Report Date: May 2007. This project was aimed at developing and evaluating a sensor-based nondestructive testing (NDT) method for online monitoring of highway bridges without using any past baseline data. A theoretical framework of the proposed baseline-free NDT technique was developed along with a time reversal process (TRP), and a NDT methodology for detecting cracks in bridge steel girders was formulated. To prove the feasibility of the proposed concept, research addressed the following key questions: What is the practical sensing range of TRP for damage detection. Can different types of be selectively detected and quantified. Do sensor conditions affect damage detection. Do undesirable operational and environmental conditions affect damage detection. Is the proposed TRP applicable to more complex structural geometries. The sensing range of TRP was found to be significantly larger than that achieved by conventional NDT methods, and the active sensing device was able to propagate up to 40 m.

Accession No. PB2007109637.

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Report Date: January 2007. This project evaluated the application of super elastic shape memory alloy (SMA) reinforcement in combination with engineered cementitious composites (ECC) in bridge columns to minimize earthquake damage. Based on initial evaluation, Nitinol SMA and ECC compositions were selected for application in bridge columns. An analytical study was performed to determine optimum material properties and configuration for the concrete column. Bridge columns incorporating a combination of SMA and ECC or conventional concrete were constructed and subjected to quasi-static cyclic tests. The first column (RSC) utilized conventional concrete and steel reinforcement, the other two (RNC and RNE) utilized engineered cementitious composites (ECC) in the plastic hinge. The final report includes important experimental and analytical data to help develop design guidelines for improving the seismic response of bridge columns using SMA and ECC materials.

Accession No. PB2007109640.

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Report Date: August 2007. The AASHTO LRFD Bridge Design Specifications and the AASHTO LRFD Bridge Construction Specifications were reviewed to identify provisions that affect the use of lightweight concrete. A synthesis of research relevant to the provisions was then compiled. Proposed research problem statements were developed to generate data to update the specifications in areas where gaps exist for lightweight concrete.

Accession No. PB2007110768.

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Report Date: July 2007. Eleven systems combining epoxy-coated reinforcement with another corrosion protection system are evaluated using the rapid macrocell, Southern Exposure, cracked beam, and linear polarization resistance tests. The systems include bars that are pretreated with zinc chromate to improve the adhesion between the epoxy and the reinforcing steel; two epoxies with improved adhesion to the reinforcing steel; one inorganic corrosion inhibitor, calcium nitrite; two organic corrosion inhibitors; an epoxy-coated bar with a primer containing microencapsulated calcium nitrite; the three epoxy-coated bars with improved adhesion combined with the corrosion inhibitor calcium nitrite; and multiple coated bars with an initial 50-um (2-mil) coating of 98 percent zinc and 2 percent aluminum followed by a conventional epoxy-coating. The systems are compared with conventional uncoated reinforcement and conventional epoxycoated reinforcement. The results presented in this report represent the findings obtained during the first half of a 5-year study that includes longer-term ASTM G 109 and field tests.

Accession No. PB2007111508.

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Report Date: July 2007. In this research, the axial force transfer within Cast-In-Steel-Shell (CISS) piles through the surface bond and through mechanisms fixed to the steel shell internal surface was studied. Mechanisms studied included a shear ring, welded bar, weld bead, shear studs, cross bar, and tread plate. Other parameters studied in this experiment included the effect of shear ring spacing, the effect of the D/t ratio on the shear ring, and the effects of expansive concrete, D/t ratio, and surface condition. Test units were subjected to a quasi-static reversed cyclic axial loading. All mechanisms exhibited a noticeable increase in the axial force capacity, in both compression and tension. Test units with a circumferential mechanism (e.g. shear ring) had a ductile performance, whereas distributed mechanisms had a non-ductile performance. Circumferential mechanisms were effective to the extent that either the steel shell capacity was obtained, through circumferential yielding at the mechanism, or the reinforced concrete core capacity was obtained. This report will present the experimental results, a prediction method and results from finite element modeling.

Accession No. PB2007112633.

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Report Date: 2007. Bridges constitute critical nodes of transportation systems, and therefore, ensuring their continuous operation is of utmost importance for safe and efficient transportation. Currently, visual inspections and simplified analysis techniques are employed for condition assessment and for decision making about bridges. A novel approach to bridge condition assessment is Structural Health Monitoring (SHM), defined as the measurement of operating and loading environment and critical responses of a system to track and evaluate incidents, anomalies, damage and deterioration. The objective of the project is to develop an SHM framework for integrative information system design. This framework is expected to improve bridge safety and to have efficient operation, effective and low cost maintenance by taking advantage of new technological advances. Movable bridges are considered as focus bridge type, because these bridges exhibit various structural, maintenance and operational problems. In the study, inspection and maintenance records of the movable bridges are analyzed to determine the current condition of these bridges as given in these reports. Then, numerical and experimental studies are developed and conducted. Data processing and some novel analysis methods that are being employed by the writers are summarized along with examples from laboratory studies.

Accession No. PB2007112670.

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Report Date: August 2007. Freight railroads account for over 40 percent (by weight) of the nation's freight on a privately owned network that was largely built almost 100 years ago and includes over 76,000 railroad bridges and over 800 tunnels. As requested, GAO provides information on this infrastructure, addressing (1) the information that is available on the condition of railroad bridges and tunnels and on their contribution to railroad congestion, (2) the federal role in overseeing railroad bridge and tunnel safety, (3) the current uses of public funds for railroad infrastructure investments, and (4) criteria and a framework for guiding any future federal role in freight infrastructure investments. GAO reviewed federal bridge safety guidelines and reports, conducted site visits, and interviewed federal, state, railroad, and other officials. Little information is publicly available on the condition of railroad bridges and tunnels and on their contribution to congestion because the railroads consider this information proprietary and share it with the federal government selectively. GAO has identified critical questions that can serve as criteria for reexamining the federal role in freight investments--including railroad bridge and tunnel investments--and a framework for implementing that role that includes identifying national goals, clarifying stakeholder roles, and ensuring that revenue sources and funding mechanisms achieve maximum national public benefits. The Department of Transportation's draft Framework for a National Freight Policy takes a step forward, but more is needed to guide the implementation of a federal role in freight transportation investments.

