Pre-existing Supplementary Safety Measure Law and Legal Definition

According to 49 CFR 222.9 [Title 49 – Transportation; Subtitle B -- Other Regulations Relating to Transportation; Chapter II -- Federal Railroad Administration, Department of Transportation; Part 222 -- Use of Locomotive Horns at Public Highway-Rail Grade Crossings; Subpart A – General], Pre-existing Supplementary Safety Measure (Pre-existing SSM) means “a safety system or procedure established in accordance with this part before December 18, 2003 which was provided by the appropriate traffic control or law enforcement authority responsible for safety at the highway-rail grade crossing. These safety measures must fully comply with the SSM requirements set forth in appendix A of this part. The calculation of risk reduction credit for qualifying pre-existing SSMs is addressed in appendix A.”