus, we advocate a four step approach:

    •  Step #1:  When a bridge is classified as structurally deficient, or has a sufficiency rating below 50 (eligible for replacement), require owners through use of targeted financial incentives to employ technically appropriate advanced condition assessment technology to determine the actual condition of the bridge.
    •  Step #2:  Have a third party engineering firm confirm actual bridge condition after evaluating the results of advanced condition assessment technology and certify the need for replacement instead of maintenance or rehabilitation.
    •  Step #3:  To provide the owner with a sizeable financial incentive to adopt advanced condition assessment technology and third party certification, the federal share for bridge projects should be increased from 80% to 85% of the total cost for those bridges that must be replaced, and from 80% to 90% of the total cost for bridges that can be rehabilitated.
    •  Step #4: For those bridges that must be replaced, a national risk adjusted priority system (as called for in HR 3999) should be used to properly apply and allocate limited funding to the most pressing needs, instead of a political and pork-laden prioritization process.



An Example


Assume a bridge is programmed to be replaced for $10 million.  Under existing funding programs, the local owner contribution will be $2 million and the federal contribution will be $8 million.  If the bridge must be replaced, assume a 15/85 split in funding. If the bridge can be rehabilitated, assume a 10/90 split in funding to provide owners with a significant incentive.  Finally, assume the owner’s cost of using advanced condition assessment technology will be $150,000 (typical for long-span bridges).  There are only three outcomes to consider in this example: replacement, rehabilitation, or no action necessary.


Outcome #1 – No Action: The bridge is found to be in acceptable condition and does not need rehabilitation or replacement.

Outcome #2 – Rehabilitation: The bridge can be satisfactorily rehabilitated instead of replaced.  Assume $3 million dollars for this action.

Outcome #3 – Replacement: The bridge, after a comprehensive assessment, must be replaced.



Assessment  Cost


 Construction Cost

Savings Over Replacement


Total Cost

No Action Required
Owner contribution  $        150,000


 $                  –  $          150,000  $       1,850,000
Federal contribution


 $                  –  $                    –  $       8,000,000
Total construction cost  $                  –
Owner contribution  $        150,000


 $        300,000  $          450,000  $       1,550,000
Federal contribution


 $     2,700,000  $       2,700,000  $       5,300,000
Total construction cost  $     3,000,000
Owner contribution  $        150,000


 $     1,500,000  $       1,650,000  $                    –
Federal contribution


 $     8,500,000  $       8,500,000  $                    –
Total construction cost  $   10,000,000



Using a statistical expected value analysis, assume Outcome #1 has a 20% probability of occurrence; Outcome #2 has a 20% probability and Outcome #3 has a 60% probability.  Therefore, the expected costs for both the owner and federal contribution are as follows:

  The Owner’s Expected Cost is $1,110,000; or nearly 50% less than the cost of the traditional funding approach.

 The Federal Expected Cost is $5,640,000; or about 30% less than the cost of the traditional funding approach.

This example shows that safely deferring replacement on only four in ten structurally deficient bridges has a robust financial impact for both local owners and the federal budget by reducing the expected cost of unnecessary actions.  The inescapable conclusion can be simply stated:




Summary and Conclusions


The inherent variability and subjectivity in the visual condition assessment protocol, as stated in the 2000 Public Roads (4) article and the 2004 Journal of Bridge Engineering (11) article, make optimized bridge management exceedingly difficult and may result in unnecessary rehabilitation or replacement projects.

Since state/county/city owners and the federal government cannot afford to conduct a bridge project before its time, they must adopt a process that rewards capturing and utilizing enhanced information, leading to improved financial outcomes.

Industry and owner experience with advanced condition assessment technologies continues to demonstrate that a significant percentage of bridges are in better condition than visual inspection indicates. However, we believe that the inevitable decision to aggressively adopt advanced condition assessment technologies will be the result of long-term financial constraints, not technological elegance.  There is simply too much financial gain to be ignored.  In an era of significant financial stress and anxiety, LifeSpan’s plan offers financial relief.

If structure owners and the federal government capture and employ more precise, objective information BEFORE they start allocating billions of dollars to repair or replace structurally deficient bridges, the taxpayers win.

And shouldn’t the taxpayers be the ultimate beneficiaries of any process that depends upon their hard earned money?




  1. www.bizjournals.com/Atlanta/stories/2008/09/22/daily85.html
  2. Wall Street Journal, October 11, 2008, Section A, page 7, “Democrats Discuss a Post-Election Stimulus Bill” by Greg Hitt.
  3. www.fhwa.dot.gov/bridge/nbis.htm
  4. http://www.tfhrc.gov/pubrds/marapr01/bridge.htm
  5. http://www.gobridges.com/article.asp?id=2810
  6. www.nytimes.com/2008/09/06/us/06highway.hmtl
  7. www.enr.construction.com/features/transportation/archives/080206-1.asp
  8. www.transportation.org
  9. http://cms.transportation.org/sites/bridges/docs/2005%20strategic%20plan%20-%20website%20version.pdf
  10. http://en.wikipedia.org/wiki/National_Highway_System_(United_States)
  11. http://cedb.asce.org/cgi/WWWdisplay.cgi?0410126



For more information, contact LifeSpan Technologies via the Web at www.lifespantechnologies.com,

or by calling 770-234-9494.