bluuebunny/crossref_metadata_2025 huggingface dataset:
Prototype Testing of Intelligent Stiffener for Bridges at I-35 Walnut Creek Bridge
Authors: Patten William Neff , Sun Jinghui , Song Gang
Published: April 2007

There is an evident need to develop technologies to extend the useful life of bridges. A recent report to the U.S. Congress indicates that approximately 25 percent of U.S. bridges are rated as deficient, with an estimated cost of $7 billion per year for the next 26 years to rebuild or replace those bridges. The Center for Structural Control at the University of Oklahoma has been engaged in a multiyear effort to develop smart technologies that extend the useful service life of bridges. The research effort has culminated in the development of an intelligent stiffener for bridges (ISB) that can be retrofitted to an existing bridge. Results indicate that the ISB system can add decades of service life to an existing bridge. The ISB consists of an otherwise generic stiffener retrofitted to a bridge. The stiffener is unique in that it is equipped with an adjustable hydraulic link that is used to regulate the amount of stiffness (and damping) provided by the stiffener as vehicles pass over the bridge, acting much like a muscle, sometimes flexed and other times relaxed. The ISB is referred to as a semiactive control system because it uses no line power and is energized by a 12-volt automobile battery. This paper reports the first successful demonstration of the ISB technology on an in-service bridge. Discussed are the ISB design features, the steps used to establish a reduced-order finite element model of the bridge, and a brief description of the procedures used to validate the bridge model.
Influence of Bridge Approach, Surface Condition, and Velocity on Impact Factors for Fatigue-Prone Details
Authors: Clarke Shima Najem , Deatherage J. Harold , Goodpasture David W. , Burdette Edwin G.
Published: April 2007

An impact study on a long-span continuous highway steel girder bridge is described. Crawl and full-speed test data were analyzed to examine the influence of bridge approach, surface condition, and truck velocity on impact factors for fatigue-prone details in both main and secondary bridge members. The measured impact factors for fatigue stress categories A, B, E, and E’ details were compared with values obtained using the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications formula. For fatigue-prone details, the test results showed that surface roughness, truck velocity, and bridge approach affect the impact factor. Measured impact factors varied with the location of the detail. Also, the study showed that the AASHTO design impact factors were unconservative for details located in the bridge approach or end span.
Impact of 44 000-kg (97,000-lb) Six-Axle Semitrailer Trucks on Bridges on Rural and Urban U.S. Interstate System
Authors: Weissmann José , Harrison Rob
Published: April 2007

The impact of a 44 000-kg (97,000-lb) tridem semitrailer truck on bridges on the urban and rural U.S. Interstate system is examined. The impacts are determined using a suite of models developed for FHWA policy use, and both agency and user costs are estimated. Bridges on the Interstate system that are already deficient at current loads are excluded from this analysis, which utilizes the National Bridge Inventory database and reports results for the rural and urban Interstate systems.
Structural Performance of Buried Profile-Wall High-Density Polyethylene Pipe and Influence of Pipe Wall Geometry
Authors: Moser A. P.
Published: April 2007

Tests conducted on buried high-density polyethylene pipes are reported. Pipes were loaded until buckling occurred to determine performance limits and the influence of profile parameters on structural performance. These profile parameters include rib height, rib spacing, wall thicknesses, wall area per unit length, unsupported profile section length, and stiffness. In a profile-wall pipe, by design, as much pipe material as possible is placed away from the neutral axis in the form of inside or outside walls or in ribs to minimize the use of pipe material by increasing the section modulus of the pipe wall. For the products tested, the data show that the profile section acts as a unit as designed only up to a point. High earth loads will induce buckling in the profile wall of the pipe. For adequate safety, the pipe design should include sufficient plastic between the inner and outer walls or between the ribs to carry shear and to ensure that the profile section indeed acts as a unit. Each product exhibits different performance limits, and these limits occur at different loads and deflections. Performance limits are often deflection related, but for high soil densities they are load related. For profile-wall pipe, localized or general buckling is usually the lowest performance limit. The cross-sectional area per unit length and the individual wall component thickness should be sufficient to resist localized buckling. It should be noted that for some profile-wall pipes, controlling vertical deflection may not control localized buckling as a performance limit. Performance limits for the pipes tested are reported.
Nonlinear Finite Element Analysis for Thermoplastic Pipes
Authors: Zhang Chuntao , Moore Ian D.
Published: April 2007

