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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 Nationwide Significant Risk Threshold.


In accordance with Appendix D to Title 49 Code of Federal Regulations (CFR) part 222, Use of Locomotive Horns at Highway-Rail Grade Crossings, 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 third update to the NSRT, which is being increased to 18,775 from 17,610.


The effective date is September 1, 2009.

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Mr. Ronald Ries, Office of Railroad 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. (Alternatively, 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, Aug. 17, 2006). In 2007, FRA recalculated the NSRT to be 19,047 (72 FR 14850, Mar. 29, 2007). In 2008, FRA recalculated the NSRT to be 17,610 (73 FR 30661, May 28, 2008).


Using collision data from 2004 to 2008, FRA has recalculated the NSRT based on formulas identified in Appendix D to 49 CFR part 222. In making this recalculation, FRA noted that the total number of gated, non-whistle-ban crossings was 39,065.

Applying the fatality rate and injury rate to the probable number of fatalities and casualties predicted to occur at each of the 39,065 identified crossings and the predicted cost of the associated injuries and fatalities, FRA calculates the NSRT to be 18,775.

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Issued in Washington, DC, on August 25, 2009.

Jo Strang,

Associate Administrator for Railroad Safety/Chief Safety Officer.

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[FR Doc. E9-20966 Filed 8-31-09; 8:45 am]