Comprehensive Truck Size and Weight Limits Study - Volume 1: Technical Reports Summary

Chapter 1: Current Truck Size and Weight Regulations in the United States and Other Countries

Introduction and Context

This document is organized into three chapters. Chapter 1 describes current truck size and weight regulations in the United States, Mexico, Canada, the European Union, and Australia.

Chapter 2 discusses the technical scope and methodology used in assessing the impacts that trucks operating above current Federal size and weight limits compared to the impacts associated with trucks operating at or below current Federal limits. In this Chapter, the impacts that changes to U.S. Federal truck size and weight limits may be expected to have are assessed, including:

1. Shifts in truck types, roadways, and modes used;
2. Highway safety (truck crash rates, vehicle performance, and violation patterns);
3. Pavement service life;
4. Bridge performance; and
5. Enforcement program delivery and effectiveness.

It also discusses the approaches used to encourage public input and provides an overview of the study review process, including a peer review by the National Academy of Sciences, ongoing internal USDOT reviews, and a comprehensive examination of prior truck size and weight studies in the desk scans (literature searches). These prior studies form the foundation and provide a guide for the current study.

Finally, Chapter 3 summarizes the analytical results of each of the five technical study areas noted above. It includes information on the data and models used, the assumptions that were applied to each study area, and the limitations encountered during the analysis.

Background

Goods are moved throughout the United States on an extensive network of highways, railroads, waterways, and pipelines, as well as air-cargo routes. Each transportation mode plays a distinct role in moving goods, and multiple modes are used often to transport shipments; for example, most goods transported by air arrive at or are taken from the airport by trucks. Trucks move a substantial percentage of the tonnage and value of goods in our economy, which relies on dependable, quick, and efficient freight transportation to move goods to markets and link businesses to suppliers. Over the last two decades, increasing demand for freight services has put more pressure on our transportation system’s capacity and has heightened concerns about transportation reliability, safety, security, energy consumption, and impacts on the environment. The need to understand and address these concerns has become a priority for decision makers at all levels of government and in the private sector. A major safety concern relates to the mix of trucks and passenger vehicles competing for use of the highway system. Today’s fast-paced global economy requires just-in-time operations, bringing a greater number of trucks and passenger vehicles into close proximity. Another safety concern relates to whether an expansion of the highway network on which heavier and longer trucks can legally operate could expose the public to greater safety risks. The safety of the traveling public is the top priority of the USDOT and a major goal of public- and private-sector transportation programs. Many safety-related initiatives have been undertaken by the USDOT and other public sector transportation organizations, often in cooperation with the private sector, to mitigate the impacts of growing volumes of freight shipments on transportation safety. These initiatives include improved occupant protection equipment, enhanced enforcement, and hours-of-service regulations that specify rest requirements for truck drivers. Since 2000, truck-involved crashes have declined by 26 percent. Even so, in 2012 crashes involving large trucks claimed 3,921 lives. Of that total, 82 percent were occupants of other vehicles or bystanders, according to the National Highway Transportation Safety Administration (NHTSA).

The U.S. transportation system moves a massive volume of goods each year. Nearly 20 billion tons of goods valued at approximately $18 trillion were moved in 2012, according to the Federal Highway Administration’s (FHWA) Freight Analysis Framework (FAF).  This amounts to almost 54 million tons of freight moved every day. Trucks hauled approximately two-thirds of the total tonnage and value of goods moved in 2012. Moreover, trucks carried the greatest share of shipments moving 500 or fewer miles; rail and pipelines together moved more than half of all tons shipped distances between 750 miles and 2,000 miles. FAF forecasts show that freight volumes will grow to close to 29 billion tons, valued at approximately $39 trillion, by 2040. All indications are that trucks will continue to carry the largest share of freight in the near future (USDOT FHWA 2014).

To meet the growing demand for freight transportation services, the U.S. truck fleet has increased substantially both in number and average weight over the last 25 years. According to the latest Vehicle Inventory and Use Survey (VIUS), conducted by the Census Bureau, the number of heavy-heavy trucks (i.e., those weighing more than 26,000 lbs.) grew by nearly 50 percent from 1987 to 2002¹. Trucks weighing between 60,000 lbs. and 80,000 lbs. comprised the largest category in both number of trucks and in vehicle-miles traveled (VMT).

