# Maximum allowable operating speed.

- **operation:** document
- **citation:** 49 CFR 174.86
- **title:** Maximum allowable operating speed.
- **source type:** regulation
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** current
- **official:** true
- **published on:** Not available
- **effective on:** 2026-08-18
- **summary:** (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph) for shipments by rail.

(b) For trains transporting any loaded, placarded tank cars containing a material
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/49-cfr-174-86.json
- **markdown:** https://regulus.evalyn.ai/document/49-cfr-174-86.md
- **app url:** https://regulus.evalyn.ai/document/49-cfr-174-86
- **source url:** https://www.ecfr.gov/on/2026-08-18/title-49/section-174.86
**body:**

(a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph) for shipments by rail.

(b) For trains transporting any loaded, placarded tank cars containing a material poisonous by inhalation, the maximum allowable operating speed may not exceed 80.5 km/hour (50 mph) for shipments by rail.

[74 FR 1801, Jan. 13, 2009]
- **truncated:** false
- **body characters:** 452