California Wildfire Closures and Truck Rerouting Under HOS Rules

When a wildfire closes a road, a driver has to find a way through and still account for the delivery appointment. A detour suggested by a navigation app may have height or weight restrictions that rule it out for this truck. Once safely parked, tell dispatch which stretch is closed and how much duty and driving time you have left. Before deciding whether to wait or reroute, check each leg against the truck’s dimensions and weight, and identify a safe place to stop.

Respond to smoke and evacuation orders

Slow down and use extra caution when smoke reduces visibility. Under 49 CFR § 392.14, if conditions become too dangerous to operate safely, you must stop operating until it is safe to continue. If stopping immediately would increase the danger to the people in the vehicle, you may proceed to the nearest place where they can be safe. Follow closure and evacuation orders at the scene, even if that means missing the delivery appointment.

Once safely parked, use the California Department of Transportation’s QuickMap or its highway conditions lookup to check the road number, direction of travel, limits of the closure and time of the last update. Include the time you checked in any screenshot you send to dispatch. An old screenshot cannot establish that the road is still open.

Check the entire detour for truck access

The QuickMap FAQ explains that QuickMap provides road conditions and is not a navigation service. An open road may still be restricted for your vehicle. Turn on the California Truck Network layer under commercial vehicles to check the route designation on state highways.

Give dispatch the vehicle combination, dimensions and actual load before checking the route. Go through the proposed detour one segment at a time for height, weight and access restrictions. Include the local roads you will use after leaving the state highway. If access on a local road is unclear, confirm it with the agency responsible for that road.

Routes designated for STAA trucks and California Legal trucks serve different vehicle configurations. Match the designation to your equipment. On a Kingpin-to-Rearmost-Axle (KPRA) Advisory Route, look up the advisory distance for that road and compare it with the distance from your trailer’s kingpin to its rearmost axle.

For an oversize or overweight vehicle operating under a transportation permit, check the route authorized on the permit. If that route is closed, dispatch should contact the permitting agency to find out whether an amendment or separate authorization is needed. See the transportation permits page.

If driving time is running short, establish when the closure became foreseeable

The limits below apply to drivers subject to the federal interstate hours-of-service rules for property carriers. Check California requirements separately for purely intrastate operations.

Whether a delay qualifies for the adverse driving conditions exception depends on whether the closure could reasonably have been anticipated. Under 49 CFR § 395.2, consider what the driver knew before starting the duty day or resuming driving after a qualifying rest break, and what the motor carrier knew before dispatch. If a closure notice was already in effect before departure, the fact that the detour took longer than expected does not by itself justify using the exception.

When the conditions are met, 49 CFR § 395.1(b) allows up to two additional hours of driving time and up to two additional hours in the driving window to complete the trip or reach a safe location. The trip must have been feasible within the normal limits before the unexpected conditions disrupted it. For a property-carrying driver ordinarily subject to an 11-hour driving limit and a 14-hour window, the maximums under this exception are 13 and 16 hours, respectively.

Check cumulative hours as well. The hours-of-service guide (PDF) explains that the exception does not extend the 60-hour limit in seven days or the 70-hour limit in eight days. Other applicable break and safety requirements still apply.

If you still cannot reach safe parking within the applicable limits, work with dispatch to revise the plan. Stop driving if fatigue affects your ability to drive safely, even if time remains on your clock.

Emergency conditions and direct relief have separate requirements

Paragraph (b)(2) of the same section addresses emergency conditions. If an emergency prevents completion of a run that could reasonably have been completed as planned, a driver may complete that run under this provision. Assess the event and the trip against its own requirements, separately from the two-hour adverse driving conditions exception. A wildfire along the route does not by itself authorize unrestricted driving to finish a delivery.

If the carrier is providing direct assistance in a relief effort, use the Federal Motor Carrier Safety Administration’s emergency declarations page to read the applicable declaration and any updates. Under 49 CFR § 390.23, the scope and duration of relief depend on who issued the declaration. Check the geographic area, effective period, type of transportation covered and specific provisions waived. Ordinary freight does not qualify for relief simply because it passes through a disaster area.

Record the change before planning the rest of the trip

Keep the time you first learned of the closure, the official notice, the original plan and the hours you had left. Record where you decided to wait or which route you took. If you use the adverse driving conditions exception, annotate the specific circumstances in the electronic logging device (ELD). Record waiting time according to your actual duties. Traffic delays are not automatically off-duty time.

Under the official personal conveyance guidance, personal conveyance is personal use of the vehicle after the driver has been relieved of work responsibilities. A detour to continue a delivery is still work and cannot be logged as personal conveyance to gain driving time. An ELD annotation explains what happened, but the facts determine whether an exception applies. If the route is unconfirmed, hours are insufficient or the driver is fatigued, dispatch should arrange a safe place to wait, change the appointment or find other transportation that can complete the trip within the rules.

Disclaimer. This article draws on public information from Caltrans, FMCSA and the Code of Federal Regulations, checked against official pages accessible on September 29, 2026. It is for general reference and does not constitute legal advice, a determination of an individual driver’s hours of service or authorization to use a specific route. Road restrictions, emergency declarations and regulations may change. Follow current official documents, lawful directions at the scene and the conditions of the actual trip. Vehicle dimensions, load, permits and driver logs affect the choice of route and the applicability of exceptions. Contact the responsible agency or a qualified professional if in doubt. The author and publisher accept no liability for losses arising from misuse of this information or its application outside the conditions described.

California Department of Transportation. “CA Truck Network.” Accessed 29 Sept. 2026.

California Department of Transportation. “California Highway Information.” Accessed 29 Sept. 2026.

California Department of Transportation. “QuickMap Frequently Asked Questions.” Accessed 29 Sept. 2026.

California Department of Transportation. “Transportation Permits (Oversize/Overweight Vehicles).” Accessed 29 Sept. 2026.

Federal Motor Carrier Safety Administration. “Emergency Declarations, Waivers, Exemptions and Permits.” Accessed 29 Sept. 2026.

Federal Motor Carrier Safety Administration. “Interstate Truck Driver’s Guide to Hours of Service for Property Carriers.” Apr. 2022. Accessed 29 Sept. 2026.

Federal Motor Carrier Safety Administration. “Personal Conveyance.” 12 Feb. 2019. Accessed 29 Sept. 2026.

United States, Department of Transportation. “49 CFR § 390.23: Automatic Relief from Regulations.” Electronic Code of Federal Regulations. Accessed 29 Sept. 2026.

United States, Department of Transportation. “49 CFR § 392.14: Hazardous Conditions; Extreme Caution.” Electronic Code of Federal Regulations. Accessed 29 Sept. 2026.

United States, Department of Transportation. “49 CFR § 392.3: Ill or Fatigued Operator.” Electronic Code of Federal Regulations. Accessed 29 Sept. 2026.

United States, Department of Transportation. “49 CFR § 395.1: Scope of Rules in This Part.” Electronic Code of Federal Regulations. Accessed 29 Sept. 2026.

United States, Department of Transportation. “49 CFR § 395.2: Definitions.” Electronic Code of Federal Regulations. Accessed 29 Sept. 2026.

United States, Department of Transportation. “49 CFR § 395.3: Maximum Driving Time for Property-Carrying Vehicles.” Electronic Code of Federal Regulations. Accessed 29 Sept. 2026.