Truck Weight Regulations Research Articles

Perceptions of Log Truck Weight Regulations Among Loggers and Forest Industry in Georgia, USA

Abstract Georgia and other southern states have far lower gross vehicle weight (GVW) limits for log trucks than other US regions and other countries. Low GVW limits result in high hauling costs and truck traffic. In 2020, including tolerances, five-axle log tractor-trailers were allowed 38,102 kg (84,000 lb) GVW in Georgia. Telephone surveys of 30 loggers and 32 forest industry representatives from the state of Georgia were conducted to measure perceptions of weight regulations and assess support for alternative weights and configurations. The four alternatives included five axles, 39,916 kg (88,000 lb); six axles, 41,277 kg (91,000 lb); six axles, 45,359 kg (100,000 lb); and seven axles, 45,359 kg (100,000 lb) GVW. The majority of loggers and forest industry representatives stated that GVW limits for log trucks were too low. The average preferred GVW limits were 39,621 kg (87,350 lb) and 40,545 kg (89,387 lb) for loggers and forest industry, respectively. Loggers and forest industry supported the five-axle 39,916 kg (88,000 lb) configuration whereas many loggers opposed both 45,359 kg (100,000 lb) configurations. Loggers, forest industry, and policymakers should work to modernize weight laws to reduce hauling costs, maintain or improve safety, and protect public infrastructure.

Evolution of bridge live load models and truck weight limits: the case of Manitoba, Canada

Changes in the size and weight regulations for trucks have been used to improve their productivity, safety, and operational performance in Canada. In response to these changes, bridge design codes undergo modifications to envelop the potential range of trucks in operation. A five-decade timeline is presented to: (i) document how bridge codes and their live load models have evolved, with a focus on the Manitoba-specific HSS-25 truck; and (ii) discuss how responsive the bridge design codes have historically been to changes in truck size and weight regulations. While at times bridge codes are released in conjunction with expected regulation changes, there is often delay in the issuance of those codes. Assessments of the current truck fleet, which now includes long combination vehicles (LCVs), may be a consideration for future bridge live load models.

Reliability-Based Truck Weight Regulation of Small- to Medium-Span Bridges

Reliability-Based Truck Weight Regulation of Small- to Medium-Span Bridges

Opportunity Cost for Society Related to U.S. Truck Size and Weight Regulation: Freight Efficiency

Improvements in truck freight efficiency through such measures as optimized logistics and truck loading, the utilization of other transportation modes, and the reform of federal truck size and weight policy are expected to require fewer truck trips to move the nation’s freight. This reduction in truck travel distance should bring with it reductions in fuel consumption, emissions, and casualties as a result of reduced exposure. This paper discusses truck size and weight policy domestically and internationally and contrasts U.S. mass efficiency with that of the country’s North American Free Trade Agreement partners and, more broadly, with countries outside of North America. The analysis reveals the outdated nature of U.S. federal size and weight policy compared with other nations. The inability of U.S. federal policy to remain current with other countries is a result of a freeze on policy change that has been in place since 1982. An analysis of the societal benefits associated with improvements in truck freight efficiency is provided. Rather than estimating the precise benefits associated with the many options available, the analysis examines the benefits associated with a 10% reduction in truck travel distance. In this way, the paper provides insight into the significance of improved freight efficiency that reduces total truck travel distance, which in turn provides fuel savings, a reduction in emissions, and a reduction in truck crash frequency. The analysis concludes that a 10% reduction in truck distance traveled for a fixed national freight task would generate approximately $16 billion, save 330 lives, and prevent approximately 4,000 injuries per year.

