bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Hexahydrated Magnesium Chloride Performance as Chemical Stabilizer of Granular Road Surfaces
Authors: Thenoux Guillermo , Vera Sergio
Published: April 2007

The performance was evaluated of hexahydrated magnesium chloride (MgCl2·6H2O) as a chemical stabilizer of granular road surfaces. MgCl2·6H2O is a salt with properties that are useful for chemical stabilization of granular road surfaces, such as its capacity to absorb and retain humidity from its surrounding environment, increase water surface tension, and decrease water vapor pressure. Its effect on the physical and mechanical properties of soils was evaluated in laboratory, and its functional performance and durability were evaluated in field trials. Field trials were performed in arid and semiarid regions in the Atacama Desert in northern Chile. Field results showed that roads stabilized with MgCl2·6H2O remain free of dust and corrugations and exhibit a considerable reduction in pot-holes and surface erosion. The period of effectiveness for MgCl2· 6H2O has proven to be more than 2 years, without any type of road maintenance.
Stabilizing Unpaved Roads with Calcium Chloride
Authors: Monlux Stephen
Published: April 2007

The U.S. Department of Agriculture Forest Service has stabilized unpaved road surfacing materials with relatively high concentrations of calcium chloride salt. The percentage of calcium chloride is higher than that traditionally used for dust abatement or aggregate base stabilization. Up to 2% pure salt by weight of aggregate was mixed into the top 2 in. (50 mm) of both aggregate and native road surfaces. The results were monitored for 2 to 4 years. The stabilized road surfaces resisted raveling and washboarding for several seasons and significantly reduced road blading and aggregate loss. As a result, calcium chloride stabilization may be a cost-effective treatment for roads with daily traffic volumes less than 200. Other benefits include reduced surface erosion and sedimentation; improved safety from reduced dust, raveling, and washboarding; and less frost penetration. Encouraged by these results, the Forest Service is conducting additional evaluations to determine the cost-effectiveness of surface stabilization with both magnesium chloride and calcium chloride in different environments and with different aggregate materials.
Development of Stabilizer Selection Tables for Low-Volume Roads: Arlington, Texas
Authors: Phillips Martin , Puppala Anand J. , Melton Keith
Published: April 2007

Expansive soil movements cause damage to low-volume traffic roadways, which is attributed to the low rigidity of the materials used in the pavements. Several treatment methods have been used to stabilize expansive, soft subsoils, which have yielded mixed results due to the presence of sulfates. Because of the ambiguity of these results, the city of Arlington, Texas, established a task force of researchers and practitioners in the area of soil stabilization to develop matrix tables of the various treatment methods and their applicability to stabilize expansive, soft, and sulfate-rich soils. Extensive literature compiled on the stabilizers, several new and previous research studies on stabilizers, and the expertise of the task group members were considered in the evaluation process. The task force developed seven matrix-form selection tables that showed various treatment methods and if their applications were acceptable or unacceptable for the 12 types of soft and sulfate-rich subgrade soils. A summary of the tables was prepared, along with guidelines on how to use these tables to screen the potential stabilizers for pavement construction projects.
Simplified Methods for Evaluating Road Prism Stability
Authors: Elliot William , Ballerini Mark , Hall David
Published: April 2007

Mass failure is one of the most common failures of low-volume roads in mountainous terrain. Current methods for evaluating stability of these roads require a geotechnical specialist. A stability analysis program, XSTABL, was used to estimate the stability of 3,696 combinations of road geometry, soil, and groundwater conditions. A sensitivity analysis was carried out to find the most important site-specific variables in estimating slope stability, and two regression equations were developed to predict the factor of safety ( FS) for a given road, one with the groundwater below the road fill and one with the groundwater in the road fill. The resulting equations predicted failures on road segments where failures were observed to have occurred. A comparison of the predicted FSs from the regression equations with the FS values predicted by the infinite slope equation showed that both methods predicted similar FSs.
Determination of Superpave® Gyratory Compactor Design Compactive Effort for Cold In-Place Recycled Mixtures
Authors: Cross Stephen A.
Published: April 2007

