Over the years, Congress has passed exemptions from federal truck size and weight limits for specific states and commodities. The result has been added dangers to our roads, increased wear and tear on our pavements and bridges, and more difficulty in enforcing a complex set of limits—not to mention pressure on other states to request their own exemptions. There have been no fewer than 25 exemptions granted by Congress in recent years. These exemptions (complete list on pages 3 and 4) range from allowing much heavier trucks on all Interstate highways in an individual state to exceptions for specific routes. These exemptions also may cover all commodities or be limited to trucks hauling a specific commodity, such as milk or concrete panels or sugarcane—and cover truck configurations from single-trailer to triple-trailer trucks.

While varying widely, what special exemptions have in common is that they undergo little or no review by Congress before they are approved. With only a few exceptions, there has been no research to evaluate the outcomes of exemptions on safety or infrastructure once adopted.

Importantly, the U.S. Department of Transportation has consistently opposed this kind of “piecemeal approach” to highway policy. Here is what the Department said about special exemptions in a 2004 report:

The Department does not support this kind of piecemeal approach to truck size and weight policy. It makes enforcement and compliance with truck size and weight laws more difficult, it often contributes little to overall productivity, it may have unintended consequences for safety and highway infrastructure, and it reduces the willingness to work for more comprehensive solutions that would have much greater benefits.[1]

And, in its 2016 Final Report to Congress, the Department again made clear its position:

As such, the Department stresses that no changes in the relevant Federal truck size
and weight laws and regulations should be made until these limitations are overcome. Despite recent Congressional action approving additional size and weight exceptions and waivers on a piecemeal and nationwide basis, DOT recommends a thoughtful approach to future policymaking.[2]

 

Added dangers and damaged infrastructure

Bigger trucks allowed by exemptions endanger motorists:

  • Heavier trucks have higher crash rates than 80,000-pound, five-axle trucks.[3]
  • Heavier trucks cause more severe crashes and are more likely to roll over[4].
  • Adding weight to a truck causes additional wear and tear on key safety components.[5]

Bigger trucks allowed by exemptions damage local infrastructure:

  • Heavier trucks negatively impact bridges, requiring costly repairs or replacement.[6]
  • Exemptions often increase truck weight without adding axles, increasing pavement and bridge deck damage.

Difficulty with enforcement and compliance

Law enforcement departments have limited resources to enforce current truck size and weight limits, so adding new exemptions would further stretch their resources. Providing adequate training is already difficult, and re-education on these arbitrary exceptions would be even more problematic. Also, exemptions may necessitate costs associated with additional equipment, information technology and human resources, burdening county and local budgets.[7]

Exemptions cannot be viewed in isolation – they create problems for other states

Trucks operating under these exemptions would not be limited to Interstates in individual states where they apply. Heavier trucks will invariably spread to neighboring states, increasing the challenges of enforcement in those states. Special exemptions also apply pressure on neighbor states to consider additional exceptions for other commodities or routes in order to remain competitive. History shows that once an exemption is allowed, interests without allowances demand they also be permitted to use heavier trucks, causing a “snowball effect.”

Reject special exemptions and support further research

Permitting bigger-truck routes and commodities in a piecemeal fashion is dangerous, costly and difficult to enforce[8]. Congress should adopt no new laws allowing state specific or commodity specific exemptions for bigger trucks. The impacts of special exemptions on safety, infrastructure, enforcement and productivity should be studied as part of any further research conducted by USDOT.

 

List of Special Exemptions

Truck Weight Standards, 23 US Code Sec. 127

The federal gross vehicle weight (GVW) maximum for Interstate highways is 80,000 pounds.

  • Trucks hauling two or more concrete panels in Colorado are nondivisible loads
  • Trucks hauling sugarcane during harvest season in Louisiana weighing 100,000 pounds
  • Two Interstate routes exempted from federal GVW limits in Iowa
  • 99,000-pound GVW limit on parts of the Interstate system in New Hampshire
  • 99,000-pound GVW limit on parts of the Interstate system in Vermont
  • 100,000-pound GVW limits on the Maine Turnpike
  • Trucks hauling milk nationwide are nondivisible loads
  • 117,000-pound GVW limits on Interstates in Wyoming
  • Triple-trailer trucks on a short segment off of the Ohio Turnpike
  • Trucks hauling coal, logs and pulpwood are exempt for a stretch of Maryland highway
  • Heavier trucks allowed on stretch of reclassified Interstate highway in Pennsylvania
  • Heavier trucks allowed on stretch of reclassified Interstate highway in Mississippi
  • Heavier trucks allowed on stretch of reclassified Interstate highway in Wisconsin
  • Heavier trucks allowed on stretch of reclassified Interstate highway in Kentucky
  • Heavier trucks allowed on parts of reclassified Interstate highways in Texas
  • 98,000-pound GVW limits for covered log trucks on part of an Interstate in Wisconsin
  • 99,000-pound GVW limits for covered log trucks on part of an Interstate in Arkansas
  • 99,000-pound GVW limits for covered log trucks on part of an Interstate in Minnesota
  • 82,000-pound GVW limits nationwide for natural gas or electric-powered trucks
  • 129,000-pound GVW limits for trucks on Interstates in Idaho
  • 129,000-pound GVW limits for trucks on Interstates in North Dakota

Truck Length Standards, 49 US Code Sec. 31111

  • Trucks hauling harvesters are exempt up to 81.5 feet long in Nebraska
  • Trucks hauling harvesters are exempt up to 81.5 feet long in Kansas
  • Trucks hauling sugar beets are exempt up to 82.75 feet long in Oregon
  • State laws are preempted from limiting truck length for automobile transporters, driveaway saddle-mount transporters, tow-away trailer transporters or maxi-cube vehicles

[1] U.S. Department of Transportation, 2004. Western Uniformity Scenario Analysis, pg. ES-11

[2] U.S. Department of Transportation, 2016. Comprehensive Truck Size and Weight Limits Final Report to Congress, pg. 21

[3] Ibid.

[4] USDOT; 2000. Comprehensive Truck Size and Weight Study

[5] USDOT; 2016. Comprehensive Truck Size and Weight Limits Study, Final Report to Congress

[6] Ibid.

[7] U.S. Department of Transportation, 2015. Comprehensive Truck Size and Weight Limits Study Compliance Comparative Analysis Technical Report, pg. 59

[8] USDOT; 2004. Western Uniformity Scenario Analysis: A Regional Truck Size and Weight Scenario Requested by the Western Governors’ Association