Thermoplastic pipes are being used increasingly for water supply lines, storm sewers, and leachate collection systems in landfills. To facilitate limit states design for buried polymer pipes, nonlinear constitutive models have recently been developed to characterize the highly nonlinear and time-dependent material behavior of high-density polyethylene (HDPE). These models have been implemented in a finite element program to permit structural analysis for buried HDPE pipes and to provide information regarding performance limits of the structures. Predictions of HDPE pipe response under parallel plate loading and hoop compression in a soil cell are reported and compared with pipe response measured in laboratory tests. Effects on the structural performance of pipe material nonlinearity, geometrical nonlinearity, and backfill soil properties were investigated. Good correlations were found between the finite element predictions and the experimental measurements. The models can be used to predict pipe response under many different load histories (not just relaxation or creep). Work is ongoing to develop nonlinear constitutive models for polyvinylchloride and polypropylene to extend the predictive capability of the finite element model to these materials.
Laboratory Determination of Soil Stiffness Data for Buried Plastic Pipes
Authors: Faragher E. , Rogers C. D. F. , Fleming P. R.
Published: April 2007

The structural behavior of a buried flexible pipe is influenced by the applied surface loading, the pipe ring stiffness, and the stiffness of the surrounding soil. The pipe stiffness is governed by national standards and can be determined by testing. The more dominant surround stiffness depends on the soil type and its placement and is consequently greatly influenced by site installation processes. There is a relative lack of soil stiffness data, and much of the available data relates to more common installation conditions in the United States (i.e., installation beneath embankments). Described in this paper is the assessment of stiffnesses of surround types used in the United Kingdom by laboratory testing of plastic pipes in a large test tank to simulate burial in a trench. Both gravel and sand surrounds were used, and either thorough or nominal compaction was applied. Static surface stresses were then applied to the buried pipes and diametral strains recorded, which are used for back-analysis of Spangler’s modulus of soil reaction ( E’). The analysis yielded significantly higher values of E’ than have previously been assumed. For a lightly compacted sand, E’ was found to be 16 MPa. However, when the same sand was thoroughly compacted, E’ was found to be 99 Mpa. For a rounded, 10-mm gravel with only nominal (i.e., light) compaction, E’ was found to be 29 MPa. Where an existing pipe is subjected to an additional surface loading, the corresponding recommend E’ values for additional diametral strain prediction are 20, 100 to 150, and 40 MPa, respectively. The results obtained are discussed in relation to currently used values of E’ and site practice.
Laboratory Facility for Testing Road Iron work Installations
Authors: Brown S. F. , Brown C. J.
Published: April 2007

The term “road ironwork” is used to refer to covers that are placed over manholes, drainage gullies, water valves, and the like. Such ironwork can be found in virtually all highways, especially in urban areas. Highway engineers have to deal with a high incidence of premature failure in these installations, the total costs of which are estimated to be £207 million (U.S. $338 million 1998) per year in the United Kingdom alone. These failures are generally characterized by gradual deterioration of the surrounding asphalt surfacing, associated with failure of the bedding material that supports the ironwork frame. The reasons for this high incidence of failure were investigated in a research project involving the construction of a full-scale laboratory test facility to simulate field conditions. This paper contains a description of the development of this apparatus. The results recorded from the apparatus were later used to identify the failure mechanisms that develop within road ironwork installations.
Traffic Count Estimates for Short-Term Traffic Monitoring Sites: Simulation Study
Authors: Hu Patricia S. , Wright Tommy , Esteve Tony
Published: April 2007

Traffic characteristics, such as the annual average daily traffic (AADT) and the AADT for each vehicle class, are essential for highway maintenance and planning. In practice, selected road segments are monitored continuously every day of the year to identify their traffic characteristics. A sample of the remaining road segments is monitored for 1 or 2 d each year, and the resulting data are adjusted (by using factors based on data collected from the continuously monitored road segments) to produce estimates of annual average daily traffic characteristics. A simulation study empirically considered how the precision of an estimate from a continuously monitored site compares with the precision of an estimate from a short-term monitored site. The original estimates of traffic characteristics (i.e., AADT and AADT by vehicle class) treating the site as a continuously monitored site are on average quite close to, but smaller than, the simulated estimates treating the site as a short-term monitored site. The original estimates (continuous monitoring) appear to be more precise, on average, than the simulated estimates (short-term monitoring). This decrease in precision typically occurs for vehicle classes that account for less than 1 percent of the daily traffic volume, suggesting that these less-common vehicle classes could be combined to achieve reliable AADT estimates.
Precision and Bias of Data from Film
Authors: Gramling Wade L. , Miller John S. , Bellinger William Y.
Published: April 2007