Cold in-place recycling (CIR) is a viable pavement rehabilitation technique that recycles 100% of the reclaimed asphalt pavement (RAP) in place, without the addition of heat. One of the barriers to the use of CIR has been the lack of a suitable mixture design procedure. Researchers at the University of Rhode Island have shown that Superpave® mix design technology is applicable to CIR mixtures if the mix design compactive effort [number of compaction revolutions or gyrations ( Ndesign)] can be established for the Superpave gyratory compactor (SGC). The two objectives of the present project were to determine the mix design compactive effort ( Ndesign) with the SGC required to match the field densities of CIR mixtures and to evaluate the effect of sample compaction before and after breaking of the emulsion on the Ndesign compactive effort. RAPs from seven CIR projects were obtained, as was asphalt emulsion from each project. Samples were compacted with the SGC by use of the mix water and emulsion content from the field. The change in density with the number of compaction revolutions was monitored, and the Ndesign required to match the field density was determined. The effects of RAP physical properties, such as RAP gradation, the percentage of flat and elongated particles, aggregate gradation, and angularity, on Ndesign were evaluated. RAP shape, as measured by the percentage of flaky pieces, was found to influence the compacted field density. The Ndesign compactive effort for CIR mix design was also established.
Long-Lasting Gravel Roads: Case Study from the United States
Authors: Selim Ali A. , Skorseth Kenneth O. , Muniandy Ratnasamy
Published: April 2007

Gravel surfacing is commonly used on low-volume roads in rural areas of the United States to form farm-to-market networks that contain more than a million miles of unpaved roads. Some of these roads carry appreciable amounts of trucks and farm machinery. Some of these roads, if properly designed and constructed, can last a long time. One such road is in Hand County, South Dakota. This road was constructed in 1963 and has never been rehabilitated or reconstructed since its construction, and it has shown excellent performance for more than 37 years. This road normally carries less than 200 vehicles per day, but significant numbers of heavy trucks use the road. This exceptional performance led to an investigation of the reasons why that road lasted as long as it did without major maintenance or rehabilitation. Although this type of road construction is common in other nations, under different names, the practice of constructing this type of road in the United States was done without documented specifications. The main objectives of the study were to determine all factors that contributed to the longevity and the remarkable performance of this road through field and laboratory investigations. Field investigations with a dynamic cone penetrometer (DCP) revealed that both the quality and the quantity of aggregate base were more than adequate. Although the subgrade soil was classified as A6 according to AASHTO soil specifications, it provided good support according to DCP data. Tests of the flatness and elongation of the coarse aggregate and the angularity of the fine aggregate also revealed satisfactory results. Gradation tests also revealed compliance with specifications.
Stabilization and Structural Design of Marginal Materials for Use in Low-Volume Roads
Authors: Liebenberg J. J. E. , Visser A. T.
Published: April 2007

The present structural design method available for bitumen emulsion-treated materials is mostly based on the experience of road engineers and does not provide the necessary guidelines for mechanistic analysis and design. Emulsion treatment is being used more frequently to improve marginal materials and rehabilitate existing badly deteriorated road. Research was conducted on the structural performance of emulsiontreated materials under heavy-vehicle simulator (HVS) and laboratory testing. The issues considered included strength, fatigue, and permanent deformation. The results showed that the emulsion-treated material has a two-phase behavior, namely, a precracked phase and a postcracked phase. The tests also showed that the material has a high degree of resistance to permanent deformation. The laboratory tests showed that cement contributes to the strength of the material, whereas the addition of enough emulsion improves the flexibility. The HVS testing data were used to develop preliminary structural design models for fatigue and permanent deformation.
Design and Construction of Low-Cost, Low-Volume Roads in Australia
Authors: Bullen Frank
Published: April 2007

Inexpensive roads constructed by using local knowledge of material behavior have been shown to be capable of meeting rural traffic requirements without the need for importation of hard and expensive quarried crushed rock or gravel. In Australia, low-cost, low-volume roads are typically rural roads constructed in a broad range of operating environments, varying from arid to tropical. The areas that contain the longest length of rural roads, however, are arid or semiarid and are often subjected to periods with low levels of precipitation and high levels of evaporation, frequently followed by periods of intense rainfall. Locally available materials for road making may not meet the usual standard road authority requirements for high-quality aggregate and are thus termed “marginal,” “nonstandard,” or even “inferior.” Because these materials are a resource that cannot be ignored, locally derived specifications are formulated for specific materials to allow more efficient expansion and maintenance of road networks in remote rural areas. Many of the subgrades within arid and semiarid areas are sensitive to water ingress and are termed “cracking” or “expansive” clays. The combination of hostile environment, poor subgrade, and marginal construction aggregates means that the engineer must take an entrepreneurial approach when developing the rural road infrastructure. Some of the methods used to develop and maintain a highway infrastructure for remote rural areas in Australia are outlined, with the Western Queensland region used for illustrative purposes.
Locally Available Aggregate and Sediment Production
Authors: Foltz Randy B. , Truebe Mark
Published: April 2007

