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What is the Adverse Driving Conditions Exception?

The adverse driving conditions exception allows property-carrying drivers who encounter unexpected driving conditions to extend their maximum 14-hour on-duty and 11-hour driving time periods (found in Section 395.3 of the Federal Motor Carrier Safety Regulations) when certain conditions are met. This post explains the details of this exception.

What is the purpose of the adverse driving conditions exception?

The purpose of this exception is to provide drivers who encounter previously unknown adverse driving conditions an additional two hours of time to complete their run for the day, or to reach a place offering safety for the commercial motor vehicle (CMV) driver, and security for the cargo, without penalty.

The two additional hours apply both to the driving time limitation and to the 14-hour driving window. For example, when using the adverse driving conditions exception, a driver may drive up to 13 hours within 16 hours of coming on duty.

When does the adverse driving condition exception apply?

The adverse driving conditions exception only applies if the adverse weather conditions or unusual road or traffic conditions were not known, or could not reasonably be known, to a driver immediately prior to beginning the duty day or immediately before beginning driving after a qualifying rest break or sleeper-berth period, or to a motor carrier immediately prior to dispatching the driver.

What are some examples of adverse driving conditions?

Examples include snow, ice, sleet, fog, or other adverse weather conditions, or unusual road or traffic conditions such as an accident.

However, things such as a forecasted snowstorm or typical rush hour traffic do not qualify as they could have been known or should have been anticipated (by way of basic trip planning).

How is compliance with the rules verified?

The regulations do not include any specific record-keeping requirements to verify compliance with the exception. However, drivers should include a detailed note on their log explaining the circumstances and why the exception is being used.

An auditor or inspector would have to independently investigate the reason given by the driver to establish the authenticity of the exception-induced event, and if it matches with the time the driver was dispatched.

The FMCSA has recommended that drivers notate the qualifying event in their logs as soon as it occurs, or closely afterwards, so that the driver can expedite any future roadside inspections and avoid on-duty or driving time violations.

If the adverse conditions last 2+ hours and the driver still runs out of time, may the driver continue driving?

No, the driver must stop driving even if it means they don’t complete their load for that day. However, if the driver must keep going to find a safe area to pull off the road, they should further annotate their logs to provide a clear explanation.