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McCormack,E. D. WA-RD 607.1 Options for Benchmarking Performance Improvements Achieved from Construction of Freight Mobility Projects 2005 TRAC/UW
Abstract:
This report documents the development of data collection methodologies that can be used to cost effectively measure truck movements along specific roadway corridors selected by transportation agencies in Washington State. The intent of this study was to design and test methodologies that could be used to measure the performance of freight mobility roadway improvement projects against benchmarks, or selected standards, that would be used both as part of the project selection process and to report on speed and volume improvements that resulted from completed freight mobility projects. One technology tested was Commercial Vehicle Information System and Networks (CVISN) electronic truck transponders, which are mounted on the windshields of approximately 20,000 trucks in Washington. By using software to link the transponder reads from sites anywhere in the state, the transponder-equipped trucks could become a travel-time probe fleet. The second technology tested involved global positioning systems (GPS) placed in volunteer trucks to collect specific truck movement data at 5-second intervals. With GPS data it was possible to understand when and where the monitored trucks experienced congestion and to generate useful performance statistics. The study found that both data collection technologies could be useful; however, the key to both technologies is whether enough instrumented vehicles pass over the roadways for which data are required. This basic condition affects whether the technologies will be effective at collecting the data required for any given benchmark project. The report also recommends the traffic data that should be collected for a benchmark program and the potential costs of using either data collection technology.

Authors:
McCormack,E. D., Hallenbeck,M. E.

Keywords:
agencies, commercial vehicle, condition, congestion, construction, corridors, cost, costs, data, data collection, design, development, freight, freight mobility, freight movement reliability, global positioning, global positioning systems, GPS, improvement, methodology, mobility, networks, performance, positioning, probe program, project, research, roadway, software, speed, statistics, Study, System, systems, technology, traffic, traffic data, transportation, travel time, truck, truck monitoring, trucks, volume, Washington, Washington state


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External Links:
http://www.wsdot.wa.gov/research/reports/fullreports/607.1.pdf http://wsdot.wa.gov/Research/Reports/600/607.1.htm
Al-Yagout,M. A. WA-RD 600.1 Improving Traffic Characterization to Enhance Pavement Design and Performance: Load Spectra Development 2005 TRAC/UW
Abstract:
This research addresses the understanding of, and need for, load spectra in future pavement design procedures and as a stepping stone toward more complete pavement design. The primary objective of this project was to develop truck axle load spectra for Washington State. To do this, axle load data collected at WIM stations throughout Washington State were used. The developed load spectra encompass the principal truck axles on the roadway network: single, tandem, and tridem. Achieving this objective allows the Washington State Department of Transportation, or any state highway agency with analogous traffic patterns, to accommodate the requirements of the 2002 Design Guide, developed through NCHRP Project 1-37A. A secondary objective of this project was to determine whether ESALs obtained from the developed load spectra are significantly different from historical values. Because the developed load spectra are transformable to ESALs, state highway agencies that decide not to use the new guide can still choose to employ the ESALs produced with the load spectra. The project concluded that the developed load spectra are reasonable. For single axles they are comparable to the 2002 Design Guide and MnROAD defaults. For tandem and tridem axles, they are slightly more conservative than defaults of the 2002 Design Guide and MnROAD, but they are still within reason. In addition, the ESALs per vehicle class associated with the developed load spectra are comparable to Washington State historical ESALs for vehicle classes 9, 10, and 13. The use of the newly developed ESALs per vehicle will generally increase design ESALs, but that increase will be due to inclusion of the less predominant vehicle classes (4, 6, 7, 8, and 11).

Authors:
Al-Yagout,M. A., Mahoney,J. P., Pierce,L., Hallenbeck,M. E.

