# Expanding Certain Locomotive Wheel Set Diameter Variations

**Action Urgency Score:** 30/100

| Field | Value |
|---|---|
| Agency | Transportation Department; Federal Railroad Administration |
| Type | Final rule |
| Action | Final rule. |
| Published | 2026-08-31 |
| Effective | 2026-09-30 |
| Significant | No |
| CFR parts | 49 CFR 229 |
| Summary | This rule amends FRA's locomotive safety regulations to expand the maximum permitted variation in diameter for locomotive wheel sets using alternating current technology, in response to a Class I railroad's May 2019 petition for rulemaking and innovations in traction motor control. |
| Document number | 2026-17788 |

## Why this score
- Final rule.

Source: Federal Register API (Office of the Federal Register) (https://www.federalregister.gov/documents/2026/08/31/2026-17788/expanding-certain-locomotive-wheel-set-diameter-variations). Last refreshed: 2026-11-04T21:40:49.974Z.
Data from the Federal Register API; the published Federal Register document is authoritative. Informational only, not legal advice.