bluuebunny/crossref_metadata_2025 huggingface dataset:
Interlayer and Design Considerations to Retard Reflective Cracking
Authors: Blankenship Phil , Iker Natalie , Drbohlav Joseph
Published: April 2007

To protect the structure and provide a new, smoother riding surface, many highway agencies overlay deteriorating portland cement concrete pavements with hot-mix asphalt (HMA) overlays. Reflective cracking through the overlays has been a persistent problem. Most methods that are used to delay the cracks have been based on tension (the horizontal movement occurring at the crack or joint interface). A performance-related flexural fatigue test addresses the tension, shear, and bending forces that result in reflective cracks. A reflective crack relief system consisting of an impermeable, highly elastic interlayer that uses fine-graded aggregates and a quality HMA overlay has been specified with flexural fatigue for crack resistance and Hveem stability for rutting resistance. Preliminary cracking data from several projects that used the specification and their control sections show that reflective cracking is delayed. Cores taken from the test sections show that even when the overlay cracks, the interlayer remains intact and impermeable, protecting the pavement structure from moisture intrusion. These cores also show that, unlike those in the control sections, the reflective cracks over the new system are offset from the underlying joints and further disrupt paths for water and giving better rideability. Seven state departments of transportation have used the performance-related specification for constructing the interlayer and overlay.
Accelerated Pavement Testing Evaluation of the Structural Contribution of Full-Depth Reclamation Material Stabilized with Foamed Asphalt
Authors: Romanoschi Stefan A. , Hossain Mustaque , Gisi Andrew , Heitzman Michael
Published: April 2007

Research was conducted to determine the effectiveness of the use of foamed asphalt-stabilized reclaimed asphalt pavement from full-depth reclamation (FAS-FDR) as base material for flexible pavements. The experiment, conducted at the Civil Engineering Infrastructure Systems Laboratory of Kansas State University, consisted of constructing four pavements—one with a 9-in. conventional Kansas AB-3 granular base and one each with 6, 9, and 12 in. of FAS-FDR—and subjecting them to a full-scale accelerated pavement test. All four pavement sections were loaded with 500,000 axle load repetitions, at room temperature and under moderate moisture levels in the subgrade soil. The measured stresses and strains as well as the permanent deformation (rutting) observed on the pavement sections indicated that FAS-FDR can be used successfully as a base material. The measured rut depths and compres-sive vertical stresses at the top of the subgrade suggest that a 1-in. FAS-FDR base shows performance equivalent to that of a 1-in. conventional Kansas AB-3 granular base. The effective structural number computed from the falling weight deflectometer tests on the as-constructed pavements showed that average structural layer coefficient for the FAS-FDR base material was 0.18.
One-Way and Two-Way Directional Heavy-Vehicle Simulator Loading: Effects on Rutting in Hot-Mix Asphalt Pavements
Authors: Novak Marc , Birgisson Bjorn , Roque Reynaldo , Choubane Bouzid
Published: April 2007

Instability rutting generally occurs within the top 5 cm (2 in.) of the asphalt layer when the structural properties of the asphalt concrete are inadequate to resist the stresses imposed on it. It is generally believed that near-surface transverse shear stresses perpetuate instability rutting. Field observations of heavy-vehicle simulator testing noted greater rutting in one-way directional loading than with two-way directional loading, even at lower temperatures and with longer rest periods between load applications. An analysis of stress states in the asphalt pavement layer using the three-dimensional finite element commercial code ADINA showed that longitudinal stress path patterns varied between the different directional loadings. A hypothesis was developed that the differences in longitudinal plane stress path patterns between one-way and two-way directional loading could be attributed to the different levels of rutting. A viscoelastic model with load applications simulating the different directional loadings was constructed and used to test this hypothesis. The viscoelastic model results indicated qualitatively that even with greater relaxation times, one-way directional loading produces greater strains.
Development of Accident Prediction Models for Rural Highway Intersections
Authors: Oh Jutaek , Washington Simon , Choi Keechoo
Published: April 2007

A study was done to develop macrolevel crash prediction models that can be used to understand and identify effective countermeasures for improving signalized highway intersections and multilane stop-controlled highway intersections in rural areas. Poisson and negative binomial regression models were fit to intersection crash data from Georgia, California, and Michigan. To assess the suitability of the models, several goodness-of-fit measures were computed. The statistical models were then used to shed light on the relationships between crash occurrence and traffic and geometric features of the rural signalized intersections. The results revealed that traffic flow variables significantly affected the overall safety performance of the intersections regardless of intersection type and that the geometric features of intersections varied across intersection type and also influenced crash type.
Study of Fatal Traffic Accidents in Asia Pacific Countries
Authors: Kumara S. S. P. , Chin H. C.
Published: April 2007

