49 CFR § 299.311 - Track geometry; general.
---
identifier: "/us/cfr/t49/s299.311"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 299.311 - Track geometry; general."
title_number: 49
title_name: "Transportation"
section_number: "299.311"
section_name: "Track geometry; general."
chapter_name: "FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
part_number: "299"
part_name: "TEXAS CENTRAL RAILROAD HIGH-SPEED RAIL SAFETY STANDARDS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 20103, 20107, 20133, 20141, 20302-20303, 20306, 20701-20702, 21301-21302, 21304; 28 U.S.C. 2461, note; and 49 CFR 1.89."
regulatory_source: "85 FR 69731, Nov. 3, 2020, unless otherwise noted."
cfr_part: "299"
---
# 299.311 Track geometry; general.
If the values listed in the following table are exceeded, the railroad shall initiate remedial action. A reduction in operating speed so that the condition complies with the limits listed for a lower speed shall constitute bringing the track into compliance.
Table 1 to § 299.311
| Track geometry parameter (millimeter (mm)) | Track class | H0 | H1 | H2 | H3 | H4 | H5 | H6 | H7 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Gauge is measured between the heads of the rails at right angles to the rails in a plane 14 mm (0.55 inches) below the top of the rail head and may not exceed— | Min. | 1429 | 1429 | 1429 | 1429 | 1429 | 1429 | 1429 | 1429 |
| | Max. | 1454 | 1454 | 1454 | 1454 | 1454 | 1454 | 1454 | 1454 |
| The deviation from uniformity of the mid-chord offset on either rail for a 10 meter (m) chord (alignment) may not be more than— | 10 m chord | 38 | 31 | 31 | 14 | 12 | 10 | 8 | 7 |
| The deviation from uniform profile on either rail at the mid-ordinate of a 10 m chord (surface) may not be more than— | 10 m chord | 40 | 40 | 40 | 27 | 22 | 18 | 15 | 13 |
| The deviation from uniform crosslevel at any point on tangent and curved track may not be more than— | | 50 | 26 | 26 | 22 | 18 | 14 | 9 | 9 |
| The difference in crosslevel between any two points 2.5 meters (8.2 feet) apart (twist) may not be more than— | 2.5 m | 26 | 26 | 26 | 22 | 18 | 14 | 9 | 9 |
| Uniformity for alignment at any point along the track is established by averaging the measured mid-chord offset values for a 10 m (32.8 feet) chord for nine consecutive points that are centered around that point and spaced at 2.5 m (8.2 feet) intervals. | | | | | | | | | |