Keywords:
agencies, axle, data, design, developed, development, equivalent single axel load, ESAL, highway, load spectra, pavement, pavement design, performance, project, research, roadway, single axle, traffic, transportation, truck, Washington, Washington state, weigh-in-motion, WIM


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External Links:
http://www.wsdot.wa.gov/research/reports/fullreports/600.1.pdf http://wsdot.wa.gov/Research/Reports/600/600.1.htm
McCormack,E. D. Options for Benchmarking Performance Improvements Achieved from Construction of Freight Mobility Strategic Investment Bo... 2004 TRAC/UW
Abstract:
This report documents the development of data collection methodologies that can be used to cost effectively measure truck movements along specific roadway corridors selected by the Freight Mobility Strategic Investment Board (FMSIB.) The intent of this study was to design and test methodologies that could be used to measure the performance of freight mobility roadway improvement projects against benchmarks, or selected standards, which would be used both as part of the project selection process and to report on speed and volume improvements that resulted from completed FMSIB projects. One technology tested was Commercial Vehicle Information System and Networks (CVISN) electronic truck transponders, which are mounted on the windshields of approximately 20,000 trucks traveling in Washington. These transponders are used at weigh stations across the state to improve the efficiency of truck regulatory compliance checks. By using software to link the transponder reads from sites anywhere in the state, the transponder-equipped trucks could become a travel time probe fleet. The second technology tested involved global positioning systems (GPS) placed in volunteer trucks recruited for this project to collect specific truck movement data at 5-second intervals. With GPS data it was possible to understand when and where the monitored trucks experienced congestion. By aggregating this information over time, it was possible to generate performance statistics related to the reliability of truck trips, and even examine changes in route choice for trips between high volume origin/destination pairs. The study found that both data collection technologies could be useful; however, the key to both technologies is whether enough instrumented vehicles pass over the roadways for which data are required. This basic condition significantly affects whether the transponder and GPS technologies will be effective at collecting the data required for any given FMSIB benchmark project . The report also recommends the traffic data that should be collected for a benchmark program and the potential costs of using either data collection technology.

Authors:
McCormack,E. D., Hallenbeck,M. E.

Keywords:
freight movement reliability, truck monitoring, development, data, data collection, methodology, cost, truck, roadway, corridors, freight, freight mobility, mobility, design, performance, speed, volume, commercial vehicle, networks, trucks, Washington, software, travel time, probe, global positioning, global positioning systems, positioning, systems, GPS, congestion, statistics, reliability, condition, traffic, traffic data, program, costs


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Kopf,J. WA-RD 592.1 Reflectivity of Pavement Markings: Analysis of Retroreflectivity Degradation Curves 2004 TRAC/UW
Abstract:
The intent of this project was to develop retroreflectivity degradation curves for roadway pavement markings. To accomplish this objective, this study utilized a vehicle-mounted Laserlux retroreflectometer to take measurements on approximately 80 test sections throughout Washington state. The resulting retroreflectivity values from roadways with similar average annual daily traffic (AADT) and environments displayed a significant amount of variability. Best-fit trendlines were extrapolated to determine when each category of paint would fall below a selected minimum threshold of 100 mcd/m2/lux and require repainting.Unfortunately, given the variability of the data observed to date, it may not be possible, even with the collection of more data, to create striping performance predictions that have a high level of statistical confidence. According to that schedule, long line painted markings should be painted at least once a year, and heavy wear, long line pavement markings should be painted at least twice a year.

Authors:
Kopf,J.

Keywords:
degradation curves, Laserlux retroreflectometer, pavement, pavement markings, retroreflectivity, roadway, Washington, Washington state, traffic, environment, data, performance, prediction, line


