Roadway Maintenance Research Articles

Quantitative analysis of parameters' influence on the stability of coal roadway clamped by upper and lower soft rock with extra thickness

In this paper, a physical model of coal roadway which is clamped by upper and lower soft rock with extra thickness was built according to the characteristics of soft rock strata in china's western mining area. Then, a series of orthogonal numerical experiments were carried out by selecting the strength and stiffness parameters of soft rock and coal seam as well as the in situ stress of soft rock strata as experimental factors and roadway displacements (convergence displacements of sides, displacement of roof to floor) as experimental indexes. By constructing the F statistics with different inspection levels, evaluation method for influence of the experimental factors on stability indexes were defined. Thus, influence degrees of specified parameters on the stability of roadway were divided into five classes as follows: highly significant influence, significant influence, relatively significant influence, little significant influence, and no influence respectively which realize the quantitative analysis of the influence degrees of experimental factors. The finite element calculation results showed that main failure mode of coal roadway that usually showed as tension failure of coal seam in roof and deformation factors of coal seam had the most remarkable effect on roadway displacements. The conclusions provide theoretical basis for further analysis of the mechanism of "roof burst" in roadway maintenance.

Estimating the Consumptive Use Costs of Shale Natural Gas Extraction on Pennsylvania Roadways

The development of natural gas resources in the Marcellus Shale formation has progressed rapidly in the last several years, particularly in the Commonwealth of Pennsylvania. These activities require many heavy truck trips for equipment and materials, which can damage state and local roads that were not designed for high volumes of heavy truck traffic. For state transportation agencies, one measure of costs of shale gas development is the potential degradation of roadways resulting from shale gas development. This technical note, provides a first-order an estimate of roadway consumptive use costs of additional heavy truck traffic on Pennsylvania state-maintained roadways from Marcellus Shale natural gas development in 201, estimated at 1 about $13,000–$23,000 per well for all state roadway types, or $5,000–$10,000 per well if state roads with the lowest traffic volumes are excluded. This initial estimate of costs, is based on data on the distribution of well activity and roadway type in Pennsylvania, estimates for the number of heavy truck trips to construct and operate a single well, the corresponding equivalent single-axle loadings, and estimates of roadway life and reconstruction costs by roadway maintenance class in Pennsylvania.

Network Model for Rural Roadway Tolling with Pavement Deterioration and Repair

AbstractThe objective of roadway tolling in rural areas is often tied to revenue generation for roadway maintenance. Thus, rural pricing models should directly incorporate a pavement deterioration and maintenance model. However, the interactions between these models are not simple, because tolls cause traffic diversion, which in turn affects deterioration rates and forecasted revenue. This article describes a rural pricing model which calculates diversion endogenously with a network assignment model. This model captures deterioration rates and pavement condition in the toll‐setter's objective function, maximizing long‐run net present value of the highway infrastructure. A novel deterioration model is used which is particularly suitable for computational efficiency. The resulting model is discontinuous and nondifferentiable, and involves solving a combinatorial knapsack problem as a subproblem. Thus, a simulated annealing‐based algorithm is presented to solve it, in the framework of a new solution method built upon partitioning the feasible region. A demonstration is made using a network representing the state of Wyoming (28 zones, 60 nodes, and 188 links). Sensitivity analyses reveal that although the locations for optimal tolling are relatively stable as demand changes, the revenue collected can vary substantially. Relatively simple models are used throughout for computational reasons, and future research should investigate strategies for incorporating more advanced pavement and network models.

Road User Fees Instead of Fuel Taxes: The Quest for Political Acceptability

In light of recent regulatory changes in federal fuel economy standards for cars and trucks, the consensus forecast is that motor fuel taxes will not be an adequate source of dedicated funding for roadway maintenance and construction. This article accepts the notion that mileage fees are a promising replacement for the fuel tax and considers steps that might be taken to enhance the political acceptability of such a reform. The authors argue that simple, low‐tech ways of implementing mileage fees are possible in the near term and should be complemented by a well‐developed audit mechanism. Current trends in the automotive and auto insurance industries as well as social media are likely to reduce opposition to more technologically advanced mileage taxes in the long run.