An objective of the Long-Term Pavement Performance study is the development of improved pavement design procedures. This objective depends on performance data being collected on present in-service pavements. The primary pavement distress data collection was done by recording 35mm film images at intervals since 1988. Five rounds of images have been collected. The accuracy and repeatability of distress data collection was of concern. The effort to assess the quality of distress data resulting from analysis of 35mm pavement images is reported. A set of 12 pavement sections, including asphalt surface, jointed and continuously reinforced concrete, was digitized three times by 10 operators with various skill levels at intervals of several weeks between passes. The distress analysis was done by using four semiautomated computerized workstations to view a projected image of the pavement on a digitizing tablet with the operator using a cursor to input distress type, severity, and location. A data summary and plot were output from the software. The results of each digitizing pass were used to evaluate the repeatability of the operators, and grouped data were used to evaluate accuracy.
Development of Trip Production Rates for Synthesized Households
Authors: Scobee Shari P. , DuRoss Michael , Ratledge Edward C.
Published: April 2007

Survey nonresponse bias is an important consideration in the development of survey designs for transportation studies. Researchers at the University of Delaware have developed a technique for reducing the survey nonresponse, as well as the cost of the travel survey. The method involves obtaining complete household and person characteristics for each household member; however, detailed travel data are gathered for only one randomly selected household member. Although the University of Delaware survey technique provides multiple benefits with respect to survey response rates and costs, it presents complications for travel model developers, particularly with respect to the development of trip production models. Because the trip production models are typically developed at the household level, the person-level trip rates from such a survey need to be expanded to represent a household’s trip rates. A method is presented for generating synthesized household trip production rates by using the 1995/96 Delaware Household Travel Survey, which gathered travel information for only one household member.
Choosing a Household Survey Method: Results of Dallas—Fort Worth Pretest
Authors: Goldenberg Leslie
Published: April 2007

Presented are the findings of a pretest of a travel behavior survey conducted in the Dallas—Fort Worth region. The pretest directly compared five methodological options: ( a) a 24-h versus 48-h diary period; ( b) a shorter versus longer series of questions about each activity recorded; ( c) three types of incentives to encourage response; ( d) a booklet versus log format for the diaries; and ( e) telephone versus mailback retrieval of information. A diary recording period of 24 h was 1.6 times more likely to result in a completed household survey response than a 48-h recording period ( p-value <0.01). Telephone retrieval was twice as likely to result in a completed household than through mailbacks ( p-value <0.01). There was a significant difference ( p <.01) in the mean number of trips per day per person for those retrieved by telephone and mailback. Households with a 24-h recording period responded with significantly more trips per day per person (4.7) than households with a 48-h period (3.9) ( p <.01). Considering separately the trip rate on each of the 2 d that made up a 48-h reporting interval, the mean number of trips per day per person showed a statistically significant trend ( p <.01) toward fewer trips on the second day (mean difference of 0.6 fewer trips compared with the first day).
Obtaining Travel Intensity Profiles from Household Travel Survey Data
Authors: Roddis S.M. , Richardson A.J. , Mcpherson C.D.
Published: April 2007

Innovative ways to examine the spatiotemporal variations in road traffic, by using data from the Victorian Activity and Travel Survey (VATS), are presented. The approach is shown to offer significant advantages over traditional methods of analysis, such as observational surveys or roadside traffic counts. By linking the complete vehicle travel paths reported in VATS with the detailed demographic data of the respondents, a comprehensive understanding of travel and driver behavior is developed. The general methodology described is shown to be applicable to any travel data obtained from household travel surveys, especially where the origins and destinations of the recorded trips have been geocoded and stored in a geographic information system.
Statistical Analysis of Mean Route Travel Times on Seven Primary Arterials in Chicago Metropolitan Region
Authors: Laffey Stephen C. , Nan Liu Louie , Christopher Ed J.
Published: April 2007

Presented is a statistical approach for examining multiple years of travel time data to determine if any trends can be quantified reliably by using only 4 years of observed data. Empirical data for 80 routes covering more than 4025 km were collected in the summers of 1994, 1995, 1996, and 1997 and compiled into a database for public release in the fall of 1997. From this database, seven routes were selected then sampled over all 4 years. These seven routes are primary arterials of regional significance in northeastern Illinois. A multiple regression analysis was performed on the seven arterials to determine if there was a statistically significant difference in the observed mean route travel times over the 4-year period. The regression analysis indicated that only one of seven routes experienced a statistically significant change in directional route travel time between 1994 and 1997. Because only one of seven routes was significantly different, the analyst may merge multiple years of data for an individual route into a single data set to build a more robust database. Also, quantifiable change in travel time may be difficult to perceive year by year. This has significant implications for the design of a sampling strategy that needs to measure performance on approximately 28 980 directional route km of roadways. It would be better to sample fewer routes more intensely on a regular interval than to sample many routes lightly every year.
Truck Traffic Prediction Using Quick Response Freight Model Under Different Degrees of Geographic Resolution: Geographic Information System Application in Pennsylvania
Authors: Marker John T. , Goulias Konstadinos G.
Published: April 2007

