# Regulatory Relief To Allow Speeds Up to 45 MPH for Non-Traversable Curbs
> **US Department of Transportation** · Final rule. · Published 2026-04-28 · Effective 2026-05-28 · 91 FR 22738
## Document
- **Document number:** 2026-08258
- **Category:** other
- **Sub-agency:** US Department of Transportation
- **Federal Register citation:** 91 FR 22738
- **CFR reference:** 49 CFR 222
- **Publication date:** 2026-04-28
- **Effective date:** 2026-05-28
- **DOT docket:** Docket No. FRA-2025-0120
## Abstract

This rule revises the definition of a non-traversable curb in FRA's train horn regulation in conformance with five longstanding FRA waivers that allow highway speeds up to 45 miles per hour (mph) where these highway curbs are present in quiet zones established and maintained in accordance with the regulation.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2026/04/28/2026-08258/regulatory-relief-to-allow-speeds-up-to-45-mph-for-non-traversable-curbs)
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