Overweight Vehicles Research Articles

Evaluation of Texas Superheavy-Load Criteria for Bridges

AbstractThe number of permits for superheavy loads crossing Texas bridges has steadily increased over the years, and compared with several other states, the criteria that establish superheavy-load status are generous. The result is that many Texas bridges experience high-stress loads that cause accelerated deterioration. In this study, bridge load and rating factors and the validity of the criteria for establishing superheavy-load status are evaluated. The primary objective of this study was to evaluate Texas superheavy-load criteria for bridges. To accomplish this, field tests for the response behavior of a bridge subjected to overweight vehicles and a parametric study using finite element analysis were utilized to extract bridge criteria triggers. The field-verified solid model and related parametric study show that the Texas superheavy-load criteria are valid for the study bridge type. Load ratings computed using the distribution factors determined in this study show that the evaluated bridge has much ...

Procedure for Statistical Categorization of Overweight Vehicles in a WIM Database

Recently observed increases in the numbers of permitted and illegal overweight trucks travelling over U.S. highways have raised concerns over their contributions to the reduction in the service lives of pavements and bridges and the costs of maintaining, upgrading and replacing the highway infrastructure system. Cost allocation studies are used by transportation officials to help their asset management processes and to establish truck traffic and permitting policies taking into consideration information on the composition of overweight trucks and their permit categorization. In recent years, cost allocation studies have heavily relied on data assembled by weigh-in-motion (WIM) systems which provide information on traffic counts, truck axle configurations and weights for various highway classes and economic regions. However, WIM data by themselves do not provide information on the numbers of illegal overweight trucks because many of the overweight trucks may have been issued permits that allow them to operate on a yearly basis or on a trip-by-trip basis. The object of this paper is to develop a data mining procedure to identify and classify overweight vehicles whose axle weights were collected by WIM systems into different permit and illegal categories. The first step of the proposed data mining procedure establishes a set of rules that are satisfied by different types of permit trucks. These rules are inferred from a review of available permit databases. In a second step, a search algorithm is used to check each vehicle in a WIM database and identify whether it violates any of a jurisdiction’s legal weight limits. Subsequently, every overweight truck’s axle weights, axle spacings, total length and gross vehicle weight are checked to verify whether these characteristics match any of the criteria established when setting up the data mining rules. The overweight vehicles are separated based on the likelihood of having been issued a particular type of permit or if they are potentially illegal. The validity of the algorithm is demonstrated by analyzing truck data collected at a WIM site in upstate New York. The algorithm’s output showed reasonable agreement when compared to the results of a truck survey performed by the New York State Department of Transportation (NYSDOT). A parametric analysis is executed to assess the sensitivity of the results to the level of accuracy of the WIM system. It is concluded that the algorithm produces statistically robust overweight truck and permit categorizations which can eventually help highway agencies establish rational permit issuance policies, weight enforcement strategies, and cost allocation studies.

Framework for Determining Load Equivalencies with DARWin-ME

This paper presents a methodology for use of mechanistic–empirical design procedures to determine load equivalencies for various axle configurations and loads with a focus on oversize and overweight vehicles. The study uses the DARWin-ME system for pavement analysis and computation of equivalent damage factors (EDFs). In the context of the study, the EDFs for a given axle load and configuration consist of two partial factors: the axle load factor and the group equivalency factor. The framework adopted in this study defines a given axle load and configuration equivalent to a reference axle load based on equivalent pavement responses that results in the same distress level. The EDFs for single, tandem, tridem, and quad axles were evaluated for a wide spectrum of varying loads, and three failure criteria were applied: rutting, fatigue cracking, and roughness. Except in the case of rutting, there was no evidence that EDFs are affected by the structural capacity of the pavement sections. For single axles, it was found that thicker pavement structures are less sensitive to traffic loads. For tandem, tridem, and quad axles, the relationship was nonmonotonic. For fatigue cracking, a linear relationship between the axle load factor and the number of axles per axle group was observed. Finally, for roughness, the EDFs showed no systematic trend for the different structural numbers.