Effect of Snow, Temperature and Their Interaction on Highway Truck Traffic

Based on statistical amount of traffic and weather data sets from three weigh-in-motion sites for the study period of from 2005 to 2009, permanent traffic counters and weather stations in Alberta, Canada, an investigation is carried out to study impacts of winter weather on volume of passenger car and truck traffic. Multiple regression models are developed to relate truck and passenger car traffic variations to winter weather conditions. Statistical validity of study results are confirmed by using statistical tests of significance. Considerable reductions in passenger car and truck volumes can be expected with decrease in cold temperatures. Such reductions are higher for passenger cars as compared to trucks. Due to cold and snow interactions, the reduction in car and truck traffic volume due to cold temperature could intensify with a rise in the amount of snowfall. For passenger cars, weekends experience higher traffic reductions as compared to weekdays. However, the impact of weather on truck traffic is generally similar for weekdays and weekends. Interestingly, an increase in truck traffic during severe weather conditions is noticed at one of the study sites. Such phenomenon is found statistically significant. None of the past studies in the literature have presented the possibility of traffic volume increases on highways during adverse weather conditions; which could happen due to shift of traffic from parallel roads with inadequate winter maintenance programs. It is believed that the findings of this study can benefit highway agencies in developing such programs and policies as efficient monitoring of passenger car and truck traffic, and plan for efficient winter roadway maintenance programs.

Public Opinions of Roadway Assets

In October 2011, the North Carolina Department of Transportation conducted a roadway review with a randomly recruited sample of North Carolina residents and community leaders. More than 300 people from 61 communities participated in the surveys, which were held in six locations: Asheville, Burlington, Charlotte, Jonesville, Rocky Mount, and Wilmington. The purpose of the roadway review was twofold: to determine the expectations for the condition of North Carolina highways and to identify the features that North Carolinians believe are most important on different types of highways. Surveys were completed during both daytime and nighttime hours and covered many roadway maintenance aspects, such as pavement, landscaping and mowing practices, signage, retroreflectivity, and shoulders. Regression equations are also provided to predict the overall satisfaction of condition, safety, and appearance by each individual roadway type.

Feasibility of an Intermodal Terminal in Rural Texas to Enhance Marketing and Transportation Efficiency

This study examines the economic feasibility of investment in an intermodal terminal in west Texas and its implications for reducing roadway maintenance costs and CO2 emissions. The study focuses on cotton, a leading agricultural commodity in Texas, which is highly dependent on the international market and truck transport from west Texas to the Dallas-Fort Worth complex for purposes of accessing containerized railroad transportation to West Coast ports. Analyses were accomplished with a spatial model of the U.S. cotton industry that features details regarding cotton handling, storage, and transportation activities. The analyses indicate an intermodal terminal in west Texas’ intensive cotton-production region to be economically viable, attracting nearly 30% of Texas’ average cotton production. Implementation of an intermodal terminal in west Texas would annually reduce truck travel on state roadways and lower pavement maintenance expenditure by approximately $1 million and reduce CO2 emissions by 42% to 47%.

Best-Value Bid Selection Methods for Performance-Based Roadway Maintenance Contracts

Performance-based contracts for roadway maintenance extend over multiple years and shift the responsibility to the contractor to maintain roadway assets at specific performance levels. Thus contractors need to be selected with best-value methods rather than with the conventional low-bid method. Best-value bid selection considers both the bid price and technical aspects of the proposal (e.g., contractor qualifications, quality management plan, experience). This study evaluated the best-value bid selection methods used by four highway agencies in the United States (Florida, North Carolina), New Zealand, and the United Kingdom to procure roadway maintenance contracts on the basis of performance. A numerical analysis of these four methods indicated that those best-value bid selection methods that used the adjusted price concept balanced price and technical marks, those that used direct price and technical weights favored low bids, and those that considered the maximum technical quality offered by the bidders favored bids with high technical marks.