Selection of suitable locally available materials to build strong and durable roads with aggregate surfaces is desired to minimize road construction and maintenance costs and to minimize the detrimental effects of sedimentation. Eighteen aggregates were selected from local sources in Idaho, Oregon, South Dakota, and Washington State. Aggregate was placed in shallow metal frames and compacted to simulate a forest road. The levels of runoff and sediment from a highintensity, long-duration simulated rainstorm were measured. The material tests selected for use in the study included ones that define the basic characteristics of the aggregate, along with a number of tests intended to predict susceptibility to erosion. Each of the tests was statistically evaluated to identify those that best predicted the perceived aggregate quality. The two best indicators of aggregate quality were the results of the sand equivalent test and the P20 portion of the Oregon air degradation test. The best indicator of either runoff or sediment production was the fraction passing the 0.6-mm sieve. Acceptable aggregates, both those of good quality and those of marginal quality, exhibited a 2-order-of-magnitude range in both runoff and sediment production.
Contact Pressures and Energies Beneath Soft Tires: Modeling Effects of Central Tire Inflation–Equipped Heavy-Truck Traffic on Road Surfaces
Authors: Douglas Robert A. , Woodward W. D. H. , Rogers Robert J.
Published: April 2007

Much has been made of the use of tires with low-inflation-pressure systems called central tire inflation (CTI) systems. Great benefits have been noted in numerous trials, including the reduced requirement for truck maintenance, improved gradeability, longer tire life, improved ride for drivers, reduced road rutting, and reduced road maintenance. Reports of successful field trials in the literature are confirmed by other supporting theoretical studies. However, the studies reported in the literature tend to relate to unsealed, unbound roads. Given that in some quarters there is now a desire to extend the benefits of the use of CTI to sealed roads, new questions arise. A full-scale, laboratory study was carried out at the University of Ulster, Northern Ireland. Both the normal and shear contact stresses were measured with a high-speed data logger connected to electronic sensors in the apparatus’s bed plate, as a tire ran over them. Tire pressures and loads were varied in this factorial study. The contact stresses were measured, and conclusions based on their distribution across the tire “contact patch” were presented. In addition, contact energies were inferred, and the consequences for sealed pavements were suggested.
Impact of Heavy Vehicles on Low-Volume Roads
Authors: Sebaaly Peter E. , Siddharthan Raj , Huft David
Published: April 2007

A recent study sponsored by the South Dakota Department of Transportation evaluated the impact of agricultural equipment on the actual response of low-volume roads. To meet this objective, one gravel pavement section and one blotter pavement section were instrumented in South Dakota and tested under agricultural equipment. Each section was instrumented with pressure cells in the base and subgrade and deflection gauges to measure surface displacement. Field tests were carried out during fall 2000, spring 2001, and summer 2001. Testing in different seasons offered the opportunity to evaluate the impact of heavy equipment on low-volume roads under variable environmental conditions: high and low temperatures and wet and dry conditions. Test vehicles included two Terragators, a grain cart, and a tracked tractor. The field testing program collected the pavement responses under five replicates of each combination of test vehicle and load level and under the 18,000-lb single-axle truck. Data were examined for repeatability, and the average of the most repeatable set of measurements was calculated and used in the analysis. The first part of the research evaluated the relative impact of the different equipment, defined as the ratio of pavement response under each combination of vehicle-load level over the pavement response under the 18,000-lb single-axle truck. Analysis of the pavement response ratios indicated that ( a) the tracked tractor is not more damaging than the 18,000-lb single-axle truck, ( b) Terragators 8103 and 8144 are more damaging than the 18,000-lb single-axle truck only when they are fully loaded, and ( c) the grain cart is more damaging than the 18,000-lb single-axle truck only when it is loaded over the legal load limit. The second part of the research evaluated load equivalency factors for agricultural equipment on gravel and blotter pavements. Analysis of the load equivalency data indicated that an agency can effectively reduce the impact of agricultural equipment on a low-volume road by increasing the thickness of the base layer and keeping the load as close to the legal limit as possible.
Assessment of Interaction Between Road Roughness and Heavy Vehicles
Authors: Hassan Rayya A. , McManus Kerry
Published: April 2007

Road surface roughness excites low- and high-frequency vibration modes of a heavy articulated vehicle body. These vibrations result in motions in all directions that detract from the driver’s perceived ride and comfort and increase pavement damage due to dynamic wheel loads (DWLs). A subjective assessment survey was conducted to identify surface roughness characteristics that mainly influence the perceptions of heavy-vehicle drivers of pavement rideability and their comfort. The latter was achieved by correlating drivers’ ratings to roughness contents in different roughness wavebands. The results indicated that the drivers mainly object to low-frequency body vibrations excited by roughness wavelengths in the range of 4.88 to 19.5 m. Roughness content in this band was used to establish a new profile-based index called the profile index for truck ( PIt). Drivers consider pavement rideability to be poor when PIt exceeds 2.75 m/km. PIt provides better predictions of heavy vehicle ride than the international roughness index (IRI). The methodology for developing the PIt and assessment of its reliability as a measure of heavy vehicle ride are described. The latter was achieved by testing the statistical significance of the effects of factors other than road roughness that influence the perceived ride of truck drivers. They include factors related to the vehicle, the road, and the driver as well as situational factors. In addition, PIt was found to be a better indicator than IRI of the levels of whole body vibrations transmitted to the driver through the seat and a better predictor of the magnitude of DWL to which the test pavements are subject.
Solutions of Gravel Road Renovation Based on Certain Local Conditions in Lithuania
Authors: Zilioniene Daiva , Cygas Donatas , Dundulis Kastytis
Published: April 2007

