Washington Logging Truck Permit Rules

Nov. 16, 2025, 10:18 a.m.
Washington State has one of the strongest forestry sectors in the U.S., and with that comes a unique set of permit rules for logging trucks. Whether you're hauling logs from timber sites to mills or moving equipment between forests, Washington’s regulations are strict and heavily enforced. Below is a complete guide to help carriers stay compliant.
Washington Logging Truck Permit

1. When Logging Trucks Need a Permit in Washington

Logging trucks generally require permits when:

  • Gross vehicle weight (GVW) exceeds legal limits

  • Axle weights exceed standard thresholds

  • The load overhangs beyond legal dimensions

  • Traveling on restricted routes or bridges

  • Operating during seasonal weight restrictions

Washington does allow a special logging overweight permit for certain operations, but you must meet strict conditions.


2. Washington’s Special Overweight Permits for Log Trucks

Washington offers a “Special Logging Permit” (under WAC 468-38) for trucks hauling raw logs. This permit:

  • Allows increased gross weights above the standard 105,500 lbs, depending on axle configuration.

  • Applies to non-divisible loads only (logs are considered non-divisible).

  • Usually requires carriers to follow approved logging routes.

Key points:

  • Axle spacing must comply with WA bridge tables.

  • Loads must be secured per WAC 204-24.

  • Only applies to vehicles hauling raw forest products, not processed lumber.


3. Weight & Axle Requirements

Washington’s logging permits rely on specific axle formulas, including:

  • Maximum single axle: 22,000 lbs

  • Tandem axle: 43,000 lbs (with permit allowances for logging trucks)

  • Tridem axle: Up to 65,000 lbs with permits

  • Gross weight: Varies with axle count and spacing; must follow the WA Bridge Formula.

Logging trucks cannot exceed tire load ratings.


4. Dimension Rules for Logging Trucks

Logging trucks occasionally require permits when:

  • Rear overhang exceeds 15 ft

  • Overall height exceeds 14 ft

  • Width exceeds 8 ft 6 in

  • Length exceeds 41 ft for single units or 75 ft for combinations (with exceptions for pole or log-hauling trailers)

Most log trucks can operate legally without a dimension permit if their overhang is properly flagged and within allowable limits.


5. Load Securement Requirements

Washington requires:

  • At least two wrappers (tie-downs) for most log stacks

  • Additional wrappers depending on length, curvature, and stability of the logs

  • Center of gravity rules to prevent shifting

  • Compliance with FMCSA 393.116 for log securement

Violations are heavily enforced during WSP inspections.


6. Routing Restrictions

Logging trucks may face:

  • Seasonal closures on forest roads

  • Bridge and culvert limits on state or county routes

  • Restrictions during spring thaw in certain counties

  • Mandatory detours around weight-limited structures

Carriers must check WSDOT’s 511 travel advisory system and bridge weight maps before travel.


7. Seasonal Weight Restrictions

During freeze-thaw seasons, Washington often applies:

  • Reduced axle weight limits

  • Temporary prohibitions on heavy haul loads

  • County-managed weight restrictions on rural roads

Logging carriers operating in Eastern and Northern Washington are especially affected.


8. Permits for Off-Road and Forest Service Roads

If operating on:

  • US Forest Service roads → separate rules may apply

  • Private timber company lands → landowner-specific regulations

  • County-managed logging routes → coordinate with local public works departments

  • Tribal lands → tribal permits may be required


9. Escort/Pilot Car Requirements

Logging trucks rarely need pilot cars, but if the load becomes oversized (for example, long poles or overlength logs), Washington’s standard escort rules apply.

Typical triggers include:

  • Over 20 ft of rear overhang

  • Height exceeding 14 ft 6 in

  • Width over 11 ft (depending on route)


10. Enforcement & Penalties

Washington State Patrol enforces logging truck compliance through:

  • Roadside inspections

  • Weight checks at scales

  • Safety blitzes during peak logging season

Penalties can include:

  • Fines for overweight violations

  • Permit revocation

  • Out-of-service orders

  • Civil liability for infrastructure damage