The new Quick Response Freight Manual (QRFM) was used to model truck traffic in Centre County, Pennsylvania, using Geographic Information System software. The QRFM methodology of truck traffic estimation follows the three-step process of trip generation, trip distribution, and traffic assignment. Trip generation was estimated by four classes of business employment and number of households and was aggregated to traffic analysis zones. Trip distribution employed a doubly constrained gravity model with travel time–based friction factors. User equilibrium was used for traffic assignment. Model calibration was performed by comaparing total vehicle miles traveled from model output with observed data. A comparison is made in truck traffic estimation between two models when the model resolution is changed, that is, when the size and number of traffic analysis zones (TAZs) is changed. One model uses census tracts and the other uses census blocks and block groups as TAZs. Both models use the same network, which includes all major highways and most local roads in the urbanized region of the county. Results from the two aggregation scales of analysis were compared with each other by using traffic counts in the Roadway Management System of Pennsylvania as reference data. The estimated truck traffic link volumes favor the use of the more disaggregate TAZ scheme, which is based on blocks and block groups.
Development of Intelligent Transportation System Data Management
Authors: Brydia Robert E. , Turner Shawn M. , Eisele William L. , Liu Jyh C.
Published: April 2007

The intelligent transportation system (ITS) components deployed in U.S. urban areas produce vast amounts of data. These ITS data often are used for real-time operations and then are discarded. Few transportation management centers have any mechanism for sharing the data resources among other transportation groups or agencies within the same jurisdiction. Meanwhile, transportation analysts and researchers often struggle to obtain accurate, reliable data about existing transportation performance and patterns. The development of an ITS data management system (referred to as ITS DataLink) that is used to store, access, analyze, and present data from the TransGuide center in San Antonio, Texas, is presented. Data outputs are both tabular and graphical. No user costs are associated with the system except for an Internet connection.
Developing Database of Nationwide Freight Flows for Australia
Authors: Rockliffe Nigel , Wigan Marcus , Quinlan Howard
Published: April 2007

Data on freight vehicle and commodity flows in Australia are poorly covered by official statistics, yet for many strategic purposes the analyst requires a nationwide picture of commodity flows. FreightInfo satisfies this requirement. FreightInfo is a database based on a combination of assembly techniques: the expert development of secondary data from existing national data collections, the systematic identification of major flow sources and sinks, and a rolling program of field data collection from freight consignors, consignees, and carriers. These are integrated into a coherent and consistent database covering the whole of Australia by all modes. A description of FreightInfo is presented, its creation is described, and some aggregate results relating to Australia are presented.
Beltway 8 Wetland Water Quality Project: Constructed Wetlands for Storm Water Polishing and Wetland Mitigation Banking
Authors: Knight Robert L. , Adams Robert , O’Brien Colleen , Davis Eduardo R.
Published: April 2007

The Harris County Flood Control District is implementing a wetland mitigation bank project that includes highway runoff as a significant water source. Part of this project is being implemented in cooperation with the Texas Department of Transportation through funding from the Intermodal Surface Transportation Efficiency Act for water quality improvement. This collaborative effort includes treatment and final polishing of storm water runoff from a portion of Beltway 8, northeast of Houston, Texas. The project includes approximately 89 ha (220 acres) of storm water-polishing wetlands and associated wildlife habitat. The overall train of natural treatment processes includes a tie-in to the existing beltway storm sewer, a surge basin for initial collection and storage of storm water, a pump station and force mail allowing flexible water delivery to the rest of the system, a series of polishing ponds and polishing wetland marshes, and an interconnected array of habitat wetlands and swales including ponds, littoral marshes, and transitional wetland forest areas. Design of the polishing and treatment wetlands balances the multiple goals of water quality improvement, flood-flow retention, and creation of valuable wildlife habitat.
Method To Determine Reasonableness and Feasibility of Noise Abatement at Special Use Locations
Authors: Wayson Roger L. , MacDonald John M. , Lindeman Winfield
Published: April 2007

Most states have policies in place that determine whether noise abatement is necessary and reasonable/feasible for Type I projects. These policies mirror federal guidance and apply to various land uses near the proposed project. Special land use facilities such as parks, churches, and schools are included in the policy as far as when abatement may be necessary (i.e., FHWA noise abatement criteria), but the determination of whether the abatement is reasonable or feasible may not be adequately addressed. A survey of state Departments of Transportation (DOTs) indicated that states are dealing with this need for reasonable/feasible determination for special land uses but do not have formal policies in place to address the issue. A systematic procedure would eliminate arbitrary decisions. A methodology developed for the Florida DOT to aid in the development of a procedure for special land use cases is presented. This methodology includes a feasibility flowchart that leads an individual through the process of determining whether abatement at a special land use site is feasible. The feasibility flowchart directs the individual to cease analysis because abatement is not feasible or to continue onto a reasonableness worksheet that determines whether abatement at the site is reasonable. The reasonableness worksheet leads the individual through site-specific calculations to derive an “abatement cost factor” used to determine reasonableness of abatement at the site.
Case Study in Public Perception of Noise Barrier Effectiveness
Authors: Polcak Kenneth D. , Smith Andy
Published: April 2007

