49 CFR § 299.313 - Track geometry; performance based.
---
identifier: "/us/cfr/t49/s299.313"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 299.313 - Track geometry; performance based."
title_number: 49
title_name: "Transportation"
section_number: "299.313"
section_name: "Track geometry; performance based."
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"
---
# 299.313 Track geometry; performance based.
(a) For all track of Class H4 and above, vibration in the lateral and vertical directions measured on the carbody of a vehicle representative of the service fleet traveling at a speed no less than 10 km/h (6.2 mph) below the maximum speed permitted for the class of track, shall not exceed the limits prescribed in the following table:
Table 1 to Paragraph (**a**)
| Lateral vibration | Vertical vibration |
| --- | --- |
| ≤ 0.35 g peak-to-peak | ≤ 0.45g peak-to-peak |
| 1 sec window | 1 sec window |
| excluding peaks < 50 msec | excluding peaks < 50 msec |
| Carbody accelerations in the vertical and lateral directions shall be measured by accelerometers oriented and located in accordance with § 299.337(c)(3). | |
| Acceleration measurements shall be processed through an LPF with a minimum cut-off frequency of 10 Hz. The sample rate for acceleration data shall be at least 200 samples per second. | |
| Peak-to-peak accelerations shall be measured as the algebraic difference between the two extreme values of measured acceleration in any 1-second time period, excluding any peak lasting less than 50 milliseconds. | |
(b) If the carbody acceleration requirements are not met on a segment of track, the segment of track is to be reclassified to the next lower Class of track for which it does meet the requirements of this part.