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External Links:
http://www.wsdot.wa.gov/research/reports/fullreports/592.1.pdf http://wsdot.wa.gov/Research/Reports/500/592.1.htm
Chayanan,S. WA-RD 562.1 Interaction Between the Roadway and Roadside--An Econometric Analysis of Design and Environmental Factors Affecting Segm... 2003 TRAC/UW
Abstract:
The purpose of this research was to explore the relationship between roadway and roadside accidentrates for Washington State highways to improve the Washington State Department of Transportation's(WSDOT) process of modeling roadway and roadside accident rates and to arrive at possible improvements in the efficiency of WSDOT's safety project programming process.The project tested the use of the seemingly unrelated regression estimation (SURE) model to modelthe roadway and roadside simultaneously. The theoretical advantage of the SURE approach is that it does not impose any a priori assumptions on the explicit linkage between roadway and roadside accident rates, and there is no theoretical support for explicit linkage, either. The data used to derive this model were from a random sample of 500 one-mile sections from the Washington State highway system. Traffic dataincluded traffic volumes, truck compositions, AADT, traffic speeds, and other relevant information.Geometric data included lane, shoulder, median, curve, and intersection information. Historical weather data such as monthly precipitation and temperature were collected from the National Oceanic and Atmospheric Administration database.In comparing significant explanatory variables between the roadway accident rate and roadsideaccident rate models, very few variables were common. This confirms that it is preferable to specifyseparate functional forms for roadway and roadside accident rates. Empirical results indicated thatcorrelation between roadway and roadside accident rates was insignificant, indicating that efficiency gainsfrom the SURE model would be minimal. The important finding from a programming standpoint is thatjointly modeling the roadway and roadside simultaneously would not result in significant efficiencyimprovements in comparison to the current state-of-the-practice in Washington State.

Authors:
Chayanan,S., Nebergall,M., Shankar,V., Juvva,N., Ouyang,Y.

Keywords:
roadway, roadside, accident rates, safety programming, research, Washington, Washington state, highway, transportation, WSDOT, modeling, safety, regression, linkage, data, traffic, traffic data, volume, truck, speed, median, temperature, database, models


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External Links:
http://www.wsdot.wa.gov/research/reports/fullreports/562.1.pdf http://wsdot.wa.gov/Research/Reports/500/562.1.htm
Herman,L. A. WA-RD 327.1 Noise Mitigation Strategies - Final 454 1993
Abstract:
Noise mitigation strategies involving both noise reduction at the source of transportation noise and at the receiver of transportation noise are reviewed. The following major sources of noise within a motor vehicle considered: engine, intake, exhaust, cooling fan, transmission, and tire noise. Current research intended to address methods of reducing noise far each of these sources is discussed. It was found that vehicle manufacturer efforts in the U.S. to reduce vehicle noise is currently being motivated marketplace for quiet vehicles. In addition to the potentialnoise reduction from specific components of the vehicle, it was found that the type of roadway pavement can have a significant effect on noise. A key strategy for reducing transportation noise at the receiver of the noise is land use compatibility planning. local agencies who have successfully implemented and use compatibility planning programs were interviewed. These programs fall into two broad The first category is land use compatibility brought about by zoning. this category, land uses that are inherently with transportation noise sources are adjacent to the sources. The second category, referred to as proponent mi involves a process of mitigation needed to make the use with transportation noise through mitigation efforts funded by the proponent of the development. It was found that noise and land use compatibility programs were most beneficial to communities in the earlier stages of development whereas the use of a local noise ordinance was found to be more beneficial to communities that are more fully developed.

Authors:
Herman,L. A., Bowlby,W.

Keywords:
agencies, developed, development, land use, land use compatibility, land-use, methods, mitigation, noise, noise abatement, noise barriers, noise reduction, pavement, planning, program, research, roadway, tire, tire noise, traffic noise, transportation, vehicle noise, zoning


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Herman,L. A. WA-RD 327.2 Noise Mitigation Strategies - Technical 455 1993
Abstract:
Noise mitigation strategies involving both noise reduction at the source of transportation noise at the receiver of transportation noise are reviewed. The following major sources of noise within a motor vehicle were considered: engine, intake, exhaust, cooling fan, transmission, and tire noise. Current research intended to address methods of reducing noise far each of these sources is discussed. It was found that vehicle manufacturer efforts in the U.S. to reduce vehicle noise is currently being motivated marketplace for quiet vehicles. In addition to the potential noise reduction from specific components of the vehicle, it was found that the type of roadway pavement can have a significant effect on noise. A key strategy for reducing transportation noise at the receiver of the noise is land use compatibility planning. Local agencies who have successfully implemented and use compatibility planning programs were interviewed. These programs fall into two broad categories. The first category is land use compatibility brought about by zoning. In this category, land uses that are inherently with transportation noise sources are adjacent to the sources. The second category, referred to as proponent mitigation, involves a process of mitigation needed to make the use with transportation noise through mitigation efforts funded by the proponent of the development. It was found that noise and land use compatibility programs were most beneficial to communities in the earlier stages of development whereas the use of a local noise ordinance was found to be more beneficial to communities that are more fully developed.