I-97 and US-50 are the two major limited-access highways that connect Washington, D.C., and Baltimore to Annapolis (Maryland’s state capital). Three communities situated along US-50 and at the interchange with I-97 were considered for Type I noise barriers as the result of proposed widening and ramp additions to the highway network. Ultimately, precast concrete noise barriers were constructed in five sections on both sides of the highway in the area. Located just west of the US-50/I-97 interchange is the retirement community of Heritage Harbour. During development and construction of the community in the early and mid-1980s, the developer constructed two noncontiguous earth berms adjacent to but outside the highway right-of-way line. The noise barrier design concept developed for this project incorporated these existing earth berms into the overall US-50/I-97 barrier system. Barrier wall sections were designed to tie into both ends of the berms to mitigate flanking noise and ultimately to provide a “closed system” for the adjacent communities. STAMINA 2.0/OPTIMA modeling identified that the noise barrier construction would provide an additional 3- to 7-dBA insertion loss for homes situated near the berms. After construction of the US-50/I-97 noise barrier system, community members living directly behind the berms claimed that the new barrier walls were “funneling” noise over the top of the berms and causing the noise to be louder than it was before the barrier was constructed. The Maryland State Highway Administration monitored postbarrier noise levels in response to the community’s request. The monitored levels confirmed OPTIMA predicted noise levels and did not support claims that noise levels had become worse after barrier construction. Under prebarrier conditions, it was hypothesized that noise particularly from heavy vehicles unshielded by the existing berms was substantial enough that vehicle noise passing over the berms was being masked, so that the source direction was not always discernible. Once the “flanking noise” was abated by the barrier walls, vehicle noise passing over the berms dominated. The results of the noise monitoring and an explanation of identified phenomenon were successfully presented to the community. The case study presents the US-50/I-97 berm/barrier public perception issues, discusses the project’s applicability to previous “public noise perception” research, and suggests public involvement techniques that could prepare communities for unique acoustic situations.
State-of-the-Art Prediction and Control of Road Traffic Noise in France
Authors: Bérengier Michel C. , Anfosso-Lédée Fabienne
Published: April 2007

Because traffic noise is considered by the French population as the primary environmental nuisance, prediction of road traffic noise and development of efficient noise control techniques is very important. The first step is to analyze the source, the main part of which is due to the contact between tires and the road pavement. Many efforts have been devoted to the assessment of a reliable measurement method, and a classification of road pavements in relation to noise has been established for some years. To abate road traffic noise, special attention has been paid to low-noise pavements. Thus, the modeling of the absorption properties of porous asphalts has been particularly studied in the past 10 years. The second step is to understand the physics of sound propagation outdoors, especially the meteorological effects on the propagation of road traffic noise. Both theoretical and experimental approaches have been undertaken. Finally, the effect of road noise barriers of any shape on the propagation of road noise and their interaction with porous road surfaces have been investigated by using numerical models.
Assessment of Water Pollutants from Asphalt Pavement Containing Recycled Rubber in Rhode Island
Authors: Vashisth Pradeep , Lee K. Wayne , Wright Raymond M.
Published: April 2007

Use of recycled rubber in asphalt pavement has been widely accepted since it overcame the scrap tires disposal problem and it has many advantages—for example, savings in quantity and cost of construction materials. In this study, hot-mix asphalt (HMA) specimens with or without crumb rubber modifier (CRM) were analyzed under different environmental conditions. The CRM was added into HMA by two processes (wet and dry processes). The CRM was procured from two different sources to prepare specimens (one source for each process). Cylindrical specimens were tested in a particle entrainment system at two different temperatures and three different pH levels. Slab specimens were simulated for rainfall conditions. Water samples were collected in all three phases of the study: preliminary investigations on individual CRM, water quality evaluation for cylindrical HMA specimens at various environmental conditions, and water quality evaluation for slab HMA specimens under simulated rainfall conditions. Collected water samples were analyzed for six metals: chromium, lead, nickel, copper, cadmium, and zinc. A general trend for these metals indicates that zinc was leached in higher concentrations than other metals and all the metals were leached in higher concentrations at higher temperature (maximum asphalt pavement temperature) and at lower pH (pH 2.0 conditions). Finally, based on the limited scope of this effort and comparison with water quality criteria, there does not appear to be any evidence that there will be a detrimental effect on the environment or to human health.
Combined Anaerobic/Aerobic Biostimulation for Remediation of Rail Yards Contaminated by Diesel Engine Repair and Maintenance
Authors: Hirl Patrick J.
Published: April 2007