Probabilistic Approach to Life-Cycle Cost Analysis of Preventive Maintenance Strategies on Flexible Pavements

Preventive maintenance (PM) is recognized as a potentially useful tool to reduce pavement network operation costs. To identify the lowest-cost maintenance and rehabilitation strategies to keep pavement conditions at their desired levels, agencies need to predict conditions on the network accurately. This need presents a challenge because pavement deterioration is a complex mechanism that involves not only structural damage but also the effects of interactions between traffic, material, environment, and time. Earlier studies have based cost analyses on deterministic pavement deterioration prediction models, even though these models lack the capability to capture the random part of true pavement field behavior. An alternative approach is to use probabilistic models, which are built on the basis of observations of in-service facilities and allow a more realistic representation of pavement performance. In this research study, pavement crack initiation models were developed on the basis of stochastic hazard rate modeling techniques. Significantly, model development included data from the California Department of Transportation Pavement Condition Survey so that the effects of a wide range of facilities and environmental conditions could be represented. This study also compared several pavement maintenance scenarios with the use of rehabilitation only as the control case. The study's performance results were then coupled with available cost information to develop life-cycle cost comparisons. The research results confirmed that, compared with rehabilitation alone and maintenance at advance levels of cracking pavement, PM practices significantly reduced long-term costs of roadway maintenance.

Injuries Associated with Underground Coal Mining Equipment in Australia

In the 3 years to June 30, 2008, 4,633 injuries occurring underground at NSW (Australia) coal mines were reported to the insurer. Equipment was involved in 2149 of these injuries (46%). The narrative field accompanying these reports was examined to determine opportunities for controlling injury risks. The most common equipment types involved were: Continuous miner (12% of all underground injuries); Bolting machines (6%); LHD (8%); Longwall (7%); Personnel Transport (4%); and Shuttle Car (3%). The most common combinations of equipment and mechanism were: strains while handling items associated with continuous miner or bolting machines; strains, or being struck by, or caught between, while drilling or bolting on a continuous miner or bolting machine; driving or traveling over rough roads in a variety of equipment; being struck by while operating Longwall equipment. Rare, but high potential consequence events reported during the period included: interactions between personnel and mobile equipment; interactions between personnel and Longwall shield movements; transport equipment collisions. A range of potential short-term control measures for these risks have been identified, including monorails for continuous miner services; redesign of continuous miner platforms and bolting rigs to reduce reach distances during drilling and bolting; improvements to guarding of bolting controls; standardisation and shape coding of bolting controls; two handed fast-speed drilling & bolting; improvements in underground roadway maintenance, vehicle suspension, visibility and seating; and proximity detection devices interlocked with mobile equipment controls. Longer term control measures include automated bolting, and mesh placement, in conjunction with either non-line-of-sight remote control of, or automated, continuous mining machines.

Reliability-based performance simulation for optimized pavement maintenance

Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M&R) activities are extremely costly. Unfortunately, the funds available for the M&R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans.

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.

Assessment of Nighttime Flagger-Illumination Practices

Although flaggers are often an integral component of temporary traffic control measures during roadway construction and maintenance, they may be exposed to significant safety hazards associated with the inadequate illumination of flagging operations. To eliminate these hazards, guidelines are needed that provide specific direction and recommendations for optimal illumination of flaggers. This paper presents the findings of a research study that included the evaluation of selected light equipment under actual working conditions and the development of recommendations for flagger illumination. Three types of light equipment were selected for the study: a 12-V spotlight, a 12-V high-intensity discharge (HID) floodlight, and a light tower with a 2,000 W output. Light equipment testing was performed on two projects in the state of Oregon. The findings reveal that flaggers do not feel comfortable when using 12-V spotlight and 12-V HID floodlight systems because of the small amount of light these systems emit com...

Comparison of mobile and manual data collection for roadway components

The primary objective of this research effort was to compare roadside data collected by typical manual methods – on foot and often requiring traffic control – to data collected by manned data collection vehicles moving with traffic. The research team provided an unbiased comparison of multiple vendors collecting many types of data on various roadway elements including curb, guardrail, signs, pavement markings, and roadway geometry. These data are frequently collected and used by many units within a highway agency such as roadway maintenance, safety, and operations. The research team provided a catalog to each vendor prior to running a 144.8 km (90-mile) test course. The catalog provided a map of the course, a list of each roadway element to be collected, and specific details on how each data element was collected manually. The test course included a variety of highways across a portion of central North Carolina . Multiple data collection companies were given the opportunity to participate, with six actually agreeing to partake and submit data. No vendors supplied sign retroreflectivity data, one submitted pavement marking retroreflectivity data, three submitted roadway geometry data, and five submitted data on roadside elements. The results showed that mobile data compared reasonably well to manual data for most of the desired variables. Mobile data on elements in close proximity to the edge of pavement matched manual data better than elements further from the road. Counts of specific elements were a better fit between mobile and manual data than elements that needed qualitative judgments. Among the major lessons learned is the need for crystal clear specifications before embarking on a mobile data collection program and the desirability of having vendors submit data for a small sample of roadway before embarking on the bulk of a data collection effort.