The traffic accident rates in many Asia Pacific countries are high, but little is known about how these rates are influenced by the social and developmental status of the countries. Identification of these factors is an essential task in prescription and prioritization of safety treatment programs so that proper planning and efficient budgeting can be implemented. The fixed-effect negative binomial model was used to examine the effect of socioeconomic and infrastructure factors on fatal road accidents in the Asia Pacific region. Making use of accident data from 1980 to 1994 for 41 countries in the region, the model shows that size of road network, per capita gross national product, population, and number of registered vehicles are important factors that increase accident occurrence. However, fatal accidents tend to decrease with time in all countries.
Effective and Fair Identification of Hazardous Locations
Authors: Tarko Andrew P. , Kanodia Mayank
Published: April 2007

The two fundamental objectives of a safety management system are to prevent as many crashes as possible and to reduce the difference in risk faced by individual road users. An index of crash frequency and an index of crash cost are proposed to address these two criteria in the hazard identification phase of safety management. An index of crash cost is used to incorporate severity in identification criteria. Safety performance functions based on negative binomial distribution are used to predict the typical crash frequency at the location. The proposed methods can be used to rank locations and to evaluate the degree of hazard at an individual location without referring to other locations. These methods determine the evidence of hazard at all types of locations (intersections and segments), and they can use crash data from periods shorter than 1 year. Indices of crash frequency and cost were evaluated and found helpful for safety management that reduces the number of crashes and risk variability across a road network.
Predicting Freeway Crashes from Loop Detector Data by Matched Case-Control Logistic Regression
Authors: Abdel-Aty Mohamed , Uddin Nizam , Pande Anurag , Abdalla M. Fathy , Hsia Liang
Published: April 2007

Growing concern over traffic safety has led to research into prediction of freeway crashes in an advanced traffic management and information systems environment. A crash likelihood prediction model was developed by using real-time traffic flow variables (measured through a series of underground sensors) potentially associated with crash occurrence. The issues related to real-time application, including range of stations and time slice duration to be examined, were also addressed. The methodology used, matched case-control logistic regression, was adopted from epidemiological studies in which every crash is a case and corresponding noncrashes act as controls. The 5-min average occupancy observed at the upstream station during the 5 to 10 min before the crash, along with the 5-min coefficient of variation in speed at the downstream station during the same time, was found to affect crash occurrence most significantly and hence was used to calculate the corresponding log-odds ratio. A threshold value for this ratio may then be set to determine whether the location must be flagged as a potential crash location. It was shown that by using 1.0 as the threshold for the log-odds ratio, more than 69% crash identification was achieved.
Safety Evaluation of Permanent Raised Snow-Plowable Pavement Markers
Authors: Persaud Bhagwant , Bahar Geni , Mollett Calvin J. , Lyon Craig
Published: April 2007

Permanent raised pavement markers (PRPMs) often are used to improve preview distances and guidance for drivers in inclement weather and low light conditions. However, studies in three states in the United States have raised concerns about these devices after negative safety effects were found. To address these concerns, an NCHRP project was initiated to assess definitively the safety effects of PRPMs and to develop guidelines for their implementation, by using state-of-the-art methodology and a database from across the United States. This project evaluated the safety performance of snow-plowable PRPMs on two-lane roadways and four-lane freeways by using data collected from five states. The results show that on two-lane roadways selective installations in one state were accompanied by highly significant decreases in total, nighttime, and wet-weather crashes, whereas there was no apparent overall safety benefit for the nonselective installations in two states. A disaggregate analysis of those results found that the nighttime crash effects can be larger on higher-volume roadways and those with degree of curvature of 3.5 or less (radius larger than 500 m). On four-lane freeways, there were some positive indications for wet-weather, guidance-related, and nighttime crashes, with the effects for nighttime crashes increasing as traffic volumes increased. The results of the disaggregate analysis were used to recommend Manual on Uniform Traffic Control Devices guidelines for the implementation of PRPMs.
Accommodating Heterogeneity and Heteroscedasticity in Intercity Travel Mode Choice Model: Formulation and Application to HoNam, South Korea, High-Speed Rail Demand Analysis
Authors: Lee Jang-Ho , Chon Kyung-Soo , Park ChangHo
Published: April 2007