Perchloroethylene (PCE) and trichloroethylene (TCE) have been commonly used in the repair and maintenance of diesel engine locomotives. Improper handling, storage, and disposal lead to contamination of rail yard soils and groundwater with chlorinated ethylenes. Benzene, toluene, ethyl-benzene, and xylene (BTEX) are also common contaminants at rail yards because of the leakage of diesel fuel storage tanks and spills of diesel fuel. Co-contamination of groundwater with BTEX and chlorinated ethylenes allows for the application of anaerobic/aerobic bioremediation to achieve mineralization of both types of compounds. Bench scale laboratory experiments were run to select and enrich for an undefined, mixed, microbial consortium able to mediate PCE dechlorination to dichloroethylene (DCE), mineralization of the DCE, and mineralization of aromatic compounds. A periodically operated suspended culture reactor created alternating anaerobic/aerobic environments. When glucose was added to the reactor as the sole electron donor, the mixed culture dechlorinated PCE to cis-1,2-dichloroethylene (cDCE) in 24 h. When phenol and glucose were added to the reactor, the mixed culture dechlorinated PCE to cDCE, metabolized the influent phenol, and oxidized 90 percent of the cDCE produced in 24 h. Because both phenol and toluene can induce the enzymes necessary for mineralization of TCE and DCE, an anaerobic/aerobic bioremediation approach has potential application for remediation of groundwater at rail yards co-contaminated with diesel fuel and chlorinated ethylenes.
Innovative Use of the Cone Penetrometer Test for Highway Environmental Site Characterization and Monitoring
Authors: Mitchell Gayle , Shinn James D.
Published: April 2007

The cone penetrometer test (CPT) is an important tool for use in geotechnical and environmental site characterization for the transportation sector. Its role as both a primary investigation technique and as a component in an overall exploration strategy are explained. The types of sensors currently used with the CPT are discussed. Among the most promising new CPT technologies are a soil moisture probe and a fluorescence detection system. Laboratory and field results using a soil moisture probe jointly developed by Ohio University and Applied Research Associates for use with the CPT are presented. Also, application of the fuel fluorescence detector (FFD) for locating hydrocarbon contamination is presented, and typical data obtained with the FFD are illustrated and discussed.
Environmental Justice Evaluation: Wilmington Bypass, Wilmington, North Carolina
Authors: Lane Leigh Blackmon , Hoffeld Scott , Griffin David
Published: April 2007

Among the common mandates of agency guidelines implementing Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, is the determination of whether the subject action or project will cause disproportionately high and adverse human health or environmental effects on minority or low-income populations. This determination is often troublesome because it requires the analyst to know or define disproportionate impacts. A method is provided for defining disproportionate within the context of an environmental justice evaluation that was conducted for the Wilmington Bypass environmental impact statement. In response to strong local opposition to one of the alignment alternatives of the Wilmington Bypass and to address the perception that this community’s residents were not involved in the planning process, the Wilmington Bypass public involvement program was augmented to include a citizens’ informational workshop, project development meetings, and community liaison meetings. A brief history is provided of the Wilmington Bypass project, highlighting the public involvement surrounding the environmental justice evaluation. Discussions of the scoping process and delineation of the study area are followed by discussions of the reference population development for the minority and low-income populations. Particular emphasis is given to the use of available census demographic and socioeconomic data and graphical display of these data with the use of a geographic information system. Impact evaluations and mitigative responses for issues determined relevant for the environmental justice analysis conclude the discussion. Conclusions and recommendations for further study are provided.
Method for Including Societal Issues in Transportation Decisions
Authors: Richardson Barbara C. , Kostyniuk Lidia P.
Published: April 2007

A method for including societal and institutional issues in transportation decisions is demonstrated through the use of the multiorganization decision analysis (MODA) process. A modification of decision risk analysis methods that have been successfully used in corporate environments, MODA takes into consideration the diversity of decision makers in transportation implementation decisions who come from public and private sectors and include a mix of agencies, institutions, and interest groups. The MODA process structures a set of interactions among a decision-making team, an analysis team, and facilitators. The steps of MODA include development of a shared vision statement, framing of the problem, generation of alternative solutions, analysis of alternatives, and a decision. Consensus by decision makers is required at each step of the process. The MODA process was demonstrated on the decision of whether a hypothetical community, representative of those in southeastern Michigan, should upgrade its paratransit service to include the use of intelligent transportation system technology. Through the MODA process, the factors and interrelationships relevant to the decision makers were identified. MODA accommodated their disparate views and disagreements, enabling them to agree on one solution in a relatively short period of time.
Joint Seal Practices in the United States: Observations and Considerations
Authors: Morian Dennis A. , Stoffels Shelley
Published: April 2007