The growth in demand for goods also contributed to the increase in combination truck VMT by 15 percent from 2002 to 2012. Combination trucks are the various configurations of tractor-semitrailers and tractor-trailers operating on U.S. highways. Despite the overall growth in highway traffic over the past decade, combination truck VMT remains a relatively small share of total traffic, accounting for 5.5 percent in 2012. Nearly one-half of combination truck-miles occur on the Interstate System (USDOT FHWA 2014a and 2014b).

Freight volumes are forecast to continue growing, increasing 45 percent by 2040. This expected growth suggests that any changes in truck size or weight limits will only slow the increase in trucks on the road.

Truck Size and Weight Regulations

One of the MAP-21 study requirements directs the examination of the safety of truck size and weight standards that differ from those in the United States. Most countries regulate commercial vehicle size and weight by prescribing maximum and minimum limits. These limits are intended to protect equity in transport markets, ensure highway safety, and keep damage to transportation infrastructure within manageable bounds.

In general, size and weight standards are established at the national level, but States or provinces may allow heavier vehicles to operate on their roadways under special permits or exemptions. Larger vehicles are typically subject to route restrictions. In the United States, Federal weight limits apply only to the Interstate System. The maximum gross vehicle weight (GVW) ² of the most commonly used long-haul vehicles ranges from 80,000 lbs. (approximately 36.3 metric tonnes ³ on the U.S. Interstate System to 45-55 metric tonnes (roughly 99,208 lbs. to 121,254 lbs.) in Mexico, Canada, and Australia. Gross vehicle weight limits in European Union (EU) member States range from 40 metric tonnes (88,184 lbs.) in France and Germany to 50 metric tonnes (110,231 lbs.) in the Netherlands.

In addition to variations in weight allowances, some countries have different standards for their infrastructure, (matching bridge and pavement specifications to greater vehicle weights) and different regulatory requirements for vehicles and drivers.

Examples of several countries’ approaches to commercial vehicle size and weight regulations and their current truck weights and dimensions are presented below.

United States

Since 1956, the U.S. Federal Government has regulated commercial vehicle weight on the Interstate System. Before that time, the States established truck weight limits and continued to set weight limits off the Interstate System. (See Box 2 for a brief history of U.S. truck size and weight regulations.) The Federal Government also regulates the States’ ability to set limits on the dimensions for trucks defined as Surface Transportation Assistance (STAA) vehicles ⁴ as they travel on the National Network. The Federal Government does not have statutory authority to set weight limits for trucks on non-Interstate System roads. This authority rests with the States. Each State sets weight limits in some cases above Federal weight limits and in other cases below Federal limits. Through the use of “grandfathered rights,” 16 States have retained the right to continue the practice of permitting divisible load movements that exceed Federal weight limits on the Interstate System at the time when Federal regulations were enacted. All States have the authority to permit the movement of non-divisible loads ⁵ on both State roadways and the Interstate System. An electrical transformer is an example of a non-divisible load. Between 2008 and 2012, the total reported number of permits increased from 2.1 million to about 4.2 million.⁶

As shown in Table 1, non-divisible trip permits accounted for between 80 and 83 percent of total permits in each year while non-divisible annual permits accounted for six percent. Divisible trip permits accounted for two percent and divisible annual permits accounted for between nine and twelve percent over the 2008-2012 period. Several of the study’s scenario truck configurations are in current use in the United States. Specifically, the 88,000-lb., 91,000-lb., and 97,000- lb. GVW trucks operating under State-issued permits where grandfathered rights enable commercial motor vehicles to operate above Federal weight limits. The Scenario 4 truck configuration with a twin 33-ft. (2-S1-2) semitrailer/trailer is not currently in wide use in the United States.⁷

Table 1. Nationwide Number of Permits Issued for 44 Reporting States: 2008-2012

	Nationwide Number of Permits by Year 1 Percent Change of Permits from Previous Year
Permit Type	2008	2009	2010	2011	2012
Non-divisible trip	3,411,636	2,987,590 -14%	3,222,452 7%	3,446,444 6%	3,490,566 1%
Non-divisible annual	263,082	244,736 -7%	242,776 -1%	260,290 7%	272,939 5%
Divisible trip	65,401	89,703 27%	79,236 -13%	97,389 19%	88,918 -10%
Divisible annual	358,731	359,201 0%	503,871 29%	369,897 -36%	383,333 4%
Total	4,098,850	3,681,230 -11%	4,048,335 9%	4,174,020 3%	4,235,756 1%