Multinomial logit models and nested logit models are limited in that they cannot accommodate unobserved variations in travelers' taste and they do not have flexible substitution patterns among alternatives because of the independence of irrelevant alternatives property. Taking this background into account, traffic demand analysts have recently used the mixed logit model in many studies. Unfortunately, most of the studies in the literature for joint analysis of revealed-preference (RP) and stated-preference (SP) data could not simultaneously resolve the two limitations just mentioned. The mixed logit framework is used to formulate an intercity travel mode choice model for joint RP-SP analysis that accommodates the following behavioral considerations: ( a) observed and unobserved heterogeneity across individuals in response to level-of-service (LOS) factors, ( b) heteroscedasticity across alternatives, and ( c) scale differences between the RP and SP choice contexts. The mixed logit formulation is estimated with the maximum simulated likelihood method that employs quasi-random Halton draws. The formulation is applied to examine the travel behavior responses of users of the HoNam, South Korea, high-speed rail to changes in travel conditions. The empirical results show that there is a significant heteroscedasticity across alternatives and a significant heterogeneity in response to LOS attributes based on both observed and unobserved individual characteristics. There is an improvement in the data-fit statistics when one introduces heterogeneity and heteroscedasticity. These results highlight the need to include heterogeneity and heteroscedasticity within the context of intercity travel mode choice modeling to assist policy decision making.
Household Allocation Module of Oregon2 Model
Authors: Hunt John Douglas , Abraham John E. , Weidner Tara J.
Published: April 2007

The Oregon2 model is a set of seven integrated modules that together simulate the land use-transport system in the state of Oregon. One of these modules, called the household allocation module, updates the economic and demographic attributes of each person and household in a synthetic population, including age, sex, occupation, work and student status, job holdings, household membership, primary- and secondary-home size and location, income, and car ownership. It uses an agent-based microsimulation with Monte Carlo selection to identify choice outcomes and state transitions for each person or household concerning each economic or demographic attribute considered, with selection probabilities determined by using logit models and sampling distributions that are functions of relevant alternative attributes and household or person characteristics. Initial parameter values were estimated with data from Oregon household travel surveys, the University of Michigan Panel Survey of Income Dynamics, U.S. census data, and other published statistics. Spatial locations are represented in a system of roughly 3,000 geographic zones covering the study area. Six housing types, eight occupation categories, and continuous quantities for housing size and income are also represented. Housing markets are represented by using a disequilibrium structure, in which prices in each zone are updated in response to the vacancy rate relative to a reference rate, moving toward but not necessarily reaching a market-clearing solution.
Incremental Modeling Developments in Sacramento, California: Toward Advanced Integrated Land Use-Transport Model
Authors: Abraham John E. , Garry Gordon R. , Hunt John Douglas , Brownlee Alan T.
Published: April 2007

The regional transportation planning agency in Sacramento, California, is taking a three-pronged approach to updating its land use-transportation forecasting models: developing a long-term model design, improving existing models toward that design, and collecting data that can be used to support the existing models while the new design is being developed. The advanced integrated model design contains a tour-based travel model involving microsimulation of individual tours of synthetic households, a microsimulation-based land development model, and a spatial input-output model of the regional economy. The existing models consist of a land use model based on the MEPLAN model, a traditional four-step model of transportation demand improved with the addition of an automobile ownership submodel and joint consideration of mode and destination for work trips, and an interactive neighborhood-level parcel allocation system. The process described is one of improvement of current models and of moving toward a new model design while the agency faces ongoing modeling needs and uncertain budgets.
Dynamics of On-Street Parking in Large Central Cities
Authors: De Cerreño Allison L. C.
Published: April 2007

Parking is a critical component of transportation policy and management, especially for large central cities. Policies and management practices affecting parking in turn affect land use, air quality, traffic congestion, travel behavior, safety, economic development, and revenue. Yet effectively managing parking is an ongoing struggle for large central cities as they face competing objectives and ever-increasing demands for space. As important as parking is, relatively few serious analyses of parking exist, and even fewer of on-street or curb parking, which is of particular interest to central cities. FHWA funded a year-long study that included an extensive literature review, one-on-one discussions with city parking officials, a peer-to-peer exchange, and a questionnaire to which nine U.S. cities responded. The study was intended to describe comprehensively on-street parking policies and management practices in large cities and to identify best practices and areas for further research. Lessons learned include the following: to manage effectively, one must know what is being managed, yet many cities lack basic information about their parking resources; integration and coordination among agencies and divisions that manage parking is critical; and ongoing peer exchanges allow important information sharing to occur between cities.
Influence of Land Use on Travel Behavior in Santiago, Chile
Authors: Zegras P. Christopher
Published: April 2007