Accession No. PB2007112672.

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Report Date: November 2006. This project demonstrated the application of a new mobile geophysical method based on electromagnetic induction technology to detect subsurface features and objects for highway-related projects. Two highway projects were identified in collaboration with Caltrans for evaluating the mobile geophysical technology. The first project was a road widening Donner Road Rehabilitation Project along highway 1-80 (Nevada County). The IDEA work in these projects investigated the geological composition of the soils beneath I-80. The second project was a bypass Cherry Avenue Project between Taft and Bakersfield (Western Kern County). The IDEA work determined soil texture density differences, identified plumes and selected geotechnical boring locations. The electromagnetic signatures were correlated with soil conditions and used to identify differences in geology, landform, and roadbed materials. In both projects, the data obtained by the geophysical equipment provided a more complete provided a more complete understanding of the subsurface conditions and allowed updating and improving the accuracy of the construction plans.

Accession No. PB2007109638.

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Report Date: July 2007. The objective of this study was to evaluate the geologic formations, units, and surficial deposits within Pennsylvania as they relate to the potential to form acid rock drainage (ARD). The primary aim of this effort was to assist PennDOT in the avoidance of the potential environmental impacts associated with these pyrite-bearing formations during road construction, as well as to assist in avoiding the negative impacts upon engineered structures that are often associated with ARD. An ancillary objective was to develop predictive models, where feasible, to predict the location and relative severity of ARD and its associated environmentally deleterious effects. Three broad types of potentially acid-producing sulfide-bearing groups were identified. The first group, the black shales predominantly of the Valley and Ridge Province, may cause ARD and have been observed to swell, leading to heave of engineered structures in some cases. Based on 94 surface samples of the black shales, a preliminary north/south geographic trend in their net neutralization potential has been identified extending between Centre County and Fulton County. A second group, consisting of the mostly flat-lying, coal-bearing successions of Pennsylvanian age, has long been known to contribute to ARD problems. A general trend in decreasing percent sulfur of the coal measures from the southeast to northwest has been perceived based on large amounts of overburden chemical analyses and has been attributed to the initial depositional environment of the coals and overburden materials. The third group, a number of isolated sulfide deposits, particularly those associated with dominantly sandstone lithologies, appears to be largely structurally controlled. A preliminary predictive model has been developed and some important geographic trends have been delineated; however, the isolated deposits and some of the black shales deserve more attention in order to identify any spatial and temporal relationships allowing for predictive interpretation. Finally, a simplified flowchart has been developed to assist in delineating the potential for significant environmental and engineering impacts based upon the chemical and mineralogical characteristics of a deposit.

Accession No. PB2007111519.

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Report Date: 2007. The Ohio-Kentucky-Indiana Regional Council of Governments (OKI), the Metropolitan Planning Organization (MPO) located in Cincinnati, is engaged in a process to improve its ability to plan transportation improvements through the use of economic analysis methods. These methods are intended to augment OKIs existing evaluation approaches to small- and large-scale transportation projects. For analysis of individual projects in the Transportation Improvement Program (TIP), OKI staff utilizes a Prioritization Process, in which scores are applied to a host of transportation, planning, and cost factors. Projects are then ranked according to total scores. In the past, OKI made occasional use of economic analysis for large corridor projects, although typically this analysis was limited to very large projects and was performed by outside experts. To attain broader application of benefit-cost techniques and also reduce the cost of such analyses, OKI has recently explored methods to do in-house economic analyses of surface transportation projects. As part of this effort, OKI investigated the potential use of the FHWAs Surface Transportation Efficiency Analysis Model (STEAM) software for the analysis of large projects and clusters of smaller projects.

Accession No. PB2007113172.

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Report Date: 2007. Weather causes a variety of impacts on the transportation system. While severe winter storms, hurricanes, or flooding can result in major stoppages or evacuations of transportation systems and cost millions of dollars, day-to-day weather events such as rain, fog, snow, and freezing rain can have a serious impact on the mobility and safety of the transportation system users. These weather events can result in increased fuel consumption, delay, number of accidents, and significantly impact the performance of the transportation system. The overall goal of the research work undertaken in this study was to develop a better understanding of the impacts of weather on traffic flow. The research was intended to accomplish the following specific objectives: (1) Study the impact of precipitation on macroscopic traffic flow parameters over a full range of traffic states; (2) Study the impact of precipitation on macroscopic traffic flow parameters using consistent, continuous weather variables; (3) Study the impact of precipitation on macroscopic traffic flow parameters on a wide range of facilities; (4) Study regional differences in reaction to precipitation; and (5) Study macroscopic impacts of reduced visibility.

Accession No. PB2007109646.

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Report Date: 2007. Our roads and highways cross your lands. Highway corridors connect us all for our commerce, recreational travel, workday commute, and more. The mobility and safety provided by U.S. highways is a proud accomplishment of the Federal Highway Administration and its State and local partners. The same highways that move people and products are blamed for moving invasive species. Some research supports this claim. Because of increased commerce, human habits, well-traveled tires, wind gusts and runoff, we intuitively know that weed seeds move to and from highway corridors with added speed. Over the years, highway managers discovered that their own construction and maintenance activities unwittingly exacerbated the spread of invasives. Consequently, Best Management Plans (BMP) were adopted nationwide. But what happens on the other side of the right-of-way fence is outside roadside managers' control. Private landowners and public land managers control or rail to control invasive plants on their side of the fence. The weed seed source does not always originate on the highway side. Weeds move both directions. Working with our neighbors through increased awareness and partnerships has become a sign of the times. A resources diminish, and weed populations escalate, no land manager has any other choice. When Executive Order 13112 was signed in 1999, all federal agencies and others developing federally-funded projects were asked to cooperate and coordinate on the invasive plant issue.

Accession No. PB2007111541.

