What does the adverse driving conditions exception allow under 49 CFR 395.1(b)?

Short answer

The adverse driving conditions exception allows for the following:

1. Driving for not more than two additional hours beyond the maximum allowable hours

2. Completion of the run or reaching a place offering safety for the occupants and security for the vehicle and its cargo

3. Extension of the maximum driving time or duty time during which driving is permitted under 395.3(a) or 395.5(a)

The rule says

"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." (49 CFR 395.1(b)(1))

In plain English

The adverse driving conditions exception is a safety provision that allows drivers to extend their driving time or duty time by up to two hours if they encounter unexpected weather or road conditions that make it difficult to complete their run safely. This exception is meant to provide flexibility in emergency situations, but it's not a blanket exemption from hours-of-service rules. Drivers and motor carriers must still comply with all applicable regulations and ensure that the extension of driving time does not compromise safety.

What to do

• Monitor weather and road conditions before and during trips to anticipate potential adverse driving conditions
• Develop a plan for extending driving time or duty time if adverse conditions are encountered, including identifying safe places to stop or wait out the conditions
• Document the adverse driving conditions and the extension of driving time or duty time in the driver's log or electronic logging device
• Ensure that all drivers are trained on the adverse driving conditions exception and understand how to apply it safely and in compliance with regulations