In an attempt to expand the research base on the land use-transport link in the developing world, a microeconomic model developed in the industrialized world context is adopted. The analysis focuses on the influence of three gross measures of urban form on travel behavior in Santiago, Chile. Controlling for socioeconomic and demographic factors, the analysis attempts to demonstrate the influence of population density, relative share of commercial and service land uses, and relative share of vacant land on an individual's propensity to make home-based, nonwork, non-school (HB NWNS) walking trips. Consistent with intuition, the model results suggest that the relative share of land devoted to commercial and service uses in the zone of trip origin increases the likelihood of making HB NWNS walking trips, whereas the relative share of vacant land decreases the probability. Somewhat surprisingly, population density in the zone of origin has no significant effect.
Toward a Strategy for Cost-Effective Deployment of Advanced Traveler Information Systems
Authors: Toppen Alan , Jung Soojung , Shah Vaishali , Wunderlich Karl
Published: April 2007

The effects of advanced traveler information system (ATIS) accuracy and the extent of ATIS roadway instrumentation on the on-time reliability benefits to routine users of ATISs were evaluated by using archived estimates of roadway travel times to re-create hypothetical, retrospective paired driving trials between travelers with and without ATISs. Previous research using this technique demonstrated that travelers who received notification of congestion before departure could realize time management benefits from improved on-time reliability and trip predictability. On the basis of millions of hypothetical trips over a 12-month period in Los Angeles, California, it was found that a net benefit to an average user of ATIS existed if the error in travel time estimation was in the range of 14% to 21% or better, a threshold that depended on regional day-to-day travel time variability. For less accurate ATIS services, only certain subsets of the driving population, such as those with relatively long or highly variable trips, may realize any benefit. Furthermore, it was observed that a nearly optimal geographical deployment of ATIS could garner as much as 56% of the benefit of full coverage from the first 30% of deployment. Yet, the best deployment strategy is not as simple as prioritizing links on the basis of day-to-day variability. In making cost-effective trade-off decisions about how to invest in improved ATISs, be it expanding geographic coverage or improving accuracy, the findings underscore the importance of understanding the accuracy required to generate ATIS user benefits on the basis of regional day-to-day roadway variability.
Usability of Statewide Web-Based Roadway Weather Information System
Authors: Fayish Aaron C. , Jovanis Paul P.
Published: April 2007

A study of the usability of statewide web-based traveler information systems was conducted to assess their effectiveness in conveying road and weather information to travelers. Guidelines from traveler information systems and the website design literature were coalesced to create an assessment framework to include important elements from a user’s perspective. Ninety-eight travelers from the State College, Pennsylvania, area visited web-based roadway weather information systems for Pennsylvania, Maryland, and Ohio as part of a laboratory-based trip-planning experiment and provided ratings of site attributes. Site ratings revealed that it was important that travelers accessed information about conditions along their intended route with minimal searching. Map scale and resolution were important graphical elements. The most relevant weather information elements identified by users were precipitation type, road surface condition, visibility, and air temperature.
In-Vehicle Alerting System for Older and Younger Drivers: Does Experience Count?
Authors: Maltz Masha , Sun Hongyan , Wu Qiong , Mourant Ronald
Published: April 2007

Experienced older drivers and relatively inexperienced younger drivers drove a simulator equipped with a headway detection and alerting device (HDAD). The device alerted the driver when the time headway (TH) to the lead car was too short. The device occasionally emitted false alarms on the basis of a predefined reliability level. The HDAD was not activated for the control group. The experimental groups that drove with the HDAD maintained a TH within an “optimal” zone (2 s ≤ TH ≤ 4 s) during significantly more of the driving time than the control group. Drivers who used the HDAD discriminated between true alerts and false alarms and responded more often to true alerts. All groups maintained, on average, a safe headway (>2 s). Although the average time in the danger zone was different for the younger and the older drivers, the variance within both groups, especially within the older driver group, was large and neutralized the difference. When the reliability of HDAD was the highest (99%), the driver’s headway was shorter, although it was still well within the safe range. This could indicate increased confidence inspired by a very reliable device. Although multiple auditory stimuli were clearly defined during the experiment, they still caused confusion, especially for the older drivers, and may have hindered better performance. The results associate conflicting auditory signals as possible deterrents to the effective use of in-car aids for older drivers who may have trouble dividing attention among the inputs. Suggestions are given as to how in-car driver-aid interfaces can be improved for older drivers.
Vehicle Height Affects Drivers’ Speed Perception: Implications for Rollover Risk
Authors: Rudin-Brown Christina M.
Published: April 2007