In recent years, states have adopted a wide variety of joint sealing practices for jointed rigid pavements, based on local experience. Over time, the adoption of quality control/quality assurance practices has resulted in decreased inspection and attention that ensure compliance with good joint seal installation practices. At this time, several agencies have adopted or are considering a policy of providing for rigid pavement joints by using a single 3-mm (1/8-in.) saw cut. Agencies are either leaving this saw cut unfilled or filling it with hot-poured sealant, recognizing that it is not effectively sealed. This practice may prove acceptable where positive drainage features are naturally occurring (coarse-grained subgrade) or where climates are very hot and dry, resulting in minimal joint movement. Other agencies continue to use established joint-sealing practices with good pavement performance results. This approach continues to be a prudent one, particularly in wet climates with fine-grained subgrade materials. Here slab-support erosion has been shown to result in accelerated deterioration of jointed rigid pavements.
Winter Road Condition Recognition Using Video Image Classification
Authors: Kuehnle Andreas , Burghout Wilco
Published: April 2007

Sweden spends 1.7 billion Crowns on winter road maintenance annually. A large part of this money goes into plowing, salting, and sanding of the roads. The decision about what maintenance to perform is made, in part, based on data received from road weather information stations, some of which are also equipped with video cameras. These video cameras form an additional unexploited sensor for determining the road condition during winter. Images taken from a handheld roadside video camera are investigated here to see if it is possible to determine the road state (dry, wet, snowy, icy, snowy with tracks) from the video images alone. The system is intended to supplement the other weather station measurements, such as temperature and wind speed, and make better maintenance decisions and quality control of maintenance possible. The results indicate that it is possible to distinguish between all road states except for ice/wet and ice/tracks. Typical class separations are a Mahanalobis distance between 0 and 2. Neural networks with three or four input features, three to five hidden neurons, and a sigmoid-sigmoid-linear architecture are used to classify the road state. Rates of correct classification are typically 40 to 50 percent with these networks. There are useful feature combinations, including purely monochrome features, which do not depend on the network architecture.
Life Cycle Cost-Benefit Model for Road Weather Information Systems
Authors: McKeever Benjamin , Haas Carl , Weissmann Jose , Greer Rich
Published: April 2007

To ensure safer driving conditions on highways, state highway agencies are exploring the use of new technologies that will improve the flow of information about hazardous road conditions. These technologies are called Road Weather Information Systems (RWIS). The objective of this paper is to provide a systematic methodology for highway agencies to evaluate the costs and benefits associated with implementing RWIS. This objective was achieved through the development of a life cycle cost-benefit model for RWIS. This analysis tool provides highway agency decision makers with a methodology through which different RWIS implementation alternatives can be evaluated from economic, qualitative, and environmental perspectives. A case study demonstrating the use of the RWIS cost-benefit model also is included. The purpose of the case study is to evaluate whether or not it is cost-beneficial to implement an RWIS on Interstate 20 near Abilene, Texas. The model determined that it was cost-beneficial to implement this system.
Driver Perception–Brake Response in Stopping Sight Distance Situations
Authors: Fambro Daniel B. , Koppa Rodger J. , Picha Dale L. , Fitzpatrick Kay
Published: April 2007

One of the most important requirements in highway design is the provision of adequate stopping sight distance at every point along the roadway. At a minimum, this sight distance should be long enough to enable a vehicle traveling at or near the design speed to stop before reaching a stationary object in its path. Stopping sight distance is the sum of two components–brake reaction distance and braking distance. Brake reaction distance is based on the vehicle’s speed and the driver’s perception–brake reaction time (PBRT). Four separate, but coordinated, driver braking performance studies measured driver perception–brake response to several different stopping sight distance situations. The results from the driver braking performance studies suggest that the mean perception–brake response time to an unexpected object scenario under controlled and open road conditions is about 1.1 s. The 95th percentile perception–brake response times for these same conditions was 2.0 s. The findings from these studies are consistent with those in the literature: that is, most drivers are capable of responding to an unexpected hazard in the roadway in 2.0 s or less. Thus, the American Association of State Highway and Transportation Officials’ perception–brake response time of 2.5 s encompasses most of the driving population and is an appropriate value for highway design.
Fatigue and Automation-Induced Impairments in Simulated Driving Performance
Authors: Desmond Paula A. , Hancock Peter A. , Monette Janelle L.
Published: April 2007

