U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 27, 2025
(a) Except as provided in paragraph (b) of this section, alinement may not deviate from uniformity more than the amount prescribed in the following table:
| Class of track | Tangent track | Curved track | |
|---|---|---|---|
| The deviation of the mid-offset from a 62-foot line 1 may not be more than—(inches) | The deviation of the mid-ordinate from a 31-foot chord 2 may not be more than—(inches) | The deviation of the mid-ordinate from a 62-foot chord 2 may not be more than—(inches) | |
| Class 1 track | 5 | 3 N/A | 5 |
| Class 2 track | 3 | 3 N/A | 3 |
| Class 3 track | 1
| 1
| 1
|
| Class 4 track | 1
| 1 | 1
|
| Class 5 track |
|
|
|
1 The ends of the line shall be at points on the gage side of the line rail, five-eighths of an inch below the top of the railhead. Either rail may be used as the line rail; however, the same rail shall be used for the full length of that tangential segment of the track.
2 The ends of the chord shall be at points on the gage side of the outer rail, five-eighths of an inch below the top of the railhead.
3 N/A—Not Applicable
(b) For operations at a qualified cant deficiency, E
| Class of track | Curved track | |
|---|---|---|
| The deviation of the mid-ordinate from a 31-foot chord 1 may not be more than—(inches) | The deviation of the mid-ordinate from a 62-foot chord 1 may not be more than—(inches) | |
| Class 1 track 2 | 3 N/A | 1
|
| Class 2 track 2 | 3 N/A | 1
|
| Class 3 track |
| 1
|
| Class 4 track |
|
|
| Class 5 track |
|
|
1 The ends of the chord shall be at points on the gage side of the outer rail, five-eighths of an inch below the top of the railhead.
2 Restraining rails or other systems may be required for derailment prevention.
3 N/A—Not Applicable