The Lithuanian state road network consists of more than 21,000 km of roads, and gravel roads dominate (43.3%). While the 1998–2000 Paving of Gravel Roads Program was being implemented, there were a few issues in estimating investments that could determine the implementation alternatives of the rehabilitation project. Total costs of renovated gravel roads depended on the climate and geological and hydrological conditions of a location as well as traffic and gravel road characteristics. Roads, like engineering buildings, have to be of sufficient strength and durability, and they should correspond to traffic volume. The results of tests showed diversity of pavements and the characteristics of renovated gravel roads. Gravel roads vary by road width, pavement structure, pavement materials, and traffic. In analyzing traffic on gravel roads, the roads were classified into four groups according to traffic volume. Frequently, the strength of subgrade soils determines the structure of renovated gravel roads. The authors carried out tests on road subgrades under different geomorphologic and geological conditions, estimating the structure, physical conditions, and mechanical properties of these subgrades. According to the test results the strength of existing gravel roads depends on the strength of the subgrade, the thickness of the gravel road, and the quality of the gravel. The equivalent deformation modulus of the gravel roads is described by a binomial. In selecting structures for reconstruction of gravel roads, mathematical models are suggested.
Techniques for Extending the Life of Low-Volume Roads in Seasonal Frost Areas
Authors: Kestler Maureen A.
Published: April 2007

Major highways are designed to withstand heavy vehicles and high traffic volumes year round. However, low-volume roads (LVRs) in seasonal frost areas are extremely susceptible to damage from trafficking by heavy vehicles during spring thaw. As a result, the maintenance-free life of an LVR in a seasonal frost area averages less than half that of a similar road in a nonfrost area. This study serves as a practical primer on addressing thaw weakening of LVRs: it offers guidance for identifying frost-susceptible soils, summarizes methods used and currently undergoing research to determine when conditions are critical, and provides several solutions for avoiding the costly impact of spring thaw on LVRs. Diagnostic tools and recommended road-usage techniques are provided for existing roads; alternative design techniques are presented for new and reconstructed roads. Tools and techniques are applicable across much of Europe, North America, and Asia; some also apply to wet areas outside seasonal frost areas.
Analysis of Deterioration Models for Lightly Loaded Thin Seal Flexible Pavements
Authors: McManus Kerry J. , Metcalf John B.
Published: April 2007

A set of deterioration models is required to manage local government authority (LGA) pavements in a cost-effective manner; yet, most existing deterioration models have been derived for the major highways of the State Road Authority system. LGA pavements are different in terms of pavement life, the effect of the environment, loading, and expectations of performance with respect to riding quality. There is a greater emphasis on sustained light routine maintenance in LGAs. There is a need to develop models that more closely represent LGA pavements so they can be used to forecast the deterioration of the asset and to provide better guidance for rehabilitation planning. Existing pavement deterioration models, such as Highway Development Management-III (HDM-III), were examined for application to the Australian LGA pavement set. In general, such models were too complex for use in LGAs, and they also used roughness as a performance measure. Roughness is not commonly measured in LGA pavement networks. Other studies have shown that HDM-III could overestimate the deterioration of lightly loaded pavements. For this study, data on deterioration of several LGA pavements were collected and analyzed. Visual assessment data on pavement condition were captured in a “snapshot” survey of pavements of different ages. Thus, the data represent an age cross-section sample. Little or no correlation was found between any of the performance indicators and age when the full data sets were used for the analyses. Some correlation was apparent with the averaged data for each age. Even then, some of the trendlines observed indicated a performance with age, contrary to normal expectations. It appears that factors besides age have a significant influence on the behavior of LGA pavement.
Otta Seals and Gravseals as Low-Cost Surfacing Alternatives for Low-Volume Roads: Experiences in South Africa
Authors: Oloo Simon , Lindsay Rob , Mothilal Sam
Published: April 2007