¹ The statistics shown in the table are summed for the 44 States that reported total (non-zero) values for each year from 2008 to 2012. The issued permits were for travel both on and off Interstate highways. return to Table 1

Federal regulations regarding vehicle size place limits on the States’ ability to regulate truck size if the truck is defined as a STAA vehicle and is traveling on the National Network that includes the Interstate Highway System and sections of the Federal-aid Primary System. Congress authorized the National Network in the Surface Transportation Assistance Act of 1982 (P.L. 97-424) to guarantee mobility rights to trucks defined as STAA vehicles thereby protecting interstate commerce. A description of the National Network can be found in 23 CFR Part 658 Appendix A and is shown in Figure 1.

All States must allow STAA vehicles to operate on their highways; only 14 States and 6 turnpike authorities allow LCVs that weigh more than 80,000 lbs. on some parts of their road networks (Figure 2) (USDOT FHWA 2014). Since June 1, 1991, Congress has frozen the weights and dimensions of vehicles and the roadways on which LCVs can operate. States do not have the authority to remove restrictions related to the operation of LCVs, referred to as the ISTEA Freeze.⁸ In addition, 17 States allow triple-trailer combination trucks to operate on their roadways (Table 2). Most of these States are located in the Western United States.

Figure 1. National Network for Conventional Combination Trucks: 2013

Notes: The National Network was authorized by the Surface Transportation Assistance Act of 1982 (P.L. 97-424) and specified in the U.S. Code of Federal Regulations (23 CFR 658) to require that States allow conventional combinations on "the Interstate System and those portions of the Federal-aid Primary System serving to link principal cities and densely developed portions of the States on high volume routes utilized extensively by large vehicles for interstate commerce. Conventional combinations are tractors with one semitrailer up to 48 ft. in length or with one 28-ft. semitrailer and one 28-ft. trailer up to 102 inches wide. The National Truck Network (NN) differs in extent and purpose from the National Highway System (NHS), which was created more than a decade later by the National Highway System Designation Act of 1995 (P.L. 104-59) and modified in 2012 by the Moving Ahead for Progress in the 21st Century Act (P.L. 112-141). The NN was originally established in 1982 to protect interstate commerce by prohibiting restrictions on trucks of certain dimensions on a national network of roads, while the NHS supports long distance interstate travel such as connecting routes between principal metropolitan areas and industrial centers important to national defense and the national economy.

Figure 2. Permitted Longer Combination Vehicles on the NHS: 2011

As discussed above, larger and heavier trucks have been operating on our Nation’s highways for decades. This experience has provided an empirical basis upon which to analyze the impacts of increasing truck size and weight limits in the United States, as required by MAP-21.

Source: Title 23 Code of Federal Regulations, Part 658, Appendix C.

Other Countries’ Truck Size and Weight Regulations

The following discussion summarizes our North American neighbors’ approach to regulating truck size and weight, followed by a review of regulations in the European Union and Australia. Mexico and Canada are two of our country’s top trading partners, accounting for approximately $1.1 trillion in trade in 2012, or nearly 30 percent of the total value of United States trade. Trucks have carried about 60 percent of the value of goods traded with these two countries (USDOT FHWA 2014). Since NAFTA was established in 1994, the U.S. has not made major changes to its trucks size and weight regulations. Both Mexico and Canada have made several adjustments and have achieved substantial domestic harmonization (NCHRP 2010).

Mexico

Mexico has regulated commercial vehicle size and weight since the 1950s. Since then, the maximum allowable size and weight has changed several times. The Ministry of Communications and Transport establishes truck size and weight standards for the Federal highway system. States do not have authority to establish different standards from those promulgated by the Federal Government.

Standards are based on vehicle configuration (e.g., type and number of axles, wheels per axle, and suspension) and highway classification, of which there are five. Not all commercial vehicles can operate on all roadways. The highest category of roadways can accommodate vehicles with the maximum allowable capacity and size. LCVs, for example, are allowed only on the highest category of highways that have the geometric and structural characteristics to accommodate vehicles with maximum capacity and dimensions.