Evaluating sustainability of truck weight regulations: A system dynamics view

Purpose: Targeting the problem of overload trucking in Highway Transportation of iron ore from Caofeidian to Tangshan (HTCT), this paper aims to assess long-term effects of alternative Truck Weight Regulation (TWR) policies on sustainability of HTCT. Design/methodology/approach: A system dynamics model was established for policy evaluation. The model, composed of six interrelating modules, is able to simulate policies effects on trucking issues such as freight flow, truck traffic flow, pavement performance, highway transport capacity and trucking time, and further on the Cumulative Economic Cost (CEC) including transport cost and time cost of freight owners and the Cumulative Social Cost (CSC) including pavement maintenance cost, green house gas emission cost, air pollutants emission cost and traffic accidents cost, so the effects of TWR policies on sustainability of HTCT could be evaluated. Findings: According to different values of overload ratio which a TWR policy allows, alternative TWR policies are classified into three types, which are The Rigid Policy (TRP), The Moderate Policy (TMP) and The Tolerant Policy (TTP). Results show that the best policy for sustainability of HTCT depends on the importance of CSC which is expected by the local government. To be specific, (1) if CSC is considered much less important than CEC, the local government should continue implementing the current TTP with the maximum overload ratio; (2) if CSC is considered much more important than CEC, then TRP is recommended; and (3) if CSC is considered slightly more important than CES, TMP with overload ratio of 80% is the best. Practical implications: Conclusions of this paper may help the local government design appropriate TWR policies to achieve sustainability of HTCT. Originality/value: To the best of our knowledge, this is the first effort to evaluate TWR policies on sustainability of regional freight transportation based on system dynamics modeling.

Existing Bridge Formulas for Truck-Weight Regulation from International Jurisdictions and Resulting Load Stresses on Single-Span Bridges

AbstractThis paper identifies and characterizes existing bridge formulas from international regions and presents the results of an analysis of the allowable gross vehicle weights and bridge load stress effects on single-span bridges resulting from these formulas. This is done to provide insight into this method of regulating truck size and weight to identify influencing factors and considerations for future decisions regarding the creation of new bridge formulas, or modification of existing ones. It is found that bridge formulas vary significantly in terms of the level of restrictiveness of allowable loads and imposed load effects due to the design criteria used in their development including truck configurations, bridge design methods, design loads, and allowable load rating. Bridge formulas should be designed to limit the imposed stresses on bridges based on criteria suitable to a jurisdiction’s truck fleet and infrastructure characteristics in order to adequately regulate truck sizes and weights. Many ...

Truck Body Configuration Volume and Weight Distribution

Weigh-in-motion (WIM) systems measure truck volumes, assist in pavement design and management, and enforce truck size and weight regulations. Although WIM systems provide truck classification based on the FHWA axle configuration classification scheme, more specific vehicle characteristics such as body configuration are necessary for freight planning and pollution monitoring. A modified decision tree model was developed to estimate truck volumes and gross vehicle weight (GVW) distributions by body configuration for five-axle semi-tractor trailers (3S2) with the use of existing WIM system measurements such as axle spacing and vehicle length. This method allows more information to be extracted from axle-based measurement data to leverage the significant investments in existing WIM systems better. Data for model development were collected at three WIM sites spanning rural and urban locations in California and described more than 7,500 3S2 trucks stratified into five trailer body categories: vans, tanks, platforms, 40-ft intermodal containers, and other. Model estimates of trailer body configuration volumes differ by only 8% from actual volumes when averaged across all body configurations on an independent test data set. A normalization procedure was designed to improve the model's robustness against systematic and random calibration inaccuracies at WIM sites. An algorithm based on Gaussian mixture models was developed to estimate GVW distribution by body configuration. Results show that estimated GVW distributions statistically capture the actual GVW distribution of each body configuration and are temporally and spatially transferable.

Analysis of Imposed Bridge Load Stresses for Development of a European Bridge Formula

This paper evaluates the characteristics of international bridge formulas developed and implemented by different countries and analyzes the imposed bridge load effects resulting from trucks complying with international bridge formula–allowable loads and truck size and weight regulations in Europe. This evaluation was done to identify issues that may need to be considered in the development of a European bridge formula for the regulation of truck size and weight limits associated with international travel between European Union member states. Differences in national weight limits in European Union countries and the increasing demand for larger and heavier vehicles bring about the need to ensure the structural integrity and service life of bridges. Bridge formulas provide a method for regulating truck weights while ensuring the sustainability of infrastructure by allowing vehicle configurations that have an acceptable load effect on structures. This method allows for long-term truck size and weight evolutions for productivity gains while preserving the existing stock of bridges. The level of efficiency of a bridge formula varies depending on the design criteria used in the development of the formula, the compatibility of the jurisdiction's infrastructure and truck fleet characteristics, and the method of implementation as part of the regulation and by operators in the trucking industry. This research can help guide the development of a European bridge formula and contributes new knowledge for countries that currently apply a bridge formula to regulate truck weights.