Evaluation of the Visibility of Workers’ Safety Garments during Nighttime Highway-Maintenance Operations

To reduce traffic congestion in the United States, roadway maintenance and construction operations are widely performed during nighttime hours. This makes visibility a critical issue as workers need to be visible to oncoming traffic and heavy equipment operators in order to ensure their safety. A variety of high-visibility safety garments are available to increase the visibility of workers at night. The study presented in this paper assesses some of these garments from the perspective of drivers. The approach adopted includes the design of a field test setup in which eight safety garment assemblies were displayed in a replicated maintenance work zone. A video was created for each safety garment assembly being worn by workers to capture the approaching view of a driver entering the work zone. The videos were shown to drivers, who evaluated the visibility of the garments in pairwise comparisons. Two random effects binary probit models were estimated. One model was used to understand the characteristics that...

Comparison of life-cycle energy and emissions footprints of passenger transportation in metropolitan regions

A comparative life-cycle energy and emissions (greenhouse gas, CO, NO X, SO 2, PM 10, and VOCs) inventory is created for three U.S. metropolitan regions (San Francisco, Chicago, and New York City). The inventory captures both vehicle operation (direct fuel or electricity consumption) and non-operation components (e.g., vehicle manufacturing, roadway maintenance, infrastructure operation, and material production among others). While urban transportation inventories have been continually improved, little information exists identifying the particular characteristics of metropolitan passenger transportation and why one region may differ from the next. Using travel surveys and recently developed transportation life-cycle inventories, metropolitan inventories are constructed and compared. Automobiles dominate total regional performance accounting for 86–96% of energy consumption and emissions. Comparing system-wide averages, New York City shows the lowest end-use energy and greenhouse gas footprint compared to San Francisco and Chicago and is influenced by the larger share of transit ridership. While automobile fuel combustion is a large component of emissions, diesel rail, electric rail, and ferry service can also have strong contributions. Additionally, the inclusion of life-cycle processes necessary for any transportation mode results in significant increases (as large as 20 times that of vehicle operation) for the region. In particular, emissions of CO 2 from cement production used in concrete throughout infrastructure, SO 2 from electricity generation in non-operational components (vehicle manufacturing, electricity for infrastructure materials, and fuel refining), PM 10 in fugitive dust releases in roadway construction, and VOCs from asphalt result in significant additional inventory. Private and public transportation are disaggregated as well as off-peak and peak travel times. Furthermore, emissions are joined with healthcare and greenhouse gas monetized externalities to evaluate the societal costs of passenger transportation in each region. Results are validated against existing studies. The dominating contribution of automobile end-use energy consumption and emissions is discussed and strategies for improving regional performance given private travel's disproportionate share are identified.

Characterization of pollutants in Florida street sweepings for management and reuse

Disposal and beneficial-use options for street sweeping residuals collected as part of routine roadway maintenance activities in Florida, USA, were assessed by characterizing approximately 200 samples collected from 20 municipalities. Total concentrations (mg/kg or μg/kg) and leachable concentrations (mg/L or μg/L) of 11 metals and a number of organic pollutant groups (volatile organics, semi-volatile organics, pesticides, herbicides, carbamates) in the samples were measured. The synthetic precipitation leaching procedure (SPLP) was performed to evaluate the leachability of the pollutants. From the total metal analysis, several metals (e.g., arsenic, barium, chromium, copper, nickel, lead, and zinc) were commonly found above their detection limits. Zinc was found to have the highest mean concentration of all metals measured (46.7 mg/kg), followed by copper (10.7 mg/kg) and barium (10.5 mg/kg). The metal with the smallest mean concentration was arsenic (0.48 mg/kg). A small fraction of the total arsenic, barium, lead, and zinc leached in some samples using the SPLP; leached concentrations were relatively low. A few organic compounds (e.g., 4,4′-DDT, endrin, and endosulfan II) were detected in a limited number of samples. When the total and leaching results were compared to risk-based Florida soil cleanup target levels and groundwater cleanup target levels, the street sweepings were not found to pose a significant human-health risk via direct exposure or groundwater contamination.