Authors:
Herman,L. A., Bowlby,W.

Keywords:
agencies, developed, development, land use, land use compatibility, land-use, methods, mitigation, noise, noise abatement, noise barriers, noise reduction, pavement, planning, program, research, roadway, tire, tire noise, traffic noise, transportation, vehicle noise, zoning


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Roper,T. H. WA-RD 149.1 Pacific Avenue O\'Xing Evazote 50 Expansion Joint Seal / Bridge #5/332 1990
Abstract:
Bridge expansion joints pose a special problem in the Washington State Department of Transportation (WSDOT) bridge deck management system. These devices are subject to repeated heavy dynamic loading, and premature failure has occurred in many cases. It is WSDOT policy, as part of the Bridge Deck Management System, to make expansion joints watertight in order to reduce the potential of substructure corrosion induced by roadway deicing salts and other contaminants.Expansion joint seals play an important role in keeping expansion joints watertight. A relatively new material, Evazote 50, looks promising in its performance characteristics as an expansion joint seal. It is able to accommodate considerable joint movement, its durability and corrosion resistant properties are excellent, and it is resistant to absorption of oils and greases. The purpose of this experimental project is to gain knowledge about the material\'s effectiveness over time and to gain knowledge about field installation techniques. It was very beneficial to have the manufacturer\'s representative on the job during installation. This was required by special provision and is a practice that should be continued on future projects.In-place performance will determine acceptance of Evazote 50 for general use.

Authors:
Roper,T. H., Henley,E. H. Jr

Keywords:
absorption, bridge, bridge deck, bridge deck rehabilitation, corrosion, Deck, durability, effectiveness, expansion joints, experimental, in-place, ITS, Joints, management, management system, performance, policy, roadway, salt, transportation, Washington, Washington state, WSDOT


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Carr,D. H. WA-RD 194.1 Clear Zones for Local Agencies 1989
Abstract:
The reported study was used to investigate clear zone practices, policies and standards that are employed both within Washington State and throughout the United State. Emphasis was placed on those standards or guidelines that apply to local city and county roadways which are predominately low volume and low speed facilities.The review of nationwide clear zone practices pointed to a need for a set of clear zone guidelines or standards that apply specifically to low volume, low speed facilities. The research also pointed to the need for guidelines or standards that could be easily applied by city or county agencies with limited staff and limited budgets.One of the findings of the research is a step by step format for agencies to use in establishing a program to address existing clear zone deficiencies.

Authors:
Carr,D. H., Curtin,J. J., Dorvel,P. E.

Keywords:
agencies, Clear zone, control zone, counties, facilities, policy, program, recovery area, research, review, roadway, speed, volume, Washington, Washington state


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Ernst,D. D. WA-RD 113.1 Alternative Deicing (CMA Research) 1988
Abstract:
As part of the pooled fund research project, the Washington State Department of Transportation was selected to field-test approximately 100 tons of Calcium Magnesium Acetate (CMA) to evaluate its potential as a deicing chemical with direct comparison to salt (Sodium Chloride) and Urea. Evaluation included all aspects of storage, handling, use, and performance. CMA was applied whenever necessary at each test site, using the same application rates as presently used for salt. Typical equipment consisted of front dump trucks with the spinner ahead of the rear axle, and rear discharge hopper trucks. All equipment was used without modification.The use of CMA at the beginning of a storm reduced the amount of bonding of snow to the roadway surface. This effect of keeping the roadway surface bare for longer periods of time reduced the cost of snow fighting. This was accomplished with chemical application rate of 125 Ibs. per lane mile.The addition of sand to CMA reduced the problems of dust, caking and uneven distribution. The sand provided moisture and weight to the application resulting in a smoother, more even distribution. CMA spread above was excessively dusty creating problems in the spreading and distribution. CMA is slower to react on compact snow and ice than salt or Urea. This delay in reaction time was not considered a handicap in the overall snow fighting procedure.The conclusion was that CMA shows promise as a deicing-melting chemical. The problems of dust, light-weight and brittleness need further work and may be significantly alleviated by development of a hydrated compound.

