bluuebunny/crossref_metadata_2025 huggingface dataset:
Baltic States Road Weather Information System Project: Joint Internet Application for the Road User
Authors: Martikainen Päivi , Juntunen Janne
Published: April 2007

The automated road weather information system (RWIS) is used to continuously record the current and predicted status of driving conditions on the road network. By the end of 1999 there were more than 60 road weather stations in the Baltic countries and an additional 275 stations in Finland. The four countries have joined resources to develop a common Internet interface (www.balticroads.net) by which to share the existing RWIS data collected around the Baltic Sea region more effectively with the transport sector and other road users. The overall goal of the Internet interface is to provide better access to accurate road weather information for the transport industry and the driving public, thus resulting in better service and improved traffic safety. The cooperation among the national road administrations improves utilization of the information from the existing RWIS in road maintenance operations. The possibilities to expand the Internet service are endless. It is possible to access the service through an Internet connection at border stations and gas stations, as well as to transfer the data via local radio operators and text-TV providers. The vision is also to extend the Internet service to cover road weather data from the neighboring countries in the Baltic Sea region. The Baltic RWIS Internet interface provides current data on local road weather such as road and air temperature, type of precipitation, road condition, wind speed and direction, and dew point and humidity.
Road Weather Information System in Finland
Authors: Toivonen Kimmo , Kantonen Jouko
Published: April 2007

Weather has a significant impact on winter traffic, directly by causing poor visibility or indirectly by causing poor driving conditions (e.g., slipperiness due to snow, slush, or ice on the road), multiplying the risk of an accident. To decrease accident risk and to improve safety and traffic flow, the Finnish National Road Administration has developed a road weather information system (RWIS), the purpose of which is to provide the road maintenance staff with information about prevailing road and weather conditions on the road network in winter. With the help of this system, road maintenance measures such as salting and plowing can be timed better, and the amount of antislipping agents used can be optimized to a minimum level. Another growing function of the system is to provide information to road users. The system’s operation is based on automated road weather stations equipped with measuring devices. Approximately 270 road weather stations located along the main roads throughout the entire country are currently connected to the system. These stations collect data about air, road surface, and dew point temperatures; wind; humidity; rain; visibility; and surface road conditions. The RWIS retrieves data from the road weather stations every 15 to 60 min. All road weather data are centrally stored in a common, national database. The current status of the Finnish RWIS is described, and plans for the future are discussed.
Do Salting Operations Match Road and Weather Conditions?: Results of Finnish Follow-Up Study
Authors: Raukola Tapio , Terhelä Mika
Published: April 2007

According to the winter maintenance policy of the Finnish National Road Administration (Finnra), a bare pavement policy applies to the busiest main roads (at least 50 percent of the road width must be bare). Finland has approximately 6500 km (4,000 mi) of such roads. Environmental impacts caused by the use of road salt have forced Finnra to develop its salting technology to minimize salt use. Maintaining traffic safety and flows at a high level while reducing the use of salt has proved a challenging task, but new salting technology is helping to achieve the objective. Also, it is essential to know how much salt will be required for different situations. Some years ago Finnra developed a salting table to assist in choosing the proper application rate. How the recommendations of the table have been followed and whether the recommendations of the table were satisfactory were studied on the basis of past Road Weather Information System data. Of 61 study cases, none showed significant failure. The main conclusion of the study was that the recommendations in the table are correct. However, the field staff do not appear to rely on the table sufficiently. Instead, much higher application rates than recommended are often used. Still, the application rates are smaller now than they were 10 years ago. Recommendations for action are given.
Use of Abrasives in Winter Maintenance at the County Level
Authors: Nixon Wilfrid A.
Published: April 2007

The use of abrasives in winter maintenance is a well-established practice. Typically, sand is placed on the road in amounts up to 340 kg/lane-km (1,200 lb/lane-mi). The sand is intended to increase friction between the vehicles and the often snow- or ice-covered pavement. Yet very little information exists on the value of sanding as a