The 2008 revision to truck size and weight standards is the latest and is in use today; it should be noted that Mexico is currently examining its truck mass and dimension limits for trucks. In general, Mexico allows higher axle and gross vehicle weights than those allowed in the United States. Because of this, many Mexican trucks carrying goods to the United States must offload their cargo before crossing the border in order to comply with United States laws. Mexico’s size and weight regulations also include exemptions and special permits. Current commercial truck configurations range from vehicles with 3-axles/10 tires to 8-axles/30 tires. The typical five-axle combination vehicle operating in Mexico is similar in dimensions to the five-axle vehicles operating in the United States (NCHRP 2011).

Recently, Mexico has engaged the USDOT to seek technical assistance in its effort to evaluate current Mexican national truck size and weight limits and the network of roadways that certain trucks can operate on.

Canada

Canada has been a pioneer is using performance-based standards as a basis for developing commercial vehicle size and weight limits for inter-province operations. Through the Memorandum of Understanding (MOU) Respecting a Federal-Provincial-Territorial Agreement on Vehicle Weights and Dimensions, Canada has improved uniformity in truck size and weight regulations across its provinces and territories. Since its approval by all provinces and territories in 1988, the MOU has been amended six times in order to add truck configurations and to adjust standards. The latest amendment was added in 2009. Technical studies of truck dynamics and impacts conducted by provinces and the Federal Government provided the basis for the MOU (ITF/JTRC/OECD 2010). Recently, the Province of Ontario completed a study evaluating the operational feasibility of allowing 60-ft. semitrailers.

The current MOU establishes specifications for seven truck configurations and provides a list of roads that each province has identified. A vehicle that meets MOU configuration specifications can operate on roads identified in the MOU (provided all other regulatory conditions are met, such as an appropriate driver’s license and possession of a safety fitness certificate). Canada has higher weight limits than the United States for three types of trucks with six, seven, and eight axles (CMRTHS 2005).

European Union (EU)

Commercial vehicle size and weight limits are largely consistent among member countries for cross-border travel. Country-imposed limits for national travel vary but must not be lower than EU requirements except in cases where the infrastructure along secondary roads cannot support the load (USDOT FHWA 2007).

A 1996 EU directive defined length, width, and height limits for trucks and various other commercial vehicles traveling between EU member States (EC Directive 96/53/EC of July 25, 1996) for the purpose of facilitating trade and ensuring the free movement of goods in Europe. Noncompliant trucks registered before September 1997 are allowed to operate under a grandfather clause, but no new vehicles registered after 2006 were allowed to operate without meeting the length, width, and height requirements. Axle weight limits depend on axle spacing.

The EU is considering allowing longer and heavier vehicles (LHV), also known as mega-trucks and Eco-Liners, to transport goods across Europe. The proposed vehicles would measure 25.25 meters (82.84 ft.) in length and weigh 60 metric tonnes (132,277 lbs.), exceeding the size and weight of any commercial vehicle operating in the United States. Although LHVs have not been approved by many European countries, Sweden and Finland have permitted LHVs to operate on their roadways for more than 40 years, but they are not allowed to cross into other European countries. Other member countries, including the Netherlands, Denmark, and Germany are conducting trials that allow LHVs to operate on their national road network. In these cases, a special temporary permission is given, in line with EU legislation allowing for exemptions, and the vehicles can be operated under prescribed conditions on certain parts of the national road network (ITF/OECD/JTF 2010).

Currently, Directive 96/53/EC is under review by the EU with truck size and weight limits being evaluated. Broader international mobility privileges have been extended to LHVs in situations where two countries agree to allow their operation and the mass and dimension characteristics of the LHV do not exceed the limits in place in each of the countries. The LHV international mobility issue is under debate as part of the EU’s initiative to evaluate and update 96/53/EC.

The EU does not actively monitor the application of directives. After implementation, member countries are required to enforce the directives. Moreover, there are no reporting requirements on day-to-day operations. Usually, the European Union is notified of a problem through a complaint process. After a complaint is received, the EU notifies the member country, requests an explanation, and initiates a judicial procedure, if appropriate, through the EU Court of Justice (USDOT FHWA 2007).

Australia

Although state and territorial governments control the size and weights of heavy vehicles, there is a high degree of uniformity in commercial vehicle size and weight regulations, especially for trucks with a GVW of up to and around 46 metric tonne (101,412 lbs.). GVW and vehicle length vary by truck configuration.

Australia, like Canada, uses a performance-based approach to regulate size and weight. This approach considers safety and environmental objectives but does not prescribe how to achieve those objectives. Performance-based standards (PBS) are applied in the custom construction of certain trailers designed to accommodate a specific load movement and are more stringent in high-risk areas (high populations) than in low-risk areas such as the State of Western Australia also commonly known as the “Outback.” The PBS program in Australia has been in operation since the mid-2000s and has recently transitioned from operating under a single, national regulator scheme to a State- and Territory-based regulatory framework.

The largest trucks in the world are found in Australia. The State of Victoria, Australia, began testing trucks with a length limit of 30 meters (98 ft.) and a load limit of 77.5 metric tonnes (170,858 lbs.) in 2009 (ITF/JTRC/OECD 2010). More recently, a pilot was conducted in Victoria to evaluate the safety implications of operating B-Train triples ⁹ in urban areas. Until now, the B-train triples were restricted to rural motorway segments under the Australian Intelligent Access Program.

Australia is a leader in using technologies to actively monitor compliance with allowances extended through a special permit. Special devices must be plugged into the vehicle’s CAN-BUS (a digital communications network) to emit signals to the regulating body. Adherence to weight and dimension allowances and the approved route for the load movement is monitored remotely by the regulating body with intervention by enforcement personnel in cases where non-compliance with the terms of the special permit is observed. Australia views the issuance of a special permit to operate above weight and dimension limits as a privilege and routinely requires concessions from the transporter as a condition for receiving the special permit.

References

Canadian Council of Ministers Responsible for Transportation and Highway Safety (CMRTHS), Task Force on Vehicle Weights and Dimensions Policy. 2005. Heavy Truck Weight and Dimension Limits for Interprovincial Operations in Canada, Summary Information, August, 2014. Available at www.comt.ca/english/programs/trucking/MOU%202011.pdf as of May 15, 2014.

International Transport Forum (ITF), Joint Transport Research Centre of the Organization for Economic Co-operation and Development (JTRC/OECD). 2010. Moving Freight with Better Trucks, Final Report. Available at www.internationatransportforum.org/jtrc/infrastructure/heavyveh/TrucksSum.pdf as of May 13, 2014.

National Cooperative Highway Research Program (NCHRP). 2011. Review of Mexican Experience with the Regulation of Large Commercial Motor Vehicles, Research Results Digest 362. October. Available at http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rrd_362.pdf as of May 16, 2014.

National Cooperative Highway Research Program (NCHRP). 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles, Report 671. Washington, DC: National Academy of Sciences. Available at http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_671.pdf as of May 15, 2014.

U.S. Department of Transportation (USDOT), Federal Highway Administration (FHWA). 2014a. Freight Facts and Figures 2013. January. Available at www.ops.fhwa.dot.gov/freight/freight_analysis as of May 14, 2014.

U.S. Department of Transportation (USDOT), Federal Highway Administration (FHWA). 2014b. Highway Statistics 2012. January. Available at www.fhwa.dot.gov/policyinformation/statistics/2012/vm1.cfm.

U.S. Department of Transportation (USDOT), Federal Highway Administration (FHWA). 2007. Commercial Motor Vehicle Size and Weight Enforcement in Europe, FHWA-PL-07-002. March. Available at www.fhwa.dot.gov/pubs/pl07002/.

Department of Transportation (USDOT), Federal Highway Administration (FHWA). 2004. Federal Size Regulations for Commercial Motor Vehicles. October. FHWA-HOP-04-022. Available at www.ops.fhwa.dot.gov/freight as of May 15, 2014.

U.S. Library of Congress (USLOC), Congressional Research Service (CRS). 2014. Status of Mexican Trucks in the U.S.: Frequently Asked Questions by John Frittelli, CRS Report R41821. January 3. Available at www.crs.gov as of May 20, 2014.

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