Authors:
Ernst,D. D.

Keywords:
Alternative, axle, chloride, cost, Deicing (CMA Research), development, evaluation, field test, ITS, lightweight, performance, research, roadway, salt, snow, transportation, truck, trucks, Washington, Washington state, weight


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Toney,C. A. WA-RD 133.1 Fiber Reinforced Asphalt Concrete Pavements 1987
Abstract:
The use of BoniFibers fiber reinforced Asphalt Concrete Pavement (ACP) at three City of Tacoma intersections is reported. Product selection, fiber reinforced ACP mix design, old pavement removal, construction and evaluations are documented.BoniFibers fabric reinforced ACP appears to provide a durable roadway at intersections that have a high volume of turning and heavy traffic. Continued monitoring of the City of Tacoma fiber reinforced ACP is recommended until major deterioration occurs.

Authors:
Toney,C. A.

Keywords:
asphalt, asphalt concrete, Asphalt Concrete pavement, Bonifibers, concrete, construction, design, deterioration, evaluation, fiber Reinforced ACP, fiber reinforced pavement, monitoring, pavement, pavements, Polyester Fibers, Polymar Fibers, roadway, traffic, volume


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Blodgett,F. J. WA-RD 102.1 Changeable Message Sign 1987
Abstract:
A changeable message sign to inform, warn and direct traffic was installed in Vancouver, Washington prior to the initiation of major reconstruction on the Interstate 5 corridor. Despite some operational problems, the sign proved to be of considerable value in informing motorists of the changing roadway configurations necessitated by the construction operations. The use of similar signs in other locations was recommended.

Authors:
Blodgett,F. J.

Keywords:
Changeable message sign, construction, reconstruction, roadway, traffic, Washington


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Public Transportation and Planning Division WA-RD 048.1 Small Car Accident Experience in Washington State 901 1982
Abstract:
This small car accident study investigated accidents in Washington State in four passenger car categories: subcompact, compact intermediate, and large. The primary purpose of the study was to evaluate the effects on safety of increases in the number of smaller cars on the highways. Traffic accident data for the period 1973-79 were analyzed to determine the accident severity for the different automobile classes, and this analysis showed that the smaller vehicles had a higher proportion of fatal and injury accidents that the other categories.The, accident data for 1980 were used to compare accident experience with regard to injury class of the occupants, roadway surface conditions, roadway character, light conditions, collision type, objects struck, and location of accident. Analysis showed that for total accidents per one thousand registered vehicles, the large cars had a higher rate (68) than either the subcompacts (43), compacts (45), or intermediate size vehicles (46). However, the subcompacts and compacts had higher percentages of fatalities and serious injuries to their occupants, and a higher proportion of such accidents occurred on wet, snowy, and icy surfaces. In addition, the smaller passenger vehicles had a higher incidence of overturning and rear-end accidents. The analysis suggests there will be significant increases in fatal and injury accidents in future years as the number of smaller vehicles increases. Thus, the report contains recommendations for changes in highway and vehicle design that will modify these adverse trends and reduce injuries and fatalities among drivers and passengers.Some of the recommendations can be implemented fairly quickly, but others will take longer. However, until changes are made, the accident severity for small cars will continue at a level above that for larger automobiles.