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Report Date: July 2007. Native varieties of grasses, having evolved over many eons, have clearly demonstrated their ability to withstand harsh environmental conditions and create stable vegetation communities. The Texas Department of Transportation (TxDOT) has been seeding native grass species along with adapted grass species as part of its vegetation establishment program for many years. Over the past decade, the use of native grasses has greatly increased as more people have become aware of their restoration and habitat advantages as well as their beauty. TxDOT would like to test the feasibility of using an all-native species seeding mix for use in the establishment of roadside vegetation in roadway construction projects. This project surveys available native grass species and tests selected varieties as part of a mix under roadside conditions to determine which if any, may be desirable additions to the current seeding program.

Accession No. PB2007112704.

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Report Date: December 2006. The Freight Performance Measures Initiative is a Federal Highway Administration (FHWA) effort to measure speed and travel-time reliability on freight-significant corridors and crossing and delay time at major U.S. land border crossings. This report, based on the first full year of data for five freight-significant corridors, presents initial research findings. This research establishes a foundation for working with regional, state and local transportation agencies and the freight industry to further refine this work and develop tools and products to meet a myriad of frieght data needs.

Accession No. PB2007114046.

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Report Date: October 2006. The Freight Technology Assessment Tool (FTAT) helps public and private organizations and individuals evaluate the effect that a technology, or group of technologies, has on the end-to-end business process. The technology is evaluated based on an array of performance measures. This information can be used to prioritize future projects. Making good transportation choices is critical to continued economic growth. FTAT combines and customizes well-defined and accepted industrial engineering approaches and benchmarking and uses best practices to determine the costs and benefits of using a particular technology.

Accession No. PB2007114047.

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Report Date: June 2007. This document was prepared for the U.S. Department of Transportation, Federal Transit Administrations (FTA) Office of Research, Demonstration and Innovation. It presents an evaluation of the Silver Line Waterfront Bus Rapid Transit project and its one of a series of case study evaluations of BRT systems that comprise the national BRT Consortium. The content of this document follows the Guidelines for the Evaluation of Bus Rapid Transit Demonstration Projects developed by the Volpe National Transportation Systems Center. The specific elements that are the focus of the Silver Line BRT evaluation are derived from the Characteristics of Bus Rapid Transit for Decision Making published by the FTA in August 2004. These include running ways, stations, vehicles, fare collection, intelligent transportation systems (ITS) and service and operating plans. The objectives of the evaluation are to determine extent and impact of travel time improvements and system reliability; measure ridership change; evaluate impact of BRT technologies; assess role of branding and marketing; examine how the Silver Line Waterfront BRT has affected the metropolitan Boston transportation network; determine effect of the Silver Line Waterfront on land use and transit oriented development (TOD); and evaluate overall safety and security of the Silver Line Waterfront service. The report also offers a number of lessons learned from the Silver Line Waterfront program.

Accession No. PB2007109633.

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Report Date: 2007. An evaluation of aged asphalt concrete (AC) was performed during the period February to December 2006 at the Vicksburg Airport (Vicksburg, MS), Hood Army Airfield and Robert Gray Army Airfield (Fort Hood, TX), Lawson Army Airfield (Fort Benning, GA), Cairns Army Airfield (Fort Rucker, AL), Butts Army Airfield (Fort Carson, CO), and Kandahar Airfield (Kandahar, Afghanistan) to develop a method for predicting the performance of aged AC surfaces in situ. A portable seismic pavement analyzer (PSPA) was used on the in situ AC pavements to determine the pavement modulus. The aged AC samples obtained from the military airfields were brought to the U.S. Army Engineer Research and Development Center for further laboratory testing. Various asphalt mixture and binder properties were determined from the samples, indirect tensile strength tests were run on core samples, and beam fatigue tests were performed on beam samples. The results from this study were used to develop adjustments to the current Department of Defense (DoD) fatigue criterion for the purpose of improving fatigue life predictions for aged AC surfaces. Aged AC surfaces are considered to be 10 years old or older. The most accurate adjustment to the current DoD criterion required both asphalt modulus (from PSPA) and binder stiffness (from dynamic shear rheometer) as input.

Accession No. ADA470955.

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Report Date: August 2007. The response of flexible pavement is largely influenced by the resilient modulus of the pavement profile. Different methods/approaches have been adopted in order to estimate or measure the resilient modulus of each layer assuming an average modulus within the layer. In order to account for the variation in the modulus of elasticity with depth within a layer in elastic pavement analysis, which is due to temperature or moisture variation with depth, the layer should be divided into several sublayers and the modulus should be gradually varied between the layers. A powerful and innovative computer program has been developed for elastic pavement analysis that overcomes the limitations of the existing pavement analysis programs. The new program can predict accurately and efficiently the response of the pavement consisted of any number of layers/sub layers and any number of loads. The complexity of the tire-pavement loading configuration can be modeled easily as well.

Accession No. PB2007111521.

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Report Date: August 2007. Ultra-high performance concrete (UHPC) is a relatively new material which has demonstrated good durability properties, high compressive strength, and usable tensile resistance. Recent material characterization and structural behavior studies have shown the average compressive strength to be 28 ksi while a tensile strength of greater than 1.5 ksi can be maintained throughout a tensile strain of approximately 0.010. These desirable mechanical properties make UHPC a worthy material for use in our nations highly stressed bridge decks. Since UHPC exhibits a unique flexural behavior, a design methodology must be developed to distinguish it from traditional reinforced concrete behavior. This report details UHPC flexural behavior, presents a design methodology, and presents the analysis of a two-way ribbed precast bridge deck. With the absence of design specifications for UHPC, the 2006 AASHTO LRFD Bridge Design Specifications were used where appropriate in the design and analysis of the bridge deck. From the proposed design methodology, mechanics of materials, and strain compatibility, the UHPC deck cross section in this report is analyzed for positive and negative moment capacities. The analysis reveals the proposed UHPC deck design to be capable of resisting the developed design loads. Further verification through physical testing of a full-scale UHPC two-way ribbed deck slab is recommended.

Accession No. PB2007112112.

