# Adverse driving conditions — Federal hours-of-service exemptions by commercial driver operation type

For Adverse driving conditions, cfr citation is 49 CFR 395.1(b)(1); who qualifies is a driver who encounters adverse driving conditions; what it exempts from is may drive and be permitted or required to drive a commercial motor vehicle for not more than two additional hours beyond the maximum allowable hours permitted under § 395.3(a) or § 395.5(a); radius or condition is not more than two additional hours; baseline limit (for context) is § 395.3(a): 11 hours of driving inside a 14-hour window, after 10 consecutive hours off duty, recorded from its source on 2026-08-28; source re-checked 2026-08-30.

- **Exemption:** Adverse driving conditions _(our reading, not quoted from the source)_
- **CFR citation:** 49 CFR 395.1(b)(1) _(our reading, not quoted from the source)_
- **Who qualifies:** a driver who encounters adverse driving conditions _(verified: appears in the quote below)_
- **What it exempts from:** may drive and be permitted or required to drive a commercial motor vehicle for not more than two additional hours beyond the maximum allowable hours permitted under § 395.3(a) or § 395.5(a) _(verified: appears in the quote below)_
- **Radius or condition:** not more than two additional hours _(verified: appears in the quote below)_
- **Baseline limit (for context):** § 395.3(a): 11 hours of driving inside a 14-hour window, after 10 consecutive hours off duty. _(our reading, not quoted from the source)_

## What the source says

> (1) Adverse driving conditions. Except as provided in paragraph (h)(3) of this section, a driver who encounters adverse driving conditions, as defined in § 395.2 , and cannot, because of those conditions, safely complete the run within the maximum driving time or duty time during which driving is permitted under § 395.3(a) or § 395.5(a) may drive and be permitted or required to drive a commercial motor vehicle for not more than two additional hours beyond the maximum allowable hours permitted under § 395.3(a) or § 395.5(a) to complete that run or to reach a place offering safety for the occupants of the commercial motor vehicle and security for the commercial motor vehicle and its cargo.

## Source

- https://www.ecfr.gov/current/title-49/subtitle-B/chapter-III/subchapter-B/part-395/subpart-A/section-395.1

Last verified: 2026-08-30. Review by: 2027-08-28.
Part of [Federal hours-of-service exemptions by commercial driver operation type](https://referencesource.org/federal-hours-of-service-exemptions-by-operation-type/).