Authors:
Public Transportation and Planning Division

Keywords:
accident severity, accidents, analysis, collision, condition, data, design, highway, Highways, light, overturning, roadway, safety, Study, traffic, traffic accident data, Washington, Washington state


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Whalen,K. WA-RD 040.1 Load Restriction Determination Study 930 1980
Abstract:
The project identified various highway roadways subjected to load restrictions for cataloguing on a District-wide map. An investigation of freeze-thaw events and pavement deflections was conducted in addition to collection of weather data at selected sites. "Frost Tubes" were evaluated and found to be an effectivetool for measuring frost depths. Limited data was collected due to warm winters and short freeze-thaw cycles. It was concluded that load restrictions are not needed until the temperature changes to a warming period. Additional research is needed to determine when load restrictions should be removed.

Authors:
Whalen,K.

Keywords:
data, Freeze Thaw, freeze-thaw, frost, Frost Tubes, Frozen Pavement, highway, load restrictions, pavement, pavement deflection, project, research, roadway, temperature, winter


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Badgley,Franklin WA-RD 012.2 The Selection and Calibration of Air Quality Diffusion For Washington State Highway Resources 1976
Abstract:
At the request of the Washington State Department of Highways a study was conducted to evaluate three computer models specifically designed to predict carbon monoxide concentration at receptor points along roadways. The models were evaluated on their ability to predict values obtained from a monitoring network established along various roadways in the State of Washington. Monitoring consisted of 12 ground level CO stations, meteorological stations and traffic counters. Traffic speeds were sampled for conformity during peak hours. The final selected models, CALINE and EPA's HIWAY were given calibration factors to be used when calculating Receptor Concentrations for Impact Assessments.

Authors:
Badgley,Franklin, Rossana,T. August, Alsid,Hal F., Lutrick,David

Keywords:
air pollution, air quality, Assessment, calibration, carbon monoxide, computer, Computer Modelin, Concentrations, highway, Highways, impact, model, models, monitoring, quality, roadway, speed, traffic, Transportation Pollution Source, Washington, Washington state


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Richey,E. P. WA-RD 013.1 Attenuation of Random Deep Water Waves By Porous Walled Breakwater 1974
Abstract:
The porous walled resonating chamber, a type of breakwater, is investigated as a means of reducing reflected waves from structures subjected to random wind generated waves in deep water. Extending laboratory monochromatic studies to a full-scale apparatus appended to a floating bridge allows assessment of scale factors and the effects of random waves on the predicted performance of thedevice as a linear damped oscillator . The full-scale device is shown to be frequency selective at a frequency precisely corresponding to the predicted resonance of the system. The forces, measured on the porous wall, are lower than predicted and the device completely eliminates the problem of wave runuponto the bridge roadway. The method of evaluating the energy attenuation by the breakwater incorporates spectral analysis of digitized data recorded at fixed locations equidistant in front of the chamber and at a remote station away from the influence of the breakwater. Analysis demonstrates that the time average energy density at a fixed location where incident and reflected waves co-exist is influenced not only by the wave amplitudes, as expected, but also by the product of the amplitudes and a function of the phase angle. The chamber effects a change in the random phase angle during reflection , producing a different effective distance of wave travel to the fixed location and thus negating quantitative analysis of the energy dissipation.

Authors:
Richey,E. P., Morden,D. B., Hartz,B. J.

Keywords:
analysis, Assessment, attenuation, Breakwater, bridge, data, density, Energy, floating bridge, forces, incident, performance, roadway, structures, travel, Wave attenuation, wind


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Klasell,J. A. WA-RD 018.1 Acoustical Barrier Noise Characteristics Research Project, HR 535 HR 475 1974
Abstract:
This study was chiefly aimed at determining if a standard precast concrete median barrier placed on a highway shoulder in a fill section, would be effective in reducing highway traffic noise outside of the roadway prism. Secondly, it attacked the question of whether the current computer noise prediction program was giving accurate values.The first phase of the study consisted of collecting noise and traffic measurements in the field, first without and then with a median barrier, at two selected test sites. Next, the geometry of the test sites and field traffic data were entered into the computer program and the predicted noise levels obtained.The second phase consisted of comparing these two sets of data to determine the accuracy of the computer program and the amount of sound reduction, if any, due to the median barrier.The results indicated that the highway traffic noise was dominated by truck generated noise. It was therefore concluded that a standard median barrier will not provide a significant amount of sound reduction, outside of the roadway prism, when placed on a highway shoulder in a fill section. The results also indicated that the current computer noise prediction program will calculate noise levels that are usually higher than actually exist.