고속축중기를 활용한 과적단속시스템의 과적 억제효과 분석

PURPOSES: The aim of this study is to analyze overloading control effectiveness of enforcing overweighted vehicles using HS-WIM (High-Speed Weigh-in-Motion) at main lane of expressway. METHODS: To analyze the weight distribution statistically, HS-WIM system should has an appropriate weighing accuracy. Thus, the weighing accuracy of the two HS-WIM systems was estimated by applying European specifications and ASTM (American Standards for Testing and Materials) for WIM in this study. Based on the results of accuracy test, overweight enforcement system has been operated at main lanes of two expressway routes in order to provide weight informations of overweighted vehicle in real time for enforcement squad. To evaluate the overloading control effectiveness with enforcement, traffic volume and axle loads of trucks for two months at the right after beginning of the enforcement were compared with data set for same periods before the enforcement. RESULTS: As the results of weighing accuracy test, both WIM systems were accepted to the most precise type that can be useful to applicate not only statistical purpose but enforcing on overweight vehicles directly. After the enforcement, the rate of overweighted trucks that weighed over enforcement limits had been decreased by 27% compared with the rate before the enforcement. Especially, the rate of overweighted trucks that weighed over 48 tons had been decreased by 91%. On the other hand, in counterpoint to decrease of the overweighted vehicle, the rate of trucks that weighed under enforcement limits had been increased by 7%. CONCLUSIONS: From the results, it is quite clear that overloading has been controlled since the beginning of the enforcement.

Design of a real-time overload monitoring system for bridges and roads based on structural response

The problem of the general overload of vehicles that causing premature failure of bridges and roads is becoming more and more obvious. Structural behaviors of bridges and roads need real-time monitoring and diagnosis, timely damage detection, safety evaluation and necessary precautions, in order to prevent accidents such as the crack or the collapse of bridges and roads. However, the existing monitoring system is too expensive to be applied in low budget projects. This paper designs a portable, low-cost, low-power structural monitoring system, which is equipped with Polyvinylidene Fluoride (PVDF) traffic sensors, a central processing unit (CPU), an amplifier circuit, an Analog/Digital (A/D) converter circuit, a communication circuit, an alarm circuit, and analysis software. The proposed system can collect the critical data for a certain judge algorithm about the force of the pavement. An alarm will be signaled and the overweight data will be transmitted to the data center to make further analysis. At the same time, the license plate numbers of the overweight vehicles will be collected and sent to the traffic management department. The system has been tested and the results are satisfactory. Because of its features of simple structure, easy implementation, and low cost, the proposed system fills the application gaps of structural health monitoring in low-budget projects.

Indonesia: Telling Lies

Indonesia: Telling Lies

The Application of FBG-Based Overweight Vehicle Recognition for Existing Bridge

In order to know the operation condition of bridges when they’re under the action of overweight vehicles, it’s necessary to collect the testing information of bridges under the overloaded condition. Based on the high-speed demodulation instrument, the optical fiber grating (FBG) sensor system can realize the continuous collection for the dynamic strain of structure. According to the analysis of the collected data, auto-sorting and recognition for overweight vehicles can be realized. The introductive system has been applied to the health monitoring system of no.2 Wuhan Bridge over Yangtze River (N2WB). The result showed that not only it’s able to recognize whether or not there was an overweight vehicle passing the bridge, but also it could auto-sort the grade of overweight vehicles, which was an effective overweight vehicle monitoring tool for the existing large span bridges.