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Report Date: August 2007. Long-life concrete pavements require less frequent repair and rehabilitation and contribute to highway safety and congestion mitigation. The Federal Highway Administration, American Association of State Highway and Transportation Officials, and National Cooperative Highway Research Program sponsored a scanning study to identify design philosophies, materials requirements, construction procedures, and maintenance strategies used in Europe and Canada to build long-life concrete pavements. The scan team observed that concrete pavements in the countries visited are designed for 30 or more years of low-maintenance service life. The countries are responding to pavement-tire noise issues in urban areas by using exposed aggregate surface. Some use catalog designs for pavements and geotextiles as a separator layer between the cement-treated base and concrete pavement. Team recommendations for U.S. implementation include using two-lift construction to build pavements, developing pavement design catalogs, using better-quality materials in pavement sub-bases, paying greater attention to cement and concrete mixture properties, using a geotextile interlayer to prevent concrete slabs from bonding to the cement-treated base, and using exposed aggregate surfaces to reduce noise.

Accession No. PB2007112637.

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Report Date: July 2007. Initial cost considerations have historically precluded widespread utilization of high performance (corrosion resistant) reinforcements such as stainless steels in bridge construction. However, with the advent of life-cycle cost analysis as a project planning tool and of a requirement that major bridge structures have a 75- to 100-year design life, the competitiveness of such steels has increased such that enhanced attention has focused in recent years upon these materials. This investigation was initiated to evaluate the corrosion resistance of various types of corrosion resistant reinforcement, including new products that are becoming available, in bridge structures that are exposed to chlorides. Both long-term (4-year) test yard exposures and accelerated laboratory experiments in simulated concrete pore waters are being performed. The ultimate objective is to, first, evaluate the corrosion properties and rank the different candidate materials and, second, develop tools whereby long-term performance in actual structures can be projected from short-term tests. This interim report presents results from the initial 3 years of an overall 5-year program.

Accession No. PB2007112639.

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Report Date: May 2007. This report characterizes the longitudinal profiles of sixteen pavement sections within the Arizona Specific Pavement Studies 1 project throughout their service life. This project was built and monitored as part of the Long-Term Pavement Performance Study. Road profile measurements were collected on this site about once per year since the winter after it was opened to traffic. This study analyzed the profiles in detail by calculating their roughness values, examining the spatial distribution of roughness within them, viewing them with post-processing filters, and examining their spectral properties. These analyses provided details about the roughness characteristics of the road and provided a basis for quantifying and explaining the changes in roughness with time, as well as linking profile properties to each sections maintenance history and observations of surface distress.

Accession No. PB2007112696.

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Report Date: May 2007. This report characterizes the longitudinal profiles of eight pavement sections within the Arizona Specific Pavement Studies 1 project throughout their service life. This project was built and monitored as part of the Long-Term Pavement Performance Study. Road profile measurements were collected on this site about once per year since the winter after it was opened to traffic. This study analyzed the profiles in detail by calculating their roughness values, examining the spatial distribution of roughness within them, viewing them with post-processing filters, and examining their spectral properties. These analyses provided details about the roughness characteristics of the road and provided a basis for quantifying and explaining the changes in roughness with time, as well as linking profile properties to each sections maintenance history and observations of surface distress.

Accession No. PB2007112697.

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Report Date: May 2007. This report characterizes the longitudinal profiles of five pavement sections within the Arizona Specific Pavement Studies 1 project throughout their service life. This project was built and monitored as part of the Long-Term Pavement Performance Study. Road profile measurements were collected on this site about once per year since the winter after it was opened to traffic. This study analyzed the profiles in detail by calculating their roughness values, examining the spatial distribution of roughness within them, viewing them with post-processing filters, and examining their spectral properties. These analyses provided details about the roughness characteristics of the road and provided a basis for quantifying and explaining the changes in roughness with time, as well as linking profile properties to each sections maintenance history and observations of surface distress.

Accession No. PB2007112698.

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Report Date: July 2007. The work contained in this interim report provides a case study describing the design, construction, initial structural evaluation, and performance predictions of the full-depth perpetual pavement constructed on SH 114 in the Fort Worth District. Based on the research findings, recommended improvements to design and construction practices are proposed. The research methodology and scope of work included data collection, laboratory and field testing, computational simulations, and performance predictions. Laboratory testing for characterizing the asphalt mixture properties included the Hamburg, the Overlay Tester, Dynamic Modulus, and Repeated Load Permanent Deformation tests. Asphalt-binder testing was accomplished with the Troxler Ignition Oven and the Dynamic Shear Rheometer, respectively. Field testing involved visual surveys, coring, infra-red quality control tests, forensic investigations, and non-destructive performance evaluations using Ground Penetrating Radar (GPR) and Falling Weight Deflectometer (FWD) measurements. Computational analyses included the FPS, PerRoad, VESYS, and MEPDG software. The SH 114 design utilized the perpetual pavement concepts, with a thick 1-inch stone-filled layer as the main structural component. This layer was found to be considerably stiffer than the traditional TxDOT mixes. However, this material was also found to be highly permeable and subject to vertical segregation. During construction, the Fort Worth District found it necessary to retrofit edge drains to minimize problems with water trapped in the asphalt layers. For comparison purposes, the Fort Worth District also included a similar section constructed with traditional dense graded mixes. Laboratory and field results from both sections are included in this report. Recommendations are also provided for the structural design of future perpetual pavements in Texas. From the results presented in this project, the current designs are very conservative. The results generated support the transition to higher design moduli for these full-depth pavements.

Accession No. PB2007112703.

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Report Date: February 2007. The use of precast slabs as an alternative to conventional cast-in-place repairs may be an effective means of reducing construction time, thereby minimizing user delay and travel costs while obtaining a long-lasting, durable repair. This report summarizes the 3-year study, Field Trials of Concrete Pavement Product and Process TechnologyPrecast Concrete System for Rapid Repairs, in which precast slabs were used for joint repair and slab replacement on in-service Michigan and Colorado highways. Cast-in-place, full-depth patches were installed as controls. The report contains a summary of the relevant literature; summaries of the field trials and their findings regarding efficiency and durability; recommendations for precast panel installation; a sample distress documentation report; a presentation of construction guidelines; and a sample special provision specification developed as part of the study. Recommendations for consecutive slab repairs are to reduce slab length; use a slab thickness of 200 mm or greater; use dowels to connect precast panels to existing panels for joint flexibility and load transfer; maximize proximity of repair sections when planning and encourage multitasking during panel installation to reduce construction time. For isolated repairs it is recommended that four dowel bars be placed in the wheel path and provide an expansion cap at one end of the dowel bar to accommodate slab movement due to environmental loading and prevent closing of the joint.