Authors:
Klasell,J. A., Butler,B. W.

Keywords:
Acoustical barrier, barrier attenuation, computer, computer program, concrete, data, ground attenuation, highway, median, median barrier, noise, Noise Levels, precast, precast concrete, prediction, program, research, roadway, traffic, traffic data, traffic noise, truck, wind, wind noise, barrier, project

Foss,Rene N. WA-RD 005.2 Tire Noise Properties And Two Resurfacing Materials Used By Highway Bridges For Repair Of Wear 1014 1972
Abstract:
The purpose of this study was to investigate the acoustic effects of two topping materials used on bridges in the Seattle area. One material was applied to the bridge on Interstate-5 which crosses the Duwamish River. It is an English product called Sprag-Grip which is supposed to have very good anti-skid properties, as well as the ability to stick to the road in thin layers thus making it suitable for the repair of worn surfaces. The other material is an epoxy -asphalt mixture which was applied to some sections of the Evergreen Point Floating Bridge over Lake Washington, particularly over sections where worn grating was causing excessive noise. Hopefully, this substance will be capable of long-term sticking in relatively thin layers. Of the two materials, it was found that the epoxy-asphalt topping on the Evergreen Point Floating Bridge was by far the quieter, and, at least as newly applied, proved to be very quiet at the road/tire interface. It is likely that this good acoustic performance is due to the smoothness of the surface rather than directly to the fact that the material contains epoxy. The role of the epoxy would be as an adhesive and to resist wear so that its original acoustic performance could be maintained for a considerable length of time. Spray-Grip, on the other hand, although slightly quieter than the rutted, worn roadway, was not as quiet as the original unworn road surface. Experimental Procedures The primary contribution of a road surface to the noise 'radiating from a vehicle is in the noise emitted at the road/tire interface; therefore, the major thrust of this effort was directed toward measuring this effect. There also were some measurements of community noise levels before and after the resurfacing of the bridges. The tire noise tests were taken on the right rear wheel of a Laboratory station wagon upon which a new tire was mounted (a Pennsylvania Patrol Special, size 8. 55-15). (The tread design and depth of this tire are shown on page 2. ) This tire was mounted on a wheel and used on the vehicle only daring tests. Between tests it was stored so that unnecessary wear would not change its acoustic character-teristics. The noise pickup device was a specially baffled microphone located about 7 inches from the road/tire interface by a bracket holding it on the outside of the tire. One of the major problems in making noise measurements of this type is to have a microphone that will pick up only tire noise and be baffled from wind noise. This problem has been solved by a microphone baffling system especially designed by this Laboratory.

Authors:
Foss,Rene N.

Keywords:
asphalt, bridge, bridges, community noise, design, Epoxy, experimental, floating bridge, highway, ITS, materials, mixture, noise, Noise Levels, noise measurements, performance, repair, roadway, seattle, Study, System, tests, tire, tire noise, Washington, wind, Wind Noise


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Brands,F. WA-RD 003.1 Pavement deflection Measurement Dynamic (A Feasibility Study) 1025 1970
Abstract:
The objective of this study was to determine the feasibility of developing a device or technique to provide rapid measurement of parameters indicative of roadway condition or structural capacity. Currently existing equipment is inadequate for making meaningful measurements with speed and convenience. Consequently, a new system called "impulse testing" has been proposed and its concepts proved in this study. This system incorporates new techniques of non-destructive testing, and is adaptable to mechanization for automatic operation. The system is based on the deflection of the pavement under impulse loading, and also on the energy propagation characteristics of the pavement. These two parameters are combined to formulate a quantity which is called the impulse index and which has a high degree of correlation with the structural properties of the pavement.

Authors:
Brands,F., Cook,C. J.

Keywords:
condition, Energy, equipment, impulse index, index, ITS, nondestructive testing, pavement, pavement deflection, roadway, speed


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