Table 1-2 Automated Track Inspection Program (ATIP) Exceptions(1) per 100 Miles: 2004-2014
|Total Per 100 Miles||38.0||36.1||26.3||28.7||33.7||27.9||24.8||14.5||14.1||77.6||44.0|
1 Exceptions mean track did not meet normal operation standards
KEY: ATIP = Automated Track Inspection Program
NOTES: The ATIP program does not provide a comprehensive evaluation of the national rail network on an annual basis due to the limited number of surveying cars. Inspection locations vary by year and are prioritized by factors such as safety risk analysis and operation types. The FRA implemented upgrades to the inspection and collection technology in the ATIP fleet in 2013 which allowed for increased sensitivity of exception detection. Multiple cars surveying except for 2005. Defects are briefly defined as variations from design values for the following track geometry properties:
Profile - rail surface elevations
Alignment - track direction (tangent or curvature)
Gage - distance between rails
Cross-level - elevation difference between the rails
Warp - maximum change in cross-level over a specified distance
Runoff - elevation (ramp) difference of a line along the top of the rail is used for the projection
Twist - rate of introduction and removal of cross-level on transitions from straight to curved track alignment
Limited Speed - reduced operating speed due to track geometry constraints
Detailed definitions and standards may be found in U.S. Department of Transportation, Federal Railroad Administration, Track and Rail and Infrastructure Integrity Compliance Manual, July 2012.
SOURCE: U.S. Department of Transportation, Federal Railroad Administration, Office of Safety, ATIP Statistics (June 15, 2015). Available at http://www.fra.dot.gov/ as of July 2015.