Accession No. PB2007113177.

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Report Date: July 2007. This project was designed to develop (1) a better quantitative understanding of the relation between laboratory accelerated binder aging and field aging, (2) a test procedure to measure properties of an aged binder that relate to failure on the road, and (3) a proposed specification for estimating the relative durability of binders in the presence of oxidative aging. Tests were conducted on original base and polymer modified binders, laboratory compacted mixtures, and pavement-aged binders. The project necessarily evolved to a more comprehensive approach to improving pavement service life. Methods for significantly improving pavement durability should be implemented: (1) construct pavements with the lowest possible accessible (interconnected) air voids, consistent with other best construction and mix design practices; (2) use mix designs that have an inherently low decrease in fatigue life with binder oxidation, coupled with an appropriately high initial fatigue life; (3) use binders with a minimum stiffness at the PAV* 16 hour condition (consistent with the appropriate performance grade); (4) use the pavement aging model for pavement design; (5) use binders that have inherently slow hardening rates kinetics; and (6) use modifiers that provide the most reduction in the hardening rate. Items 1 and 2 have a dramatic impact on pavement service life but require additional research for the most effective implementation: (1) determine the parameters that govern the decline of mixture fatigue life with binder hardening; (2) determine methods to reliably, and with minimal risk to other construction parameters, achieve very low accessible air voids in pavements.

Accession No. PB2007114491.

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Report Date: August 2007. This brief summary report documents the main findings from the work done in the last fiscal year. This summary report is composed of three major components: (1) Overlay Tester for crack sealants and associated draft test protocol, (2) repeatability of Overlay Tester for crack sealant, and (3) sensitivity of Overlay Tester for crack sealant. Finally, this report discusses the work recommended by the Pavement Monitoring Committee on October 11, 2006.

Accession No. PB2007114494.

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Report Date: August 2007. This report documents the Type F mix design for Pumphrey Drive, Westworth Village, Fort Worth.

Accession No. PB2007114496.

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Report Date: 2007. The Phase II will involve large scale field-testing of the night vision system in a construction zone to determine its effectiveness with regard to improvement in driving conditions, traffic flow, improved safety, and motorists' perception of the nighttime vision system. A stretch of construction barriers (approximately four miles) will be equipped with the new lighting system followed by sections of unlighted barriers. When a lighted area is followed by an existing (unlighted) segment, and then followed by a lighted area, motorists will be able to compare the effectiveness of the new technology against passive reflectors that are commonly used along the barriers. Four primary methods that have been cited in the literature to study human factors as they relate to traffic accidents and safety are: accident statistics, observational studies, simulated driver studies, and self-report measures. Accident statistics will be determined through data bank of Arkansas State Police. Average speed and traffic flow will be measured electronically for the lighted and unlighted area during the period of intervention. Approximately hundred students from different age and gender groups will be recruited from the university to drive through the test zone at night and participate in a written survey. Subjects will be asked for their perceptions concerning any benefit or decrement to traffic safety due to the addition of barrier lighting, and the degree to which they rely on the visual cues provided by the lights in making driving decisions, as compared with other types of cues. Qualitative data will also be gathered through a questionnaire from the highway travelers who commonly travel in that construction area. They will be contacted to receive their feedback through a questionnaire and an electronic sign will be posted to alert them to the survey. Other methods to be used are: UALR's FacFocus service to receive faculty and student input electronically from those who travel in that area; input from highway construction worker and highway patrol officers through a questionnaire; and possibly use of an 800 number for travelers to call in their comments to a voice recorder. Dr. John Faucett, Associate Professor of Psychology at University of Arkansas at Little Rock, will assist the PI in developing the assessment instruments and in the evaluation of data.

Accession No. PB2007109634.

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Report Date: 2007. With an increased focus on safety, the U.S. DOT, specifically FHWA, has developed new safety analysis tools to help state departments of transportation identify safety problems and potential countermeasures to increase the safety of their highways. Consequently, the development of the safety analysis tools has introduced a new set of requirements for safety data, such as detailed road design data and comprehensive traffic volume data. Safety data are no longer merely crash data, but rather a system of interconnected databases featuring roadway characteristics, roadside features, traffic operations, and driver and vehicle history in addition to crash data. Unfortunately, many states currently lack the database elements and linkages between databases to compile the data sets required by the new analysis tools, which can limit the states' ability to make informed decisions regarding allocation of scarce safety funds.

Accession No. PB2007111520.

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Report Date: February 2007. A commonly used method to delineate lane lines on Virginia's highway pavements is a combination of reflective tape and snowplowable raised pavement markers (SRPMs). The SRPM system consists of a reflective lens epoxied into a plow deflector. The deflector is typically an H-shaped protective steel or cast-iron casting that consists of a pair of parallel keels and a connecting web. The entire system weighs approximately 6 pounds. While this arrangement is thought to improve the visibility of lane lines during darkness and inclement weather, there are questions as to whether the SRPMs can become damaged or detached from the pavement after prolonged exposure to traffic and snowplows. In Virginia, there is no formalized method or schedule for routinely inspecting these markers. They are often examined only when repaving or restriping is scheduled. In April 2006, a SRPM fragment went through the windshield of a van traveling on I-95 in Prince William County, striking a passenger. In response to this incident, a statewide study was initiated to determine if there were any potential problems with SRPMs becoming damaged or detached on Virginia's interstates. Casting condition, reflector condition, epoxy condition, and installation adequacy were inspected on 78 1-mile segments of interstate pavement containing SRPMs. The focus of the study was on sections of pavement that were at least 5 years old and carried current year traffic volumes greater than 15,000 vehicles per day. The study found that nearly 8 percent of all SRPM castings inspected were either missing or damaged. Approximately 35 percent of reflectors inspected were either missing or damaged.

Accession No. PB2007111535.