Practices of using weigh-in-motion technology for truck weight regulation in China

Trucks exceeding legal axle and gross vehicle weight limits can bring severe damage to infrastructure and increase the risk of traffic crashes. It is therefore important to ensure that freight carriers comply with weight regulations. This paper provides a comprehensive review of how weigh-in-motion (WIM) technology has been used to improve the truck weight regulation in China. In particular, a toll-by-weight method is introduced for trucks using toll roads. Compared to the conventional vehicle class based toll structure, the toll-by-weight method establishes a fair fee structure that prevents overloaded trucks from taking advantage of non-overloaded trucks. It also allows freight carriers the flexibility of moderate overloading by paying higher toll rates. This paper further proposes a mechanism of integrating toll-by-weight with effective weight enforcement for truck weight regulations. It encourages overloaded trucks to use toll roads instead of vulnerable non-toll roads, and helps to generate additional much needed revenues by local governments for highway construction, maintenance, and truck weight enforcement. In addition, technical and managerial problems affecting the applications of WIM are pointed out in this paper. Finally, perspectives on future WIM development and adaptions of other advanced technologies for truck weight regulations are presented.

Options for Hauling Fully Loaded ISO Containers in the United States

AbstractCivil engineers plan, design, manage, and guide investments in surface transportation. Truck weight limits are inextricably linked to the consideration of pavements, bridges, safety, asset management, sustainability, jobs, and economic productivity. The U.S. 36.3 t cap for gross vehicle weight (GVW), and the Federal Bridge Formula B (FBF B) constrain truck movement of 32.5 t full ISO (International Organization for Standardization) containers. This study identifies the options—and associated implications—for trucks to transport full containers notwithstanding FBF B and the cap. We conducted a national investigation of truck weight regulations across 50 states to identify options, with 28 cases involving telephone interviews. Results show the options are complex, vary by state, result in a patchwork of routes, and include: (1) nondivisible permits, (2) special haul routes, (3) grandfather rights, (4) state roads, (5) tare reduction, and (6) operation outside formal regulations. Containerships, rail...

Economic Benefit of Maximum Truck Weight Regulation Change for Estonian Forest Sector

Current paper is focused on analyzing the economic benefit of increasing maximum allowed truck weight for Estonian forest sector. It is producing economic benefits to the firms of forest sector in two broad areas. The change in truck weight limit regulation is causing the reduction of transportation costs for forest sector firms.Increase of the truck weight limit from current 44 up to 60 tonnes is going to reduce the share of transportation costs in roundwood material prices from 17.7% to 14.2%.Secondly, the growth of demand for roundwood as the result of decreasing transportation costs was determined. Using own and cross elasticities between road and rail transportation, the apparent domestic consumption is expected to grow in the range from 0.7-4.6 % depending on the change of regulation from 44 to 60 tonnes, whereas in the most probable situation (change from 52 to 60 tonnes) the growth in apparent domestic consumption is 0.3-1.1%.

Application of system dynamics for evaluating truck weight regulations

In the situation of prevailing overweight transportation and difficult enforcement in China, this paper develops a methodological framework for truck weight regulation evaluation using System Dynamics. Composed of five interrelated subsystems, the framework is able to capture the highway, vehicle and freight variables that influence the effect of TWR and transportation efficiency over time. It specifically describes the development and use of the Truck Weight Regulation Evaluating Model for the highway freight system in Anhui province, China. The simulation results show that, among three policy alternatives, the moderate policy approach is the most appropriate option to solve the social and economic problems arising from overweight transportation in Anhui. In addition, some suggestions of TWR policy in China are also made in this paper.

