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Adjustment of Nationwide Significant Risk Threshold

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Federal Railroad Administration (FRA), Department of Transportation (DOT).


Notice of Adjustment of the Nationwide Significant Risk Threshold.


In accordance with Title 49 Code of Federal Regulations Part 222, Appendix D, FRA is updating the Nationwide Significant Risk Threshold (NSRT). This action is needed to ensure that the public has the proper threshold of permissible risk for calculating quiet zones established in relationship to the NSRT. This is the second update to the NSRT since the final rule, titled “Use of Locomotive Horns at Highway-Rail Grade Crossings,” was amended in response to petitions for reconsideration on August 17, 2006 (71 FR 47614). This notice announces that the NSRT has fallen from 19,047 to 17,610.


The effective date is May 28, 2008.

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Ronald Ries, Office of Safety, FRA, 1200 New Jersey Avenue, SE., Washington, DC 20590 (telephone: (202) 493-6299 or e-mail:; or Kathryn Shelton, Office of Chief Counsel, FRA, 1200 New Jersey Avenue, SE., Washington, DC 20590 (telephone: (202) 493-6038 or e-mail:

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The NSRT is simply an average of the risk indexes for gated public crossings nationwide where train horns are routinely sounded. FRA developed this risk index to serve as one threshold of permissible risk for quiet zones established under this rule across the Nation. Thus, a community that is trying to establish and/or maintain its quiet zone pursuant to 49 CFR Part 222 can compare the Quiet Zone Risk Index calculated for its specific crossing corridor to the NSRT to determine whether sufficient measures have been taken to compensate for the excess risk that results from prohibiting routine sounding of the locomotive horn. (In the alternative, a community can establish its quiet zone in comparison to the Risk Index With Horns, which is a corridor-specific measure of risk to the motoring public when locomotive horns are routinely sounded at every public highway-rail grade crossing within the quiet zone.)

In 2006, when the final rule, titled “Use of Locomotive Horns at Highway-Rail Grade Crossings” was amended, the NSRT was 17,030 (71 FR 47614, August 17, 2006). In 2007, FRA recalculated the NSRT to be 19,047 (72 FR 14850, March 29, 2007.)


Using collision data from 2002 to 2006, FRA has recalculated the NSRT based on formulas identified in 49 CFR Part 222, Appendix D. In making this recalculation, FRA noted that the total number of gated, nonwhistle ban crossings was 38,420.

Applying the fatality rate and injury rate to the probable number of fatalities and casualties predicted to occur at each of the 38,420 identified crossings and the predicted cost of the associated injuries and fatalities, FRA calculates the NSRT to be 17,610.

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Issued in Washington, DC on May 21, 2008.

Grady C. Cothen, Jr.,

Deputy Associate Administrator for Safety Standards and Program Development.

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[FR Doc. E8-11848 Filed 5-27-08; 8:45 am]