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Report Date: April 2007. Courts in California may offer drivers cited for traffic violations the opportunity to attend a traffic violator school (TVS) in lieu of conviction. Those who return to the court with proof of course completion have their citations dismissed and masked from public inspection. Because there is no conviction of a violation, these TVS drivers do not have negligent-operator (neg-op) points added to their driving records by the California Department of Motor Vehicles (DMV). The number of drivers attending TVS courses has been increasing. For example, in year 2005, approximately 1,233,327 drivers completed a TVS course as compared to 939,719 drivers completing a TVS course in 1996, an increase of 31%. TVS dismissals represent about 25% of the total number of traffic violation abstracts reported to the department by the courts.

Accession No. PB2007111538.

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Report Date: March 2007. This report provides documentation for UMTRIs file of Trucks Involved in Fatal Accidents (TIFA), 2004, including distributions of the code values for each variable in the file. The 2004 TIFA file is a census of all medium and heavy trucks involved in a fatal accident in the United States. The TIFA database provides coverage of all medium and heavy trucks recorded in the Fatality Analysis Reporting System (FARS) file. TIFA combines vehicle, accident, and occupant records from FARS with information about the physical configuration and operating authority of the truck from the TIFA survey.

Accession No. PB2007112687.

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Report Date: February 2007. The Motor Carrier Management Information System (MCMIS) Crash file has been developed by the Federal Motor Carrier Safety Administration (FMCSA) to serve as a census file of trucks and buses involved in traffic crashes meeting a specific crash severity threshold. Each state is responsible for identifying cases that meet the MCMIS Crash file criteria and reporting the required data through the SafetyNet system. UMTRI has completed a set of evaluations of state reporting and found that reporting rates range from over 80 percent to less than 10. The present report provides a method of predicting, given a known number of fatal involvements, the number of crash involvements a state should be reporting. In each state, the number of fatal involvements is well-known, so all states will start with a known quantity, the number of fatal truck and bus crash involvements. It is then hypothesized that the ratio of reportable crash severities, that is, the ratio of fatal involvements to nonfatal involvements, will apply across all the states. Data from eight states that provide all the information necessary to identify MCMIS-reportable cases were used. A weighted log-linear model is fit to MCMIS data for the eight states that have information recorded for both fatal and nonfatal crashes. The model is then used to estimate the number of nonfatal crashes for a new state in which only the number of fatal crashes is known. Prediction intervals are presented.

Accession No. PB2007112690.

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Report Date: February 2007. This report is part of a series evaluating the data reported to the Motor Carrier Management Information System (MCMIS) Crash File undertaken by the Center for National Truck and Bus Statistics at the University of Michigan Transportation Research Institute. The earlier studies showed that reporting to the MCMIS Crash File was incomplete. This report examines the factors that are associated with reporting rates for the state of Nebraska. MCMIS Crash File records were matched to the Nebraska Crash file to determine the nature and extent of underreporting.

Accession No. PB2007112691.

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Report Date: April 2007. This document presents aggregate statistics on trucks involved in traffic accidents in 2003. The statistics are derived from the Trucks Involved in Fatal Accidents (TIFA) file, compiled by the University of Michigan Transportation Research Institute. The TIFA database provides coverage of all medium and heavy trucks recorded in the Fatality Analysis Reporting System (FARS) file. TIFA combines vehicle, accident, and occupant records from FARS with information about the physical configuration and operating authority of the truck from the TIFA survey.

Accession No. PB2007112692.

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Report Date: March 2007. This report is part of a series evaluating the data reported to the Motor Carrier Management Information System (MCMIS) Crash File undertaken by the Center for National Truck and Bus Statistics at the University of Michigan Transportation Research Institute. The earlier studies showed that reporting to the MCMIS Crash File was incomplete. This report examines the factors that are associated with reporting rates for the state of South Dakota. MCMIS Crash File records were matched to the South Dakota Crash file to determine the nature and extent of underreporting.

Accession No. PB2007112694.

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Report Date: July 2007. A direct observation study was conducted in Spring 2007 to evaluate the statewide 'Click It or Ticket' (CIOT) safety belt mobilization in Florida. The study consisted of two survey waves: a baseline wave completed before CIOT activities began, and a follow-up survey completed immediately following the termination of the activities. Both survey waves were conducted statewide on front-outboard motor vehicle occupants traveling in four vehicle types (cars, vans, SUVs, and pickup trucks). Belt use was estimated for all vehicle types combined (the statewide safety belt use rate) for each survey wave. Additional analyses were conducted to determine belt use rates by several occupant and environmental characteristics. Statewide safety belt use was 74.1 percent prior to the mobilization campaign, and 74.2 percent during the follow-up survey wave. These rates were not significantly different from one another. The study results suggest that the CIOT efforts implemented in Florida during 2007 did not have their intended effect.

Accession No. PB2007112695.

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Report Date: August 2007. The Federal Motor Carrier Safety Administration (FMCSA) has the primary federal responsibility for reducing crashes involving large trucks and buses. FMCSA uses its 'SafeStat' tool to target carriers for reviews of their compliance with the agency's safety regulations based on their crash rates and safety violations. As requested, this study reports on (1) the extent to which FMCSA's policy for prioritizing compliance reviews targets carriers with a high risk of crashes, (2) how FMCSA ensures compliance reviews are thorough and consistent, and (3) the extent to which FMCSA follows up with carriers with serious safety violations. To complete this work, GAO reviewed FMCSA's regulations, policies, and safety data and contacted FMCSA officials in headquarters and nine field offices. By and large, FMCSA does a good job of identifying carriers that pose high crash risks for subsequent compliance reviews, ensuring the thoroughness and consistency of those reviews, and following up with high-risk carriers.

Accession No. PB2007112729.