The geology of the northeastern part of the province of KwaZulu–Natal, South Africa, is predominantly alluvial with vast deposits of sands. Suitable gravel sources are hard to come by, which results in high graveling and regraveling costs brought about by long haul distances and accelerated gravel loss. Most gravel roads carry fewer than 500 vehicles per day of which less than 10% are heavy vehicles. The high cost of regraveling has led to consideration of upgrading such roads to surfaced standard, even though traffic volumes do not justify upgrading. Traditional chip seals are expensive and cannot be economically justified on roads that carry fewer than 500 vehicles per day. The KwaZulu–Natal Department of Transport is actively involved in efforts to identify cost-effective alternative surfacing products for low-volume roads. Field trials were conducted with Otta seals and Gravseals, which have been used successfully in other countries, as low-cost surfacing products for low-volume roads. The Otta seal is formed by placing graded aggregates on a relatively thick film of soft binder that, because of traffic and rolling, works its way through the aggregates. Gravseal consists of a special semipriming rubberized binder that is covered by a graded aggregate. Both Otta seals and Gravseals provide relatively flexible bituminous surfaces suitable for low-volume roads. Cost savings are derived mainly from the broad aggregate specifications, which allow for the use of marginal materials.
Pavement Evaluation and Rehabilitation Design Methodology Currently Used on Low-Volume Roads in Southern Africa
Authors: Grobler J. A. , Taute A. , Joubert I.
Published: April 2007

A pavement evaluation and rehabilitation design methodology is currently employed in southern Africa on relatively light pavement structures used for low-volume roads. The pavements normally consist of natural gravel materials in most layers and thin bituminous surfacings. When nearing the end of their design lives, they exhibit distresses ranging from minor deformation through aging of the surface to structural cracking and potholes. Rehabilitation options normally involve light stone seals or other inexpensive and cost-effective treatments. The phases of investigation for pavement evaluation and rehabilitation designs start with desk study to establish the history of the road and its past performance from pavement management system outputs. Detailed visual evaluations are then conducted of road features and extent of various forms of distress. These data are presented followed by a decision-making process to select areas for more detailed testing. All the information is used to determine the causes of distress and likely rehabilitation alternatives. Further destructive and nondestructive testing is carried out to predict performance of rehabilitation designs and equivalent annual cost comparisons. Rehabilitation design is also done with use of the dynamic cone penetrometer. Decision criteria are set for use of tests undertaken in the assessments, and test results are evaluated. This procedure normally results in a wide range of rehabilitation options, from application of a diluted emulsion as a surface rejuvenator to more extensive patching and resealing to major rehabilitation and overlays. This process effectively produces cost-effective solutions that maximize limited budgets. It is essential that the road authority be prepared to share the risks of the low-cost options with the designer. In this way benefits of low-cost solutions are realized, whereas, in a limited number of instances, premature distress may have to be repaired under routine maintenance.
Low-Water Stream Crossings: The Iowa Experience
Authors: Gu R. R. , McDonald T. J. , Lohnes R. A.
Published: April 2007

Replacement of old, unsafe bridges on low-volume roads is an increasing concern in rural America. Counties and local jurisdictions with inadequate bridges on secondary roads are faced with large capital expenditures for replacement structures or possible road closings. Low-water stream crossings (LWSCs) can provide a low-cost and reasonably safe alternative. Three types of LWSC are unvented fords, vented fords, and low-water bridges. A study was conducted to develop design guidelines for all three types of LWSC. Although the study focused on Iowa, the results are thought to be applicable to a wider geographic region. The salient features of this design process, including site selection, selection of most effective LWSC type, and geometric and material selection design, are described for the three types of structures. Although potential legal liability associated with LWSCs is a concern, the Iowa experience indicates that, with adequate warning signs, accidents and subsequent tort claims may actually be less with LWSCs than with deficient and obsolete bridges. On the basis of this history, it appears that potential liability from the use of prudently designed LWSCs is not a high risk. However, each state and local agency should thoroughly study code and local ordinance restrictions when considering LWSC options.
Geosynthetic-Reinforced Soil Bridge Abutments
Authors: Keller Gordon R. , Devin Steven C.
Published: April 2007

Geosynthetic-reinforced soil (GRS) bridge abutments have been used on a number of bridge projects over the past decade. This adaptation of reinforced soil technology to bridge structures and their approach fills offers an excellent opportunity to simplify construction, reduce construction time, and reduce cost on structures for which this technology is appropriate. This design concept, in which the actual bridge superstructure rests upon the GRS abutment wall, minimizes differential settlement and eliminates the problematic “bridge bump” found on many structures. The technology has been adapted to both road and trail bridges. The basic design concept of GRS used in bridge abutment applications was evaluated, along with its advantages and disadvantages. Some selected case histories of GRS bridge abutments on low-volume roads and trails in Alaska and California were considered. In addition, the Mammoth bridges, in the mountains of northern California, with high design snow loads and high horizontal peak ground accelerations, afforded an opportunity to design, construct, and monitor GRS-supported spread-footing abutments under difficult service conditions.
Fiber-Reinforced Polymer Composite Bridges in West Virginia
Authors: Shekar Vimala , Petro Samer H. , GangaRao Hota V. S.
Published: April 2007

