http://www.asce.org/pressroom/news/p....cfm?hdlid=132
Approved by the National Transportation Policy Committee on March 8, 2007
Approved by the Policy Review Committee on March 9, 2007
Adopted by the Board of Direction on April 24, 2007
Policy
For the continued safety of the nation's bridges, the American Society of Civil Engineers (ASCE) advocates that a bridge safety program for both public and private bridges be established, fully funded and consistently operated to upgrade or replace deficient bridges and to properly maintain all others. This program should preserve full functionality of all bridges to support the operation of safe, reliable and efficient transportation systems, and to allow these systems to be utilized to their full capacity. Such programs as a minimum should include:
* Regular programs of inspection and evaluation that incorporate state-of-the-art investigative and analytical techniques, especially of older bridges which were not designed and constructed to current design loading and geometric standards;
* Posting of weight and speed limits on deficient structures;
* Implementing and adequately funding regular system-wide maintenance programs that are the most cost-effective means of ensuring the safety and adequacy of existing bridges;
* Establishing a comprehensive program for prioritizing and adequately funding the replacement of functionally obsolete and structurally deficient bridges; and
* Set a national goal that fewer than 15% of the nation's bridges be classified as structurally deficient or functionally obsolete by 2010.
Issue
A structurally deficient bridge may either be closed or restricted to light vehicles because of its deteriorated structural components. While not necessarily unsafe, these bridges must have limits for speed and weight. A functionally obsolete bridge has older design features and, while it is not unsafe for all vehicles, it cannot safely accommodate current traffic volumes, and vehicle sizes and weights. These restrictions not only contribute to traffic congestion, they will affect safe and efficient personal mobility and movement of goods and services. The restrictions may also result in such major inconveniences as school buses taking lengthy detours and increased response times for emergency vehicles required to use alternate routes. Additionally, such restrictions may adversely affect the performance of transportation systems in emergency situations or for disaster response.
Continued neglect and lack of adequate maintenance will ultimately result in higher annual life-cycle costs of bridges due to shortened service life. Therefore, investment to improve the condition and functionality of the nation's bridges will reduce the required investment in the future.
With funding made available under SAFETEA-LU and its preceding Transportation Funding Bills, there has been some improvement in the condition and performance of the transportation infrastructure. As of 2005, 156,335 of the nation's 595,363 bridges, or 26.3%, were structurally deficient or functionally obsolete, as compared to 34.6% of all bridges in 1992. However, despite this improvement, functionally obsolescent or structurally deficient bridges on the nation's transportation systems continue to constitute significant potential hazards which may jeopardize the safe, reliable and efficient operation of these.
To simply maintain the current condition of these bridges will require an annual $7.3 billion (2000 dollars) investment. To eliminate all bridge deficiencies will require $9.4 billion (2000 dollars) annually for a period of 20 years. Total bridge expenditure by all levels of government for capital outlays (including system preservation and system expansion) was at $8.8 billion in 2003. Additional funding beyond that level will therefore be needed to continue to reduce the backlog of structurally deficient bridges, and prevent more bridges from becoming structurally deficient.
Rationale
The safety, functionality, and structural adequacy of bridges are key components necessary to support and ensure the safe, reliable and efficient operation of transportation infrastructure and systems which provide mobility of people and the movement of goods and services. This policy establishes the minimum bridge safety program components necessary for both public and private bridges to ensure an adequate and economical program for the inspection, evaluation, maintenance, rehabilitation, and replacement of our nation's bridges.
Approved by the National Transportation Policy Committee on March 8, 2007
Approved by the Policy Review Committee on March 9, 2007
Adopted by the Board of Direction on April 24, 2007
Policy
For the continued safety of the nation's bridges, the American Society of Civil Engineers (ASCE) advocates that a bridge safety program for both public and private bridges be established, fully funded and consistently operated to upgrade or replace deficient bridges and to properly maintain all others. This program should preserve full functionality of all bridges to support the operation of safe, reliable and efficient transportation systems, and to allow these systems to be utilized to their full capacity. Such programs as a minimum should include:
* Regular programs of inspection and evaluation that incorporate state-of-the-art investigative and analytical techniques, especially of older bridges which were not designed and constructed to current design loading and geometric standards;
* Posting of weight and speed limits on deficient structures;
* Implementing and adequately funding regular system-wide maintenance programs that are the most cost-effective means of ensuring the safety and adequacy of existing bridges;
* Establishing a comprehensive program for prioritizing and adequately funding the replacement of functionally obsolete and structurally deficient bridges; and
* Set a national goal that fewer than 15% of the nation's bridges be classified as structurally deficient or functionally obsolete by 2010.
Issue
A structurally deficient bridge may either be closed or restricted to light vehicles because of its deteriorated structural components. While not necessarily unsafe, these bridges must have limits for speed and weight. A functionally obsolete bridge has older design features and, while it is not unsafe for all vehicles, it cannot safely accommodate current traffic volumes, and vehicle sizes and weights. These restrictions not only contribute to traffic congestion, they will affect safe and efficient personal mobility and movement of goods and services. The restrictions may also result in such major inconveniences as school buses taking lengthy detours and increased response times for emergency vehicles required to use alternate routes. Additionally, such restrictions may adversely affect the performance of transportation systems in emergency situations or for disaster response.
Continued neglect and lack of adequate maintenance will ultimately result in higher annual life-cycle costs of bridges due to shortened service life. Therefore, investment to improve the condition and functionality of the nation's bridges will reduce the required investment in the future.
With funding made available under SAFETEA-LU and its preceding Transportation Funding Bills, there has been some improvement in the condition and performance of the transportation infrastructure. As of 2005, 156,335 of the nation's 595,363 bridges, or 26.3%, were structurally deficient or functionally obsolete, as compared to 34.6% of all bridges in 1992. However, despite this improvement, functionally obsolescent or structurally deficient bridges on the nation's transportation systems continue to constitute significant potential hazards which may jeopardize the safe, reliable and efficient operation of these.
To simply maintain the current condition of these bridges will require an annual $7.3 billion (2000 dollars) investment. To eliminate all bridge deficiencies will require $9.4 billion (2000 dollars) annually for a period of 20 years. Total bridge expenditure by all levels of government for capital outlays (including system preservation and system expansion) was at $8.8 billion in 2003. Additional funding beyond that level will therefore be needed to continue to reduce the backlog of structurally deficient bridges, and prevent more bridges from becoming structurally deficient.
Rationale
The safety, functionality, and structural adequacy of bridges are key components necessary to support and ensure the safe, reliable and efficient operation of transportation infrastructure and systems which provide mobility of people and the movement of goods and services. This policy establishes the minimum bridge safety program components necessary for both public and private bridges to ensure an adequate and economical program for the inspection, evaluation, maintenance, rehabilitation, and replacement of our nation's bridges.
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Someone slipped up on the integrity inspection of the collapsed bridge in Minneapolis. Judging from the photos and videos of the accident scene, it is most apparent and evident that the vehicular traffic on that bridge was beyond the prescribed limit for that particular bridge, as weight would dictate. Bridges are to be inspected at timely intervals to determine the structural integrity of the bridge.
I know of certain bridges in the area that have been determined to be less than adequate for regular daily traffic, and signage has been placed to advise the motorist of an impending perilous driving situation.
In the article posted above, and at the link provided, you will find a variety of procedures used by the DOT to insure bridge safety.
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