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Report Date: March 2007. The September 11(or 9/11), 2001, attacks on the high-profile workplaces of the World Trade Center (WTC) in New York City and the Pentagon in the Washington, D.C. area, made real the impact of an unexpected, or no-notice, event in a metropolitan setting. The news coverage of the events of 9/11 showed thousands of people leaving the area of the WTC on foot. The evacuation from the borough of Manhattan included not only the typical traffic congestion expected in an evacuation in the United States, but thousands of pedestrians moving along with, or among, the vehicles. When a large-scale, damaging event has occurred or the imminent threat of one has become known, transportation agencies working with public safety officials have traditionally had two principal objectives: Minimize the time it takes to get an adequate force of emergency responders to the scene where they can help victims, provide assessments, and control access. Maximize the proportion of the population moved away from the hazardous area without being subjected to other risks (e.g., traffic accidents; prolonged exposure to the danger). Evidence that large numbers of pedestrians may be part of an evacuation raised questions within the Federal Highway Administration (FHWA) about what actions are needed to manage pedestrian traffic during metropolitan evacuations and what FHWA can contribute in this area to ensure safe and effective movement of pedestrians while minimizing their impact on vehicular movement.

Accession No. PB2007114039.

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Report Date: 2007. Three videotapes on the profession of civil engineering were produced in 1996 under a grant from MBTC. The objectives were to educate children about professions in transportation and civil engineering in an interesting, age-appropriate way as well as to help educators explain the role of civil engineers in our society. The tapes have been widely disseminated and very well received. Although the objectives of producing the videotapes have been met, the tapes provide only a quick look at the profession. Moreover, elementary teachers and counselors may find it challenging to incorporate the content of the videos into more formal classroom activities. Thus, the proposed project will develop materials to increase the usefulness of the two videotapes directed to K-8 students. Materials may include an internet site, reference and descriptive documents, science projects, math exercises, displays, coloring books, or similar items. Two types of materials will be developed. First, descriptive information will be prepared on such topics as civil engineering sub-disciplines, potential employers, types of employment, academic requirements, and professional organizations. Second, classroom materials will be developed that apply engineering principles and knowledge, such as projects, homework assignments, and coloring books. These documents will give students a better sense of what it takes to become a civil engineer as well as an insight into the challenges and rewards of the profession.

Accession No. PB2007109620.

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Report Date: 2007. The Center for Advanced Transportation Systems Simulation, known as CATSS, was established with the theme of applying advanced technologies to enhance the planning, design, operation, management, and safety of transportation systems. It is the goal of the center to provide cutting edge research, education, and development in the field of surface transportation simulation. The objective of the center is to bring researchers and educators from a wide range of disciplines together to apply large-scale high performance computational capabilities, computer visualization capabilities, and sound experimental capabilities in human factors, to achieve major advancements in transportation systems simulation.

Accession No. PB2007111506.

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Report Date: July 2007. This report summarizes the findings of the Advanced Quality Systems Workshop held in Washington D.C. in November of 2006. The workshop was sponsored by the FHWA and brought together a number of key quality researchers and practitioners. The objective of the workshop was to generate discussion on what exactly constitutes an Advanced Quality System and how to best advance State highway agency quality systems. During the workshop, a definition of Advanced Quality Systems was created. It is important to note that, for State highway agencies, an Advanced Quality System includes both design quality assurance and construction quality assurance. The two are part of the same system. They must not work independently but should be consistent in communicating to the contractor the quality/performance of construction that the State highway agency wants. Continuous improvement in construction quality can best occur when State highway agency construction personnel have a good understanding of the design, especially the design assumptions regarding construction quality, and when they also provide the necessary construction quality feedback to the designers.

Accession No. PB2007112617.

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Report Date: 2007. The Federal Highway Administration (FHWA) provides high-quality information to serve government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Accession No. PB2007113801.

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Report Date: February 2007. Testing Plans for Transportation Management Systems: A Technical Handbook to provide direction, guidance, and recommended practices for test planning, test procedures, and test execution for the acquisition, operation, and maintenance of transportation management systems and ITS devices.

Accession No. PB2007114040.

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Report Date: February 2007. Testing Plans for Transportation Management Systems: A Technical Handbook to provide direction, guidance, and recommended practices for test planning, test procedures, and test execution for the acquisition, operation, and maintenance of transportation management systems and ITS devices.

Accession No. PB2007114041.

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Report Date: January 2007. The System Engineering for Intelligent Transportation System guide is intended to introduce you to systems engineering and provide a basic understanding of how it can be applied to planning, designing, and implementing intelligent transportation systems (ITS) projects. The guide leads you step by step through the project life cycle and describes the systems engineering approach at each step. It describes how to begin implementing the systems engineering approach on your next ITS project and incorporate it more broadly into your organization's business processes and practices.

Accession No. PB2007114042.

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Report Date: August 2007. This report summarizes analysis of Oregon Department of Transportation (ODOT) methods of insourced and outsourced project delivery using data obtained from ODOT reporting systems, ratings of project effectiveness by ODOT Area Managers and by construction contractors, and interviews with ODOT Area Managers and managers from engineering consulting firms that ODOT uses for outsourced design-bid-build projects. Results of a literature review and DOT survey were published in an interim report in December 2003. Guidelines, including a decision tree, are provided for assignment of projects for insourced design-bid-build, outsourced design-bid-build, or design-build delivery.

Accession No. PB2007114499.

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Report Date: June 2007. The first study evaluates the operation and safety of a 120-mile section of I-81 from milepost 80 to 200 (termed the Study Area) in the state of Virginia. The study demonstrated that, apart from five sections along the entire I-81 corridor in the state of Virginia, the operational characteristics are within the design level-of-service C. in terms of safety, the data suggest that the fatal crash rate along the Study Area does not appear to be higher than the national rate for similar interstate facilities. In addition, the data do not suggest any non-fatal crash safety hazards along the Study Area or for any of the Study Area segments. Furthermore, the data suggest that Study Area experiences an injury and property damage crash rate that is lower than the national average rate. The second study describes the TruckWIM framework for modeling vehicle motion along roadway sections by considering both the longitudinal and lateral forces acting on a vehicle. In doing so, the tool reflects the impact of horizontal and vertical alignment on a vehicle's longitudinal motion. The model is capable of reading Global Positioning System (GPS) (longitude, latitude, and altitude), roadway, and vehicle data. The paper demonstrates the validity of the software modeling procedures against field data and the Highway Capacity Manual (HCM) procedures. It is anticipated that by automating the design procedures and considering different vehicle and roadway characteristics on truck motion, the TruckSIM software will be of considerable assistance to traffic engineers in the design of roadways. The third study evaluates a number of lane management strategies along one of the most highly traveled roadway sections of I-81 in the State of Virginia using the INTEGRATION traffic simulation software.