Fiber-reinforced polymer (FRP) composites have been used more often over the past decade than before in new construction as well as in repair of deteriorated bridges. Many of these bridges are on low-volume roads, where they receive very little attention. It is imperative that new bridge construction or repair be long lasting, nearly maintenance free, and as economical as possible. Relative to those factors, FRP composite bridges have been found to be structurally adequate and feasible because of their reduced maintenance cost and limited environmental impact (i.e., no harmful chemicals leaching into the atmosphere with longer service life). In West Virginia, 23 FRP composite bridges have been constructed, among which 18 are built on low-volume roads that have an average daily traffic (ADT) of less than 1,000, including 7 with ADT less than 400. General FRP composite bridge geometry and preliminary field responses are presented as are some of the preliminary construction specifications and cost data of FRP composite bridges built on low-volume roads in West Virginia
Network Design for Intermodal Barge Transport
Authors: Konings Rob
Published: April 2007

During the past decade intermodal barge transport has been very successful in gaining market share in northwest Europe. The barge sector has been able to cater very well to the ever–increasing demands of shippers. It is now a leading mode of transport along the major river corridors and is opening new geographical markets. These successful developments are due to the beneficial cost–quality features of intermodal barge transport compared with its main competitor, unimodal road transport. However, to remain competitive in existing markets and to expand into new market areas the cost–quality features of intermodal barge transport must be improved. Network operations are important influences on the cost–quality performance. Which barge network operations provide the best performance, however, depends on the transport market to be served. This relation between barge network design, transport market, and the performance of intermodal barge transport is the central issue discussed. A general framework for barge network design is presented describing the design variables for barge networks and showing their relationship to the performance indicators of intermodal barge transport. Given the quantitative relations between the design variables for barge networks, it is possible to assess the performance of different types of barge networks for different transport markets. This tool is empirically demonstrated in a case study on the Rhine River. It demonstrates that changing the network operations will lead to further improvement of the competitiveness of intermodal barge transport in this corridor.
Ports of Long Beach and Los Angeles Transportation Study
Authors: Cartwright Kerry , Cottrill Larry , Hamrick Gary , Leue Michael , Nye Larry
Published: April 2007

In 2001, 9.65 million 20-ft-equivalent units of containerized cargo moved through the Ports of Long Beach and Los Angeles. The ports are ranked third in the world in relation to containerized cargo, and first in the United States. Their existing throughput is expected to triple in the next 20 years. To adequately address the continued robust growth in international trade and corresponding cargo throughput, the ports have jointly prepared a transportation study. The study is the first comprehensive areawide analysis of the ports since the early 1980s and the first study that includes an integrated intermodal logistics analysis. In addition to logistics, the disciplines of transportation planning, traffic engineering, and civil engineering have been employed in the study. The ports transportation study includes detailed analyses of transportation system access in and immediately adjacent to the port area and a regional transportation system access analysis. The basic objectives of the study include the following: ( a) determine port and nonport truck traffic growth, ( b) develop transportation planning tools to address port growth, ( c) identify existing and future transportation system deficiencies in and around the ports, and ( d) recommend physical and operational improvements to mitigate future system deficiencies.
Transferability of an Intermodal Freight Transportation Forecasting Model to Major Florida Seaports
Authors: Klodzinski Jack , Al-Deek Haitham M.
Published: April 2007

Seaports are important economic generators, and identifying necessary infrastructure improvements is essential to accommodate potential growth at these intermodal facilities. The ability of heavy trucks to access a port’s freight terminals is one such operational improvement that needs to be addressed. Freight activity from Florida’s major seaports generates more than 10,000 trucks per day. Efficient accessibility to freight terminals and storage facilities at ports can be provided by identifying needed improvements in transportation operations and by developing truck trip generation models to forecast truck trips in and out of the ports. In July 2001 an artificial neural network (ANN) model was developed successfully by using backpropagation techniques to simulate the transportation of freight by heavy trucks generated from an intermodal activity center such as a seaport. The general methodology for developing the model was applied to the Port of Tampa and Port Canaveral in Florida to test the transferability of the ANN modeling technique. From daily vessel freight data, models for both ports were developed successfully and validated at the 95% confidence level with data collected from the field. The validated models were executed for short-term forecasts of truck trips at both ports. Port of Tampa was forecast to have a 0.31% average annual decrease in heavy trucks, attributed to the decreasing trend in bulk commodity shipments. A 5.07% average annual increase was forecast for Port Canaveral, which correlated with historical trends and future estimates for freight activity. Output from these models can be directly used as truck variable inputs to route assignment models used by local and regional government agencies.
Economic Impacts and Public Financing of Port Capacity Investments: The Case of Rotterdam Port Expansion
Authors: Dekker S. , Verhaeghe R. J. , Pols A. A. J.
Published: April 2007