The North American vehicle fleet has evolved in recent years to include an increasing percentage of pickups, sport utility vehicles (SUVs), and minivans. In 2002, sales of light trucks and vans accounted for almost half of all Canadian vehicle sales. The increased popularity of SUVs has been particularly striking, with a 143% increase in sales since 1993. Typically larger and heavier than automobiles, SUVs are built on frames that are more rigid and that ride higher, characteristics that not only provide increased physical protection to their occupants but also add to their overall appeal. SUVs, however, are involved in fatal rollover crashes at a much higher rate than cars. While this is undoubtedly due in part to their stiffer frames and higher centers of gravity, the manner in which SUVs are driven may also play a role. SUV drivers are often anecdotally reported to be overconfident, tending to overestimate their vehicle’s capabilities. Evidence suggests that because they sit higher, drivers of SUVs (and vans and pickups) are less able to judge speed accurately. A study was conducted to assess drivers’ chosen speed when they operated a simulated vehicle while viewing the road from a low eye height and a high eye height. Participants were instructed to drive, without reference to a speedometer, at a highway driving speed at which they felt comfortable and safe. As expected, drivers seated at a high eye height drove faster than when they were seated at a low eye height. The influence of driver eye height and lead vehicle size (large versus small) on the following distance from a slower-moving lead vehicle was also investigated. Regardless of eye height, the differences in following distances suggest that the size of the lead vehicle may affect how closely drivers choose to follow it.
Route-Following and Safety Errors by Drivers with Stroke
Authors: Uc Ergun Y. , Rizzo Matthew , Anderson Steven , Shi Qian , Dawson Jeffrey
Published: April 2007

Navigating a newly learned route is one of the multiple tasks during automobile driving that competes for a driver’s cognitive resources. Stroke, a frequent cause of focal brain damage and cognitive dysfunction, has the potential to impair driving, especially when multitasking is required. The navigational abilities and driving safety errors of stroke patients (in the chronic phase of maximal recovery) were compared with those of healthy control subjects in a route-following task with an instrumented car. All subjects were legally licensed active drivers, and participation was voluntary. All drivers participated in an off-road battery of visual and cognitive tests of abilities that were critical to safe automobile driving. At the onset of the navigational task, each subject was required to recite and learn correctly a brief set of verbal directions to a destination. The main outcome measures were the number of ( a) incorrect turns, ( b) times lost, and ( c) at-fault safety errors during the task. The drivers with stroke made significantly more incorrect turns, got lost more often, and made more at-fault safety errors than the neurologically healthy controls. These significant differences persisted for all outcomes except for getting lost after statistical adjustments for familiarity with the neighborhood. The navigational and at-fault safety errors were predicted by scores on standardized off-road tests sensitive to visual and cognitive declines in drivers with stroke. Drivers with stroke made more navigational and safety errors than neurologically healthy drivers on a route-following task that placed demands on driver memory, attention, and perception. The demands of following route directions probably increased the cognitive load during driving, which may explain the higher number of safety errors.
Visual Information for Car Following by Drivers: Role of Scene Information
Authors: Andersen George J. , Sauer Craig , Saidpour Asad
Published: April 2007

An important task during driving is the maintenance of headway during car following. The visual information available to a driver for successful car following was examined. A model of car following that used the visual angle and change in visual angle of a lead vehicle was developed. The study examined whether information from the surrounding scene (e.g., the roadway and buildings) influenced car-following performance. Licensed drivers were presented with a car-following task in a driving simulator. The simulator display consisted of a roadway scene with a lead vehicle that varied speed according to a sine wave. To evaluate the role of scene information, car-following performance was examined when the surrounding scene was present or absent. Two frequencies and three amplitudes of speed variation were also examined. The results indicated that control gain was greater when the scene was absent, with near unity gain when the scene was present. These findings indicated more accurate control during car following when the surrounding scene information was present. These results suggest that drivers also use other sources of information (e.g., absolute distance information from height in the visual field relative to the horizon and edge rate information specifying observer speed) to maintain headway. The implications of this research to nighttime accident rates and intelligent highway systems are discussed.
Organizational Competence in Strategic Safety Management: Self-Assessment in U.K. Rail Industry
Authors: Johnson Charles , Nelson Aidan
Published: April 2007

Competence Assurance Solutions Ltd. (CAS) produced the Good Practice Guide in 2000, the first version of Railway Safety’s Good Practice Guides for strategic safety management. The guides and accompanying software contain a self-assessment process that enables the top management teams of railway companies to determine whether the team and the organization are sufficiently competent to discharge their strategic safety management responsibilities. To support the Good Practice Guides, CAS provides, on behalf of the Rail Safety and Standards Board (which succeeded Railway Safety on April 1, 2003), a mentoring process to guide top management teams through the self-assessment process. The findings and conclusions from the ongoing mentoring process are presented. At present, 27 leading U.K. rail companies are being mentored. They are in different stages of the process, although many have completed a self-assessment in all four of the key strategic areas considered: policy and strategy, risk assessment and control, organizational resourcing and support, and operational control. Already, a pattern has emerged among those companies that have completed the assessment. Almost all consider themselves stronger in the areas of strategy and policy and operational control and weaker in the areas of risk control and resourcing and support. The weaknesses are particularly marked for human factors. Furthermore, companies differ significantly in their self-ratings, with these differences being reflected in some aspects of safety performance. Consideration is given to the safety issues that dominate the minds of senior teams, their areas of strength and weakness, the characteristics of high- and low-scoring companies, and the sources of unrealistic self-assessments.
Impacts of Participatory Safety Rules Revision in U.S. Railroad Industry: An Exploratory Assessment
Authors: Ranney Joyce , Nelson Christopher
Published: April 2007