Analyzing the Duration and Prolongation of Performance-Based Contracts through Hazard-Based Duration and Zero-Inflated Random Parameters Poisson Models

Performance-based contracts (PBCs) for roadway maintenance are emerging as a promising contracting approach that offers highway agencies enhanced project control and greater assurance of accountability and product quality. The duration of a PBC is typically longer than that of a traditional contract. Under a PBC, the contractor bears greater risk and responsibility for the final product and is obliged to undertake any required maintenance after the product is completed. A PBC period is typically considered prolonged if both the road agency and the contractor agree that the contract should be extended beyond the original completion date. This paper examines the relationships between PBC duration and prolongation on one hand, and the factors that affect these outcomes on the other hand, while accounting for unobserved heterogeneity. For the PBC duration model, a number of hazard-based function types are estimated. The Weibull model with gamma heterogeneity is found to provide the best fit. For the PBC prolongation model, a zero-inflated random parameters Poisson model is developed to estimate the probability and extent of PBC prolongation. Random variations in the parameter estimates are duly investigated. The size of the contract and whether the contract scope of work includes certain maintenance activities, among other factors, are found to influence the duration and prolongation of PBCs. This paper also computes and interprets elasticities and marginal effects, to shed more light on the individual effects of the influential variables.

Continuous overturn control of compactors/rollers by rollover protective structures

The objective of this article is to report on the effectiveness of Rollover Protective Structures (ROPS) in preventing continuous overturns of compactors/rollers. This study is a case-based analysis of government investigation reports of injury-related overturns of compactors/rollers. The overturns were predominately on construction sites including road and embankment construction in the USA. Other sites included driveway and roadway maintenance or repair and transporting of compactors/rollers either by driving or when loading on or unloading from trailers. The principle intervention observed in controlling a continuous overturn (a roll beyond 90° relative to the impact surface) was the presence of a ROPS on a compactor/roller that serves as an anti-roll bar. The main outcome measures are cases of compactor/roller overturns that are restricted to a 90° roll or are continuous (exceed a 90° roll.) All cases of an overturn in which a ROPS was present resulted in no continuous overturn, and the cases involved with no ROPS averaged an overturn of 301°, showing a propensity for a continuous overturn. This case-based analysis identified a ROPS on compactors/rollers as an effective control for reducing the risk of an overturn to 90° relative to the impact plane.

Fleet Transport for Roadway Maintenance Equipment

Policy, practice, and procedure are addressed relative to the transport of heavy-duty roadway construction and maintenance equipment by department of transportation maintenance personnel. Findings are from a 2-year study sponsored by the Texas Department of Transportation (TxDOT), which focused on a review of TxDOT's existing and future off-road equipment and transport requirements and an assessment of the agency's current knowledge base and practices in transporting off-road equipment. Statewide focus is made in the context of nationwide perspectives on equipment transport. Procedures and practices vary between states, with certain challenges common to all. Relative to equipment, the need exists for newer, better trailers; more lowboy-type trailers; and better trucks. Equipment transport policy is minimal to nonexistent in many states, and transport practices and procedures are sometimes unworkable. Inadequate trailer preventive maintenance, less-than-effective purchasing practices, and poor-quality training programs in regard to equipment load and tie-down are common themes. For Texas, research indicates that overall knowledge of equipment transport is high, especially for practices and procedures, trailer hitches and hitching systems, load securement, chains and tie-downs, and safety. However, equipment transport knowledge about load distribution concepts and practices, training, and compliance with laws and regulations is not as strong. The one thing that field personnel stated would most improve equipment transport at TxDOT would be training. They want more training, better training, and refresher training. Efforts to address these challenges amount to continuous quality improvement to a functional, working system.