Ports, as well as large-scale infrastructure in general, require substantial investments from public and private sources and generate direct and indirect benefits for society. Ports also have associated external impacts: negative impacts on the environment as well as traffic congestion. Competition between seaports has increased substantially. As a result, the efficient use of port facilities has received more emphasis. The traditional role of government in providing such facilities is increasingly being questioned. Public and private roles need to be differentiated more clearly. These factors cause a rising interest in untangling issues of public versus private financing of investments in port improvements; a workable concept for public financing of port investments is called for. A concept is presented for differentiating public and private portions in financing port investments. The public contribution is based on and justified by the indirect economic impacts of the total investment project. The concept is illustrated by data included in the cost–benefit analysis of the proposed second seaward expansion of the port of Rotterdam.
Transportation Developments in South America and Their Effect on International Agricultural Competitiveness
Authors: Fuller Stephen , Yu Tun-Hsiang , Fellin Luis , Lalor Alejandro , Krajewski Ricardo
Published: April 2007

Argentina and Brazil have emerged as major U.S. competitors in world grain markets. The effect of recent and planned transportation infrastructure improvements on their international competitiveness is to be determined. Existing and planned transportation system improvements in South America that increase transportation and logistical efficiency on export-grain corridors are identified, and with the use of spatial models of the international corn and soybean economies, the effect of the enhanced transportation efficiency on international competitiveness is evaluated. Results show that the transportation system improvements yield noteworthy gains in South America, with producer revenues increasing by more than $1 billion per year and annual exports increasing by 3.3 million metric tons. As a result of South America’s improved transportation infrastructure and its increased exports, world grain prices decline and projected exports and producer revenues in the United States are reduced.
U.S. Containerized Grain and Oilseed Exports: Industry Profile
Authors: Vachal Kimberly , Reichert Heidi
Published: April 2007

Diversification of production agriculture has received much attention in recent years. As producers and customers adapt to technologically advanced production and marketing systems, it is important to consider opportunities available for adding value to raw grain through alternative handling and transportation options. One such opportunity that has been more widely recognized in recent years is marketing grain products via container. It has been estimated that this option is currently used in marketing about 1% of U.S. grain production, with growth to 3% expected in the next 5 years. A profile is presented of the U.S. containerized grain and oilseed export industry, including marketing activities, future expectations, information needs, and business practices. Information developed concerning shipment origins, commodity volumes, and market destinations provides an industry profile that might be used as a tool in research, development, planning, and enhancement of opportunities for containerized marketing of grain products.
Geographic Information System-Based Digital Catalog for Managing Subsurface Geotechnical and Geologic Data
Authors: Veeger Anne I. , Murray Daniel P. , Hermes O. Don , Boothroyd Jon C. , Hamidzada Nasir
Published: April 2007

Knowledge of surface and subsurface geology and geotechnical properties is fundamental to planning, developing, and modernizing transportation systems. Through dynamic coupling of readily available areal geographic information system coverages and subsurface borehole data stored in a relational database, a spatially referenced digital catalog of borehole data was created for two pilot areas in Rhode Island. The borehole database was populated with data derived from Rhode Island Department of Transportation geotechnical reports and supplemental data from the U.S. Geological Survey groundwater site inventory system and local storm water and sewer projects. Most of these data were previously maintained in paper format, making historical or interproject data comparisons virtually impossible. Unification of these data in a single relational database yields two primary benefits: ( a) historical data are readily accessible for review and therefore can be incorporated easily into the planning stages of new projects and ( b) sophisticated analysis of the region becomes possible with access to data from multiple projects with both spatial and temporal coverage. Geologic data include bedrock geology, surface outcrops, unconsolidated materials, soil type, topographic and orthophotographic base maps, and location of boreholes and wells. Subsurface data include land surface elevation, depth to water table, depth to bedrock, presence of fill, high and low blow-count zones, and organic sediment. The digital catalog is distributed on a CD-ROM that includes ArcView project files and an Access relational database. The borehole data are also accessible through the Internet, with retrieval access for all users and data entry privileges for registered users.
Electronic Data Collection for Rockfall Analysis
Authors: Bellamy Derrick , Bateman Vanessa , Drumm Eric C. , Dunne William M. , Vandewater Christopher , Mauldon Matthew , Rose Brett
Published: April 2007