Increasingly, the proliferation of safety rules is viewed not just as a nuisance but also as a threat to safety itself. Indeed, voluminous and overlapping rules might contribute to poor compliance because of confusion and disagreement about which rules are to be followed. When combined with the existing regime of fault-based injury liability laws governing the industry, rules often become the focus of worker–management conflict rather than tools for communication about safety hazards and solutions. An exploratory assessment of participatory rules revision as an instrument of safety improvement in the U.S. railroad industry is presented. A key premise of the intervention is that rules proliferation is symptomatic of deeper problems with the organizational safety culture that can be addressed through extensive stakeholder participation in the revision process. Data for the study came from three railroads and one in-land barge line. While interview data provided evidence for an impact on the safety culture, initial statistical analysis of the incident data failed to find decreases in incident rates associated with the advent of the formal rules revision process. Further exploration, however, suggested that the intervention actually began earlier with various preparatory activities. Statistical analysis of this revised hypothesis found a significant impact of the intervention on incident rates at one rail carrier, while incident rate declines at two other carriers could not be attributed to the intervention with confidence.
Visualization in Transportation: Current Practice and Future Directions
Authors: Hughes Ronald
Published: April 2007

The use of computer image generation technologies within the transportation field to aid both the design and the user communities to visualize better the essential elements of a proposed facility’s structure as well as its operation is addressed. The primary focus is on current and future applications of these technologies and their integration within the overall notion of context-sensitive design and public involvement. The discussion suggests that a movement away from the visualization of what something looks like to the visualization of how something works or operates is being encountered, a trend that forces the integration of modeling and simulation. The discussion also suggests the importance of applications that use visualization to help bridge the gap between notions of design and notions of value. Such applications also reflect an increased integration of design-oriented applications and planning-oriented applications, such as those that incorporate the use of spatially referenced data systems such as geographic information systems.
Visualizing Massive Terrain with Transportation Infrastructure by Using Continuous Level of Detail
Authors: Huang Bo , Li Hongga , Huang Xiaoxia
Published: April 2007

An approach to the efficient rendering of terrain surfaces through the use of continuous level of detail but with maintenance of the integrity of added transportation features such as roads, bridges, railways, bus stops, and traffic lights is explored. A quadtree structure was developed to define the terrain surface as a gridded height field and, in the rendering process, to project transportation features in three dimensions onto the terrain surface on the fly. Also, with the viewpoint moving, the connected strips and fans between transportation features and terrain meshes were dynamically adjusted to reduce the projected pixel error. Consequently, the massive terrain and transportation features can be visualized simultaneously in an efficient way. This approach is illustrated with several snapshots, and the efficiency of the algorithms is also demonstrated.
Assessment of Profiler Performance for Construction Quality Control with Simulated Profilograph Index
Authors: Karamihas Steven M.
Published: April 2007

The simulated California profilograph index (PI) values produced by repeat measurements from 11 profiling devices on four pavement sections are examined. Repeatability and reproducibility of simulated PI by common profiling devices are discussed, and automated profilograph trace reduction procedures adopted in profilograph simulations are reviewed. The results of profilograph simulations show that the low-pass filter and minimum scallop width are important aspects of trace reduction and should be retained as standard components of simulated profilograph trace reduction. However, criteria are needed to help remove narrow, downward spikes, such as those found in profiles of jointed concrete. The results also show that existing profilers do not agree on PI values sufficiently when a zero blanking band is used.
Effect of Material Transfer Devices on Flexible Pavement Smoothness
Authors: Harris Jennifer Kristy , Parker Frazier , Stroup-Gardiner Mary
Published: April 2007