Index for Estimating Road Vulnerability to Damage from Overweight Vehicles

One component of North Carolina's motor carrier enforcement program is focused on overweight trucks. The aim of this enforcement program is to protect the state's roadway infrastructure, and as such it is important to identify those facilities and roadway segments that are most susceptible to damage from overweight vehicles. For that purpose, a quantitative road vulnerability index (RVI) was developed. Vulnerability is expressed as a function of truck volume, pavement condition, and bridge condition. By weighting these factors, one can assign vulnerability values to road segments statewide. Vulnerable road segments are then mapped in the same geographic information system (GIS) environment used to capture and display motor carrier enforcement activities for overweight violations. In addition to providing information to aid in the spatial assignment of weight enforcement activities, the RVI uses GIS data as a useful tool for the visual analysis and integration of roadway maintenance and operations concerns across various divisions of the North Carolina Department of Transportation.

Lose Some, Save Some: Obesity, Automobile Demand, and Gasoline Consumption in the U.S.

This paper examines the unexplored link between the prevalence of overweight and obesity and vehicle demand in the United States. Exploring annual sales data of new passenger vehicles at the model level in 48 U.S. counties from 1999 to 2005, we find that new vehicles demanded by consumers are less fuel-efficient on average as a larger share of people becomes overweight or obese. The OLS results show that a 10 percentage point increase in obesity and overweight reduces the average MPG of new vehicles demanded by 1.4 percent, an effect requiring a 12 cent increase in gasoline prices to counteract. The 2SLS results after controlling for possible endogeneity in overweight and obesity prevalence put those two numbers at 5 percent and 54 cents, respectively. These findings, robust to a variety of specifications, suggest that policies to reduce overweight and obesity can have additional benefits for energy security and the environment.

Routing and Permitting Techniques of Overweight Vehicles

Overweight vehicles require permits to cross the highway bridges, which are designed for “design load vehicles” (prescribed in the national standards). A new, fast, and robust method is presented for the verification of bridges, which requires minimal input only: the axle loads, axle spacing, the bridge span(s), and the superstructure type. The bridge can be a single or a multispan girder, an arch bridge, a frame structure, or a box girder. The overweight vehicle may operate within regular traffic or it may cross the bridge at a given lane position while other traffic is prohibited on the bridge. The method is illustrated by numerical examples for deck-girder bridges and for a box girder.

Deterioration Analysis of Flexible Pavements under Overweight Vehicles

In this paper, the influence of overloading on the operational life of flexible pavements is discussed, leading to the development of a deterioration model for pavement and a ticketing formulation for overweight vehicles. To conduct this research, a theoretical model is developed for flexible pavements. Using this model, sensitivity analyses are made and the significant parameters that influence the deterioration of pavement under truck loading are investigated. The relationships between the passing loads and the number of allowable load cycles are obtained. These relationships form the basis for further models by which the damage ratios of flexible pavements are assessed and vehicle fines determined. A numerical example is presented to indicate the applicability and practicality of the proposed models.

Approximate Analysis of Bridges for the Routing and Permitting Procedures of Overweight Vehicles

The paper presents a method for comparing the mechanical effects of overweight and design load vehicles on bridges. There is no restriction on the arrangement of the axles and on the size of the axle loads. The bridge may be a simple span bridge, a continuous girder, a truss girder, or an arch. Even for a very complex bridge structure the only required parameter of the bridge is the span length. The presented method is a robust and reliable tool for the permitting process of overweight vehicles, which is verified by several thousand comparisons.

An overweight permit analysis system for bridge management

With the increased overweight traffic and freight transport due to the industrial growth, the risk of accidents has increased accordingly. Under such circumstances, the Seoul Metropolitan Government (SMG) has faced with the impending need to develop solutions associated with the traffic permit for commercial vehicles with oversized/overweight. Therefore, a practical and reli ability-based Overweight PERmit Analysis System (OPERAS) was developed in this paper due to this issuance for the SMG. The procedure taken for the development of the system includes data survey, structural analysis and load carrying capacity evaluation, and sa fety assessment of bridge structures on permit routes for the overweight vehicles. Also, optimum routes for overweight vehicles were selected among a number of road routes of Seoul. The modified Load and Resistance Factor Rating (LRFR) approach based on the AASHTO method for permit vehicles was utilized to evaluate the bridge load rating for permit vehicle. Load factors of permit vehicle for bridge LRFR evaluation were calibrated based on the reliability-based Moses’ model with Korean Standard rating load Single and multiple trips for permit vehicle can be evaluated using the developed system. The system automatically uptates the permit analysis results for bridges on routes according to the structural and traffic condition.