Options for Exposure-Based Charging for Long Multiple Trailer Truck Permits

This paper analyzes options for exposure-based charging for long multiple trailer truck permits. Long trucks—Rocky Mountain doubles, turnpike doubles, and triple trailer combinations—are granted permits because they provide increased technical productivity for hauling low-density freight. Experiences in the Canadian Prairie Region indicate that standardization of rationales used to establish permit charges is increasingly important as the network permitting long trucks expands and enables regional operation. Contributing to the differences in charging perspectives is the cube-out condition under which most long trucks operate, which challenges the justification for assessing incremental fees for their operation. An analysis of truck size and weight regulations governing the cubic trucking domain demonstrates that trucks in this domain are ideally suited for freight densities up to about 240 kg/m3 (15 lb/ft3). Four exposure-based options for establishing permit charges are presented: revenue-based charging, cost recovery, incentive provision, and privatization. Carrier costs and public revenues for three cases in the revenue-based charging option—benefit-sharing, revenue neutrality, and full benefit taxation—are analyzed and compared with the current base case conditions in Manitoba. The analysis reveals increases in turnpike double operating costs ranging from 2% for revenue neutrality to 50% for full benefit taxation. Corresponding public revenue increases for these three cases range from 30% for revenue neutrality to a 12-fold increase for full benefit taxation. The sensitivity of the results to freight density and utilization demonstrates the need for charges to reflect differences between cube-out and weigh-out conditions, and the distance traveled by long trucks.

Analyzing Effects of Spring Highway Load Restrictions on North Dakota's Agricultural Freight Flows

This paper describes a statewide agricultural freight transportation model that is used to estimate the benefits of improving North Dakota's state highway system by removing spring load restrictions. The transportation model measures changes in freight flows caused by truck weight regulations during the spring thaw cycle. The primary focus is on grain transportation. A geographic information system (GIS) network of federal, state, and county roads is developed to represent flows from fields to elevators and final destinations. The state is divided into 182 production zones on the basis of agricultural land use patterns. The data for the trip generation component of the model are derived from satellite imagery of crop layers in the state, with the use of GIS spatial analysis and algorithms developed for this purpose. The annual demand at elevators is estimated from grain movement reports filed with the State of North Dakota. Agricultural freight movement is modeled separately as two flows: internal-to-internal (i.e., from fields to elevators) and internal-to-external (i.e., from elevators to final destinations). CUBE transportation planning software is used to model the flows. In addition, the onion model concept used in Iowa is applied as a demand planning tool to capture the effects of spring load restrictions, which are dynamic and move from the southern to the northern part of the state during the spring thaw cycle. The costs of spring load limits are quantified as the increased distance and travel time caused by circuitous truck movements or as the reduced payload per trip.

Performance-Based Design of an Innovative Truck-Trailer Configuration

This paper describes the process whereby one of Australia's major fuel distributors recently gained approval to operate an innovative truck-trailer configuration that was needed to overcome some prescriptive truck size and weight limits and to satisfy the company's new policy on the improvement of fleet safety. Using Australia's newly developed performance-based standards for truck size and weight regulation as the design driver, the process began with field testing of the company's safest existing vehicles, went on to the iterative design of an improved concept by vehicle dynamics simulation, and ended with field testing and calibrated computer simulation of a prototype vehicle for certification. While demonstrating a quantum improvement in dynamic stability, the concept also offers a substantial increase in payload capacity. The process was a valuable learning experience for Australia's truck size and weight regulators and performance-based standards practitioners and is expected to pave the way for continued innovation by this company and others.

Performance-Based Design of an Innovative Truck-Trailer Configuration: Safer and More Efficient Distribution of Liquid Fuel in Australia

This paper describes the process whereby one of Australia's major fuel distributors recently gained approval to operate an innovative truck-trailer configuration that was needed to overcome some prescriptive truck size and weight limits and to satisfy the company's new policy on the improvement of fleet safety. Using Australia's newly developed performance-based standards for truck size and weight regulation as the design driver, the process began with field testing of the company's safest existing vehicles, went on to the iterative design of an improved concept by vehicle dynamics simulation, and ended with field testing and calibrated computer simulation of a prototype vehicle for certification. While demonstrating a quantum improvement in dynamic stability, the concept also offers a substantial increase in payload capacity. The process was a valuable learning experience for Australia's truck size and weight regulators and performance-based standards practitioners and is expected to pave the way for con...