The initial smoothness of a pavement is linked to both future pavement smoothness and pavement life. Research was conducted to study the effects of adding a material transfer device to the paving train. The focus was to determine if the use of a material transfer device improved flexible pavement smoothness. An automated data collection van was used to collect pavement profile data, and smoothness was quantified with the international roughness index in inches per mile. An infrared camera and a rolling wheel were used to detect and locate portions of the mat with temperature differences of more than 10°C (19°F). It was found that a material transfer device significantly improved flexible pavement smoothness. Fewer areas with temperature differences of more than 10°C were noted when a material transfer device was used, and areas with these temperature differences were found to be significantly rougher than locations that had more uniform temperatures. In an additional finding, unrelated to the use of a material transfer device, the extension of the screed to one side of the paver caused a significant increase in roughness in the wheelpath on that side.
Maturity Method Applied to Highway Construction
Authors: Mohsen J. P. , Roach Bernard L. , Kessinger Dav T.
Published: April 2007

The use of the maturity method in concrete pavement construction is becoming popular for state departments of transportation (DOTs). An application of the technique is the opening of pavements to traffic. Research was done by the Kentucky DOT to identify the viability of this method. The application of the maturity technique to three fast-track concrete pavement repair projects is outlined. The chosen equipment, preferred instrumentation methodology, and lessons learned by department personnel are summarized. The results obtained to date show that the maturity approach can be used effectively in quality control and opening to traffic. However, close attention should be given to the limitations of the technique.
Life-Cycle Cost Analysis-Embedded Monte Carlo Approach for Modeling Pay Adjustment at State Departments of Transportation
Authors: Choi Jae-Ho , Bahia Hussain U.
Published: April 2007

The development of a pay-adjustment procedure for implementing performance-related specifications is a difficult task for most state highway agencies because of such problem areas as selecting pay-factor items, modeling the relationship between stochastic variability of pay-factor items and pavement performance, and determining an overall lot pay adjustment. An effective way to develop a scientific pay-adjustment procedure by incorporating the life-cycle cost analysis–embedded Monte Carlo simulation (LMCS) approach was needed. Presented is an application to a real project to determine a pay adjustment by using the data in the pavement management information systems at the Wisconsin Department of Transportation as an exemplary to other state highway agencies. It was concluded that the proposed LMCS approach can effectively model an overall pay adjustment by considering both the inherent variability in pay-factor items and the interactions among individual pay-adjustment schedules. A sensitivity analysis was conducted to determine the relative importance of pay-factor items and to validate the application of the LMCS approach.
Innovative Strategies on Dallas High Five Project
Authors: Khwaja Nabeel , Nelson Jay
Published: April 2007

The $262.9 million Dallas High Five project is reconstructing the busiest freeway interchange in the largest metropolitan area in Texas. The five-level, fully directional interchange between US-75 (North Central Expressway) and I-635 (Lyndon B. Johnson Freeway) is being reconstructed to replace the existing three-level partial cloverleaf interchange built in the mid-1960s. It was the single largest contract ever let by the Texas Department of Transportation and was more than double the previous largest contract. The project site is in the middle of a highly developed commercial zone of the city and poses all the challenges associated with urban freeway reconstruction. Almost 500,000 vehicles pass through the construction site every day, and extraordinary care was taken to minimize the impact on traffic and abutting businesses by instituting innovative strategies in the construction contract, including lane rental, windowed milestones, and no-excuse incentives. The financing concept adopted for this project has since become a statewide criterion. Details about contracting strategies and the thought processes involved in their development and application are presented, along with results from their application so far.
Trajectories and predictors of indirect aggression: results from a nationally representative longitudinal study of Canadian children aged 2–10
Authors: Vaillancourt Tracy , Miller Jessie L. , Fagbemi Joshua , Côté Sylvana , Tremblay Richard E.
Published: April 2007

The purposes of this study were to model the development of indirect aggression among a nationally representative sample of 1,401 Canadian children aged 4 at T2, 6 at T3, 8 at T4 and 10 at T5, and to examine predictors of trajectory group membership from T1 (age 2) child, familial, and parenting variables. Using a semi‐parametric group‐based modeling approach, two distinct trajectories were identified: “increasing users” comprising of 35% of the sample and “stable low users” comprising of 65% of the sample. Using logistic regression analyses to distinguish these two groups, we found that for girls, more frequent, increasing use of indirect aggression was associated with prior prosocial and physically aggressive behavior, low SES and low parental social support at age 2. For boys, increasing use of indirect aggression was associated with prior parenting issues at age 2—inconsistency and less positive parent–child interactions. Although this study provides unique information regarding the early development of indirect aggression and its predictors, more longitudinal research is needed to fully understand its development. Aggr. Behav. 33:314–326, 2007. © 2007 Wiley‐Liss, Inc.
The alcohol–aggression link: children's aggression expectancies in marital arguments as a function of the sobriety or intoxication of the arguing couple
Authors: El‐Sheikh Mona , Elmore‐Staton Lori
Published: April 2007