Accession No. PB2007109647.

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Report Date: March 2007. This report summarizes and provides recommendations for quality control procedures to be used for archived data that have been collected and saved by traffic operations systems. This report summarizes quality control procedures used in numerous archived data management systems (ADMS) implementations. This report provides recommendations for a basic set of quality control procedures that can be adopted, as well as a process to customize quality control procedures for system-specific data quality issues. This report also details the typical steps involved in quality control procedures, including the automation of quality checks, the use of manual visual review, the flagging of failed data records, and the use of metadata to document quality control actions. The intended audience for this report includes developers of ADMS as well as researchers and analysts of archived data. Software developers can adapt some or all of the quality control procedures as deemed necessary. The report could also be used or specified in writing a request for proposals to develop an ADMS. Researchers and data analysts can use the report to perform additional quality control if data quality remains an issue.

Accession No. PB2007113178.

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Report Date: November 2006. REDARS (Risks from Earthquake DAmage to Roadway Systems) is a software program for deterministic and probabilistic seismic risk analysis of highway systems. This report documents the base data, research, modeling assumptions, and user requirements for running the REDARS Import Wizard, a software program for importing data into REDARS. Given the dependence on data provided in a standard, federally mandated format, the Import Wizard is limited in flexibility; however, this is addressed in detail in one of the sections. Data sources and critical steps required to develop a REDARS database are documented in a data flow diagram and data models. Appendices are devoted to frequently asked questions, a detailed outline of the programming steps, FHWA network data fields referenced by the Import Wizard, and a list of REDARS data table fields.

Accession No. PB2007114766.

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Report Date: February 2007. This study investigates the potential effectiveness of signal timing at 130 intersections located on five corridors in southeast Michigan. Effectiveness is measured in terms of reduced numbers of crashes after signal timing was introduced. Five years of Michigan crash data from 2001 through 2005 were used to count crashes both before and after signal timing. For each of the 130 intersections, crash sites were geographically located on maps using a spatial analysis software tool and summary crash statistics were provided for injury severity, time of day, day of week, and crash type. In total, there were 12,438 crashes on the 130 intersections. Approximately 80 percent of these crashes resulted in property damage only, and about half were rear-end type crashes. A before-after statistical model was developed to assess the effects of signal timing on the numbers of crashes after the intervention.

Accession No. PB2007112688.

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Report Date: February 2007. This appendix contains maps of geographically located crashes at 130 intersections on five corridors located in southeast Michigan both before and after signal timing. The intersections are grouped according to corridor. The corridors include Ford Road (M153, 26 intersections), Plymouth Road (Old M14, 18 intersections), Jefferson Avenue (10 intersections), Hall Road (M59, 28 intersections), and Woodward Avenue (M1, 48 intersections). The Michigan Crash data cover years 2001 through 2005. Dates of signal timing along with before days and after days are provided for each map. In addition, comparative statistics showing distributions of injury severity, time of day, day of week, and crash type before and after signal timing are shown.

Accession No. PB2007112689.

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Report Date: March 2005. The conventional approach to signal timing optimization and field deployment requires current traffic flow data, experience with optimization models, familiarity with the signal controller hardware, and knowledge of field operations including signal timing fine-tuning. Developing new signal timing parameters for efficient traffic flow is a time-consuming and expensive undertaking. This report examines various cost-effective techniques that can be used to generate good signal timing plans that can be employed when there are insufficient financial resources to generate the plans using conventional techniques. The report identifies a general, eight-step process that leads to new signal plans: (1) Identify System Intersections; (2) Collect and Organize Existing Data; (3) Conduct a Site Survey; (4) Obtain Turning Movement Data; (5) Calculate Local Timing Parameters; (6) Identify Signal Groupings; (7) Calculate Coordination Parameters; and (8) Install and Evaluate New Plans. The report examines each of these steps and identifies procedures that can be used to minimize costs in each step. Special emphasis is placed on the costs of turning movement counts. The report develops a tool box of procedures and provides examples of how the tool box can be used when there is a moderate signal timing budget.

Accession No. PB2007114038.

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Report Date: July 2007. This project recognizes the disparity in the relationship between truck and passenger car speeds and current advisory speed signing practices. The results of this project provide a mechanism that traffic engineers may use to provide enhanced differential warning to trucks and passenger vehicles at freeway connector ramps. Considering the strong evidence that there is a significant differential between speeds that cars and heavy trucks can comfortably and safely traverse freeway connector ramps, there was a need for further research to investigate current advisory speed signing practices and examine whether a dual-advisory speed signing scheme, one that provides different recommended advisory speeds for trucks and passenger vehicles, can safely address this differential. Based on the results of the analysis of average and 85th percentile speeds at the midpoint of each study curve, the dual-advisory warning signs generally had a positive impact on reducing speeds at the point of curvature on the curve and/or having an accompanying reduction in speed-related crashes at the study sites.

Accession No. PB2007114492.

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Report Date: August 2007. TxDOT research project 0-4421 A Simplified Approach for Selecting Optimal Traffic Responsive Control Parameters developed procedures and guidelines for setting up and operating coordinated systems with the traffic responsive plan selection (TRPS) mode. This project implemented the TRPS mode at four locations in Texas using customized versions of the guidelines developed in research project 0-4421. Customization of the guidelines was necessary to account for the differences in certain site characteristics (e.g., available system detectors) between the implementation sites and the general site for which the original guidelines were developed. Locations were selected to represent a range of traffic conditions, arterial and detector configurations, and the two common controller types (Eagle and Naztec) used by TxDOT. The performance of the TRPS mode was evaluated by a comparison of average instantaneous and link speeds and delays determined before and after the implementation of the traffic responsive control. The before-after analyses indicated that the performance of the TRPS mode was in most cases better or at least as good as the existing systems. A step-by-step field manual to guide field technicians through the process of configuring their controllers to run a TRPS control was also developed and delivered to TxDOT to facilitate the implementation of the TRPS guidelines.

Accession No. PB2007114495.

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