A web-based spatial decision support system optimizes routes for oversize/overweight vehicles in Delaware

Delaware Department of Transportation has developed a web-based spatial decision support system for managing the movement of oversize and overweight vehicles over the State's highways. This system combines network optimization techniques and a J2EE web-architecture to provide a robust, high-performance and scalable system meeting Delaware's current and future permit processing needs. The new system replaces existing manual processes, providing a number of immediate and future benefits including reducing time to calculate some permits from weeks to seconds, reducing processing costs and providing potential safety benefits by reacting to rapidly changing highway conditions.

Nondestructive Evaluation of the I-40 Bridge over the Rio Grande River

A nondestructive strength evaluation of the I-40 Bridge over the Rio Grande River in Albuquerque, N.M. was completed for the New Mexico Department of Transportation (NMDOT). The I-40 Bridge is a precast, prestressed concrete girder bridge located within 3mi. of the “Big I” interchange carrying Interstates I-40 and I-25. Because of its location, the I-40 Bridge is subjected to large amounts of heavy truck traffic. The primary objective of the study reported herein was to determine a more accurate capacity rating for the I-40 Bridge and thus, reduce the number of overweight vehicle permit denials. To achieve this objective, a conventional rating analysis is first performed based on American Association of State Highway and Transportation Officials (AASHTO) guidelines. A diagnostic load test and a finite-element analysis are then completed. Details of the AASHTO rating analysis as well as the approach by which measured girder strains from the load test and finite-element results were considered in the capacity rating of the I-40 Bridge are discussed. Findings from the study confirmed that the capacity ratings of the I-40 Bridge could be safely increased by a factor of 1.7.

Preservation of Infrastructure by Using Weigh-in-Motion Coordinated Weight Enforcement

The Montana Department of Transportation (DOT) has completed a pilot project in which data from a statewide network of weigh-in-motion (WIM) sensors were used to assist in scheduling weight-enforcement activities of patrol personnel. The purpose of the project was to determine if one of the division’s objectives—reducing infrastructure damage from overweight vehicles—could be better realized by using WIM data when dispatching officers. Data for the project were obtained from Montana’s state truck activities reporting system (STARS), which consists of WIM sites deployed around the state to collect information for a spectrum of Montana DOT activities. In this case, the STARS data were processed to determine the pavement damage caused by overweight vehicles each month during the baseline year. The trends identified from this analysis were used in the subsequent year to direct patrol efforts each month to the five sites that historically had experienced the greatest pavement damage from overweight vehicles. Officers were directed to the specific vehicle configurations historically responsible for the damage, as well as to their direction of travel and time of operation. During this year of WIM-directed enforcement, pavement damage from overweight vehicles decreased by 4.8 million equivalent single-axle load miles, and the percentage of vehicles operating over weight decreased by 20% across all STARS sites (both enforced and unenforced). While changes in loading patterns were observed during the enforcement activities (fewer overweight and more weight-compliant vehicles), the effectiveness of the focused enforcement in producing long-term changes in loading behaviors was uncertain.

