Qualifying for a Quiet Zone

A Quiet Zone may be established without approval of the FRA
using one of the following criteria
:
  • Installation of
     one or more Supplementary Safety Measures (SSMs) at all public at-grade crossings within the Quiet Zone.
  • If
     Quiet Zone Risk Index is at or below Nationwide Significant Risk Threshold (NSRT) after any necessary SSMs are installed.
  • If Quiet Zone Risk Index
     is at or below Risk Index with Horns after any necessary SSMs are installed.
The NSRT is an average value established for all gated public crossings in the United States where train horns are sounded. It is updated annually by the FRA and published on the FRA website. Any Quiet Zones which qualify under this rule no longer qualify if a revised NSRT drops below the
Quiet Zone Risk Index
.
Local governments may also establish a Quiet Zone with approval of Alternative Safety Measures to be approved by application to the FRA.