Children's expectancies of man–woman and woman–man aggression during arguments between individuals who were either intoxicated or sober were examined. The role of child and familial characteristics in influencing these expectancies was assessed. We examined children's expectations of interadult verbal/psychological and physical aggression during simulated arguments presented to children on videotapes. A community sample (N = 156) of children and young adolescents (6–14‐year olds) participated. Children expected higher levels of aggression during conflict when they thought that one or both participants in conflict were intoxicated versus sober. Further, higher levels of verbal versus physical interadult conflict were expected during the disputes. These findings build on the literature by demonstrating that elementary school age children and young adolescents exhibit expectancies that link the consumption of alcohol with increased verbal and physical aggression in marital arguments. These alcohol–aggression expectancies were robust and were evident in relation to either the man's or woman's perpetration of aggression against the spouse. Elucidation of factors that can influence associations between aggression and alcohol consumption are of importance and have broad implications for family functioning. Aggr. Behav. 33:458–466, 2007. © 2007 Wiley‐Liss, Inc.
Optimal design of batch‐storage network considering exchange rates and taxes
Authors: Yi Gyeongbeom , Reklaitis Gintaras V.
Published: April 2007

This article presents an integrated analysis of the supply chain and financing decisions of multinational corporations. We construct a model in which multiple currency storage units are installed to manage the currency flows associated with multinational supply chain activities such as raw material procurement, processing, inventory control, transportation, and finished product sales. Temporary financial investments, bank loans, and currency transfer between multiple nations are allowed to increase the marginal profit. The core contribution of this study is its quantitative investigation of the influence of macroscopic economic factors such as exchange rates and taxes on operational decisions. The supply chain is modeled as a batch‐storage network with recycling streams. The objective function of the optimization involves minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders in the numeraire currency. The major constraints of the optimization are that the material and currency storage units must not be depleted. A production and inventory analysis formulation (the periodic square wave model) provides useful expressions for the upper and lower bounds and average levels of the currency and material inventory holdings. The expressions for the Kuhn‐Tucker conditions of the optimization problem are reduced to a subproblem and analytical lot‐sizing equations. The lot sizes of procurement, production, transportation, and financial transaction can be determined by analytical expressions once the average flow rates are known. We show that the optimal production lot and storage sizes are typically 20% smaller when corporate income tax is taken into consideration than when it is not considered. An illustrative example is presented to demonstrate the potential of this approach. © 2007 American Institute of Chemical Engineers AIChE J, 2007
ADR v. the Bench: Why are neutrality standards different?
Authors: Meyer Judith P.
Published: April 2007

Judith P. Meyer, of Haverford, Pa., discusses the intersection of judges' courtroom roles and arbitrator disclosure, and how they affect perceptions of fairness, in the first of two parts highlighting ADR ethical considerations
Key ADR Web domains are in play—at a steep price
Authors: Bleemer Russ
Published: April 2007

The reaction over Supreme Court Justice Anthony Kennedy's calling out ADR Provider JAMS at a Senate Judiciary Committee hearing, and the details behind this month's sale of arbitration.com and mediation.com
Cover Picture: Nitrogen–Carbon Bond Formation from N2 and CO2 Promoted by a Hafnocene Dinitrogen Complex Yields a Substituted Hydrazine (Angew. Chem. Int. Ed. 16/2007)
Authors: Bernskoetter Wesley H. , Lobkovsky Emil , Chirik Paul J.
Published: April 2007

Two typically inert molecules, dinitrogen and carbon dioxide, are activated and combined, with the formation of carbon–nitrogen bonds, using a bis(cyclopentadienyl) hafnium compound. The resulting silyl‐protected carboxy‐hydrazine (central structure) is liberated from the complex upon treatment with the electrophile Me3SiI, as illustrated in the cover picture. For more information on this reaction, see the Communication by P. J. Chirik and co‐workers on page 2858 ff.
Inside Cover: O‐Glycoside Orientation Is an Essential Aspect of Base J Recognition by the Kinetoplastid DNA‐Binding Protein JBP1 (Angew. Chem. Int. Ed. 16/2007)
Authors: Grover Rajesh K. , Pond Stephanie J. K. , Cui Qizhi , Subramaniam Prem , Case David A. , Millar David P. , Wentworth Paul
Published: April 2007

Protein recognition of DNA is key to the control of genome expression within living cells. Kinetoplastid parasites like those in the background possess the protein JBP1, which binds to double‐stranded DNA containing the glycosylated base shown (nucleoside dJ). In their Communication on page 2839 ff., P. Wentworth, Jr. et al. analyze the binding and find that JBP1 recognizes a critical edge‐on conformation of the pyranosyl ring of nucleoside dJ. These results are important for the development of new biological targets for antiparasitic drugs.