Simplified Load Distribution for Vehicles with Nonstandard Axle Gauges

Several simplified methods have been developed to determine the live-load distribution factors for overweight vehicles on slab-on-girder bridges; however, these methods were developed for vehicles with standard axles. Many vehicles exist with nonstandard axle configurations, such as two-wheel axles that are wider than 6 ft (1.83 m) and four-wheel axles with wheels that are evenly or unevenly spaced. For these vehicles, a rigorous analysis is generally desired but is often deemed uneconomical. Therefore, a simplified method should be an asset to the bridge community and the trucking industry. A simplified method for determining live-load distribution factors for vehicles with nonstandard axle configurations is presented. Distribution factor formulas for moment and shear in interior and exterior girders are given. These formulas account for the transverse axle configurations that compose a vehicle. Several two- and four-wheel axle configurations are considered. The distribution factor formulas for slab-on-girder bridges presented in the AASHTO LRFD Bridge Design Specifications are incorporated into the proposed simplified method. The simplified method formulas were developed to approximate the results from a rigorous finite strip method. Comparisons are presented as verification of the accuracy of the simplified method. The simplified method results are usually conservative and correlate reasonably well with the rigorous results. In general, simplified methods worked better for interior girders than for exterior girders, and moment was better predicted than shear.

Innovative Method for Evaluating Overweight Vehicle Permits

Any vehicle whose gross weight exceeds 356 kN (80,000 lb) and/or does not conform to the restriction imposed by the Tennessee Department of Transportation (TDOT) requires a permit issued by TDOT in order to use the Tennessee roads. The current practice in the TDOT Permit Section is that a detailed structural analysis is required for all vehicles with a gross weight over 667.5 kN (150,000 lb). Due to the volume of overload permit applications received, this policy resulted in a large demand in man-hours to perform the structural analysis. Furthermore, the policy does not give consistently safe or conservative assessment. A method has been developed empirically to efficiently extract any suspicious overweight vehicle requesting a permit, regardless of gross weight, for further detailed analysis. The technique utilizes the combination of gross weight, axle loads, and axle spacings. The algorithm can be easily implemented to a computer program for users with limited technical training, since the only input in...

GIS-Based Network Routing Procedures for Overweight and Oversized Vehicles

The objective of this article is to document the development of an automatic procedure for the routing of overweight vehicles with load-carrying and vertical clearance restrictions for the bridges of a highway network. The use of a network routing procedure within a geographic information system (GIS) operating in a PC environment is one of the distinctive features of the proposed approach. The procedure automatically identifies all bridges on a specified route and evaluates the adequacy of the bridge structures as well as vertical and horizontal clearance requirements for a given vehicle. A GIS computerized support methodology consistent with the Texas Administrative Code is developed. In particular, the proposed approach uses bridge load formulas to evaluate the adequacy of bridge structures for incoming overloads. Sample runs of the procedure using Texas data indicate that the procedure is computationally efficient.

Evasion of Weight-Enforcement Stations by Trucks

Highway engineers have become increasingly concerned about the deterioration of the nation’s highway pavements. They suspect that overweight trucks are a primary cause of the problem. Before 1979, the data needed to assess the magnitude of the overweight-truck problem did not exist. Consequently, several studies were conducted to address the magnitude and location of overweight trucking. These studies included efforts to improve truck weight-enforcement programs and to assess the feasibility of using weigh-in-motion (WIM) equipment for weight enforcement. The Florida Department of Transportation (FDOT) undertook the study documented in this paper. The objective of the study was to assess the magnitude, expressed in equivalent single-axle loads (ESALs), of the problem of avoidance of weight-enforcement stations by overweight trucks. The study also considered whether bypassing traffic was local or interstate. FDOT selected the I-95 corridor in the northeast corner of Florida. Two permanent weight-enforcement stations and four bypass route locations were used as traffic monitoring sites. The results of the study indicate that the numbers of overweight vehicles decrease with increasing enforcement activity, but that vehicles attempt to bypass permanent truck weight-enforcement stations. In general, the violations at the permanent weight-enforcement stations were minor, whereas those on the bypass routes were much more severe. These results, when considered with the WIM data and the experience of truck weight-enforcement officers, suggest that only intensive enforcement activity can reduce violations to low levels. Information for enforcement, especially in the definition and quantification of the scale avoidance problem, is provided. Recommendations are made concerning corridor areas and extended and random enforcement operations.