A driving simulator study investigated the effect of automation of the driving task on performance under fatiguing driving conditions. In the study, drivers performed both a manual drive, in which they had full control over the driving task, and an automated drive, in which the vehicle was controlled by an automated driving system. During both drives, three perturbing events occurred at early, intermediate, and late phases in the drives: in the automated drive, a failure in automation caused the vehicle to drift toward the edge of the road; in the manual drive, wind gusts resulted in the vehicle drifting in the same direction and magnitude as the “drifts” in the automated drive. Following automation failure, drivers were forced to control the vehicle manually until the system became operational again. Drivers’ lateral control of the vehicle was assessed during three phases of manual control in both drives. The results indicate that performance recovery was better when drivers had full manual control of the vehicle throughout the drive, rather than when drivers were forced to drive manually following automation failure. Drivers also experienced increased tiredness, and physical and perceptual fatigue symptoms following both drives. The findings have important implications for the design of intelligent transportation systems. Systems that reduce the driver’s perceptions of task demands of driving are likely to undermobilize effort in fatigued drivers. Thus, the results strongly support the contention that human-centered transportation strategies, in which the driver is involved in the driving task, are superior to total automation.
Drivers’ Attitudes, Understanding, and Acceptance of Passing Lanes in Kansas
Authors: Mutabazi Madaniyo I. , Russell Eugene R. , Stokes Robert W.
Published: April 2007

Traditionally, highway improvement project evaluation is done without incorporating highway users’ views. The Kansas Department of Transportation (KDOT) wants drivers to be satisfied and have “good feelings” about its passing lanes program. KDOT needs input to decide whether passing lanes are efficient, safe, and acceptable to the public. Drivers’ views were solicited via a questionnaire survey which was part of a comprehensive study on passing lanes in Kansas. Generally, drivers support the passing lane program and suggest construction of more passing lanes. Drivers think that passing lanes are more beneficial for improving safety than for saving time. They are equally divided on the length of passing lanes between “too short” and “just right,” although the provided lengths are within the recommended optimum lengths found in the literature. The “too short” responses could be due to existing passing lane spacings, preference of four-lane highways over two-lane highways, and difference in local conditions from those used to determine lengths. Drivers cited fellow drivers’ failure to follow signs and markings properly, and failure to use the lanes properly; this seems to indicate that improvements in signing and pavement markings should be considered. A smaller proportion of drivers, satisfied with a lower frequency of local travel on a route closer to the state’s borders (i.e., more unfamiliar drivers), suggests the importance of standardizing highway operating and design practices throughout the country.
Automobiles on Horizontal Curves: Experiments and Observations
Authors: Felipe Emmanuel , Navin Francis
Published: April 2007

Statistical information on the basic variables involved in driving through a horizontal curve was obtained using a 4×4 Latin square design experiment to measure the action of automobile drivers in test track horizontal curves. The independent variables used in the test curves were speed (comfortable, fast); pavement surface (dry, wet); driver (male, female); and curve radius (16 m, 26 m, 60 m, 100 m). The measured output was the driver’s selected speed and corresponding lateral acceleration. In addition, the passengers indicated their comfort level on a four-point semantic scale. Expert drivers also drove the test curves to establish the upper limits of the driver-vehicle-tire system. Field observations of four curves along a two-lane rural mountain highway measured driver vehicle speed, lateral acceleration, and lateral position. The results indicate that, for a comfortable ride, drivers are limited by their comfortable lateral acceleration on small radius curves and seek the “environmental speed” on large radius curves.
Modeling Pavement Response to Vehicular Traffic on Ohio Test Road
Authors: Kennedy James C. , Douglas Everhart R.
Published: April 2007

Methods of cost allocation for highway pavement rehabilitation and maintenance activities and pavement management estimations are based on empirical and semiempirical founded predictions that come up short, particularly when a roadway is subjected to heavy multiaxle vehicles. Additionally, materials used in constructing the pavement structure do not always behave in an elastic manner, and the ability to predict the pavement response in the presence of other than elastic material behavior is essential. Finally, prediction of pavement states of distress, based on empirical methods, and elastic material behavior is inadequate, particularly when traffic of heavy vehicles is involved. Battelle has been working on a mechanistic approach to address the issues and concerns at the core of current pavement design methods. The overall approach consists of combining three major software modules—a structural module that includes a general primary response model, a material characterization module, and a damage and distress module—are interconnected so that the influence of one on the other is continually updated. Four miles of highway pavement have been heavily instrumented with structural and environmental sensors so that pavement response can be monitored on both short- and long-term bases. Field test results from these pavements have been acquired and, along with laboratory data, have been used to partially validate and provide insight into pavement behavior under various loading conditions. The unique requirements for the design and implementation of the structural and environmental sensing elements are discussed. The mechanistic aspects in the software for the structural and material models are described, and predicted and field-measured results are compared.