Rockfall analysis traditionally has used conventional stationery tools, that is, pencil and paper, for data collection. Traditional methodologies are being revisited with the advent of personal digital assistants (PDAs) or pen-based computers that enable field data to be collected electronically. The advantages over data collection with pencil and paper include automatic error and data integrity checks during data input and the elimination of manual data entry. PDAs also allow automatic branching to solicit data input on the basis of previous data entered and support for code or scripting, which can be used to create unique files names from the data entered. These advantages are illustrated in an electronic data collection methodology as implemented within a rockfall hazard rating system for the Tennessee Department of Transportation.
Optimization Approaches for Efficient Container Security Operations at Transshipment Seaports
Authors: Lewis Brian M. , Erera Alan L. , White Chelsea C.
Published: April 2007

An approach is described for aiding managers of a container-transshipment seaport in understanding the balance between the number of containers to undergo security inspection and two alternative objectives: first, the vessel cost as measured by the concomitant departure delays of outbound vessels and, second, the port costs as measured by the total number of container moves. Security concerns heightened by the events in the United States on September 11, 2001, have resulted in the U.S. Customs Service’s seeking partnerships with foreign ports so that some containers bound for the United States might undergo security checks before they enter that country. However, outbound-vessel departure delays and additional container moves in the yard associated with security checks could create significant costs and negatively affect the competitive position of a port. A best-first optimal search procedure, A*, is used to solve a simplified container-yard management problem for transshipment seaports. A methodology is developed to optimize transshipment-container movements from inbound vessels to outbound vessels through yard-storage areas when a subset of the containers must be moved to an inspection area for a security check. It is assumed that the container stow plans for the inbound and outbound vessels are known and that the containers to be inspected have been determined by regulatory agencies before ship arrival. Modeling details and extensions of the problem are discussed. Due to the intractability of the generic A* technique for problems of realistic size, a fast heuristic based on simple rules is developed for a simplified transshipment model. Finally, a modified A* algorithm incorporating both fast optimal rules and a branching procedure is introduced.
Assessing Emergency Preparedness of Transit Agencies: Focus on Performance Indicators
Authors: Nakanishi Yuko , Kim Kibeum , Ulusoy Yavuz , Bata Andrew
Published: April 2007

In any emergency situation, a certain degree of confusion and chaos occurs. The more organized and orderly the response effort, the more likely that lives may be saved and property preserved. Emergency preparedness can enable transit agencies to react to an emergency on or off transit property. Evacuations and transport of emergency police, fire, and emergency medical technician personnel to and from the incident site may be facilitated by using transit vehicles. Because emergencies do not occur frequently, it is unadvisable to wait until they happen to evaluate a transit agency’s level of emergency preparedness. Instead, proposed is the development of performance indicators that measure the achievement of emergency preparedness goals and policies of a transit agency. An emergency preparedness assessment flowchart incorporating performance indicators was developed. Overall emergency preparedness indicators and sample performance indicators for each component are suggested along with standards and data sources for the indicators. In addition, the use of cost–benefit analysis is suggested to facilitate security-related investment decisions by agency management.
E-Smart Threat Agent System
Authors: Fisher Rodney A. , Schlicht Roger
Published: April 2007

The Environmental Systems Management, Analysis and Reporting neTwork (E-SMART) was developed as a system of smart sensors; active controls; and data acquisition, data reduction, and adaptive decision software to sample, analyze, and report on environmental contamination and cleanup activities on an installation. The prototype system was installed and demonstrated and is operating at Tinker Air Force Base (AFB), Oklahoma. The system is based on ANSI/EIA-709.1-A networking protocol originally developed for building environmental systems automation and process control. Sensor interfaces have been developed that allow E-SMART to network commercial off-the-shelf “smart” or “dumb” environmental sensors, new innovative sensors, or both. The network architecture can support communications media connections via wire, radio frequency, fiber optics, and so on. The system has been on line at Tinker AFB since 1998 and originally consisted of about 100 sensors and has a present array of 30 sensors, measuring up to six variables each. Most recently, development has begun to expand the E-SMART sensor suite to include threat-agent sensors: E-SMART → E-SMART Threat Agent (E-SMART TA). This effort is integrating online chemical and biological sensors and monitoring systems to demonstrate an E-SMART TA system to enhance protection, warning, and response. The emphasis is on maximizing adaptability and flexibility by accepting the widest possible variety of toxic industrial chemical and material and chemical and biological agent sensors (current, emerging, and future), responding to a wide range of deployment and employment requirements, having the capability to incorporate existing and future analysis models, and providing data sharing and interoperability across all users, U.S. Department of Defense and civilian.