Trucking Efficiency Versus Transportation Efficiency: An Economic Evaluation of TRB Special Report 267

TRB Special Report 267: Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles is critically evaluated. It is an important, congressionally mandated report that contains a series of conclusions and recommendations regarding truck size and weight (TS&W) regulations in the United States. The report concludes that increases in TS&W limits have great potential for increasing freight market efficiency but that safety and other effects are not well understood. To facilitate the liberalization of TS&W limits, the report recommends a revised regulatory regime that would involve federal supervision of state-set limits, with evaluation provided by an independent Commercial Traffic Effects Institute. This evaluation argues that the report focuses too narrowly on trucking efficiency and overlooks transportation efficiency. This narrow analytical perspective significantly limits its usefulness in establishing national transportation policy. Also, there is no analytical basis for the report's most important conclusions and recommendations, either in the report or in earlier TS&W studies evaluated by the Committee for the Study of the Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles.

Seasonal weight limits on prairie region highways: opportunities for rationalization and harmonization

There are a myriad of laws, regulations, and policies governing the operating weights and dimensions of trucks. In Canada and many northern states, these regulations form a continuum of basic limits, seasonal variations, and overweight/overdimension limits that are legally permitted. This paper deals with the seasonal aspects of weight limits (winter weight premiums and spring weight restrictions) governing trucking within and to and from the prairie region. This region encompasses Manitoba, Saskatchewan, and Alberta, and the northern tier states of Minnesota, North Dakota, and Montana. The paper presents results of research conducted for the transportation departments of the three prairie provinces and Public Works and Government Services Canada. It discusses existing winter weight premium and spring weight restriction regulations, as well as basic weight regulations in the region, and their technical rationale. It examines possibilities for using advanced technologies to help harmonize and rationalize seasonal truck size and weight regulations and enforcement practices, and identifies immediate opportunities for rationalization and harmonization of spring weight restrictions and winter weight premiums.Key words: trucking, weight regulations, spring restrictions, winter premiums, prairie region, harmonization, rationalization.

Effect of Changing Truck Weight Regulations on U.S. Bridge Network

Historically, truck weight regulations have maintained controls on axle and gross weights with legal load formulas based on limiting allowable stresses in certain types of bridges. These stress limitations do not usually lead to consistent or defensible reliability levels and also ignore the impact of the weight regulation on the existing highway bridge network. This paper is the second part of a two-paper series. The companion paper by the first writer illustrated how new truck weight regulations can be developed to provide an acceptable reliability level. The target reliability level was derived from bridge structures designed to satisfy AASHTO standard design specifications that showed safe and adequate performance levels under current truck loading conditions. In this part of the two-paper series, a deterministric load capacity evaluation as well as a reliability assessment are performed to review the consequences of adapting such regulations on the existing U.S. bridge network. A sensitivity analysis shows how changes in the safety criteria used to develop the truck weight regulations would affect the existing bridge network. Detailed load capacity evaluations and reliability analyses are also performed on a representative sample of bridges to provide specific examples of expected changes in rating and safety levels if the proposed truck weight regulation is to be adopted.

Development of Truck Weight Regulations Using Bridge Reliability Model

Historically, truck regulations have maintained controls on axle and gross weights with legal load formulas based on limiting allowable stresses in certain types of bridges. These stress limitations do not usually lead to consistent or defensible safety levels and also ignore the cost impact of the weight regulation on the national bridge network. This paper illustrates how new truck weight regulations can be developed to provide acceptable safety levels. Target safety levels are derived from existing AASHTO bridge evaluation and rating procedures applied to structures showing adequate performance levels. Reliability indices are used to relate the statistics of bridge load effects, based on either existing or proposed truck weight regulations, to the dynamic behavior and resistance variables of existing bridges. The sensitivity of the results to various assumptions and errors in the database is also analyzed. An accompanying paper reviews the consequences of adapting such a formula on the safety of existing bridges. The deterministic analysis as well as a reliability assessment are performed in the accompanying paper to review the consequences of adapting such regulations on the U.S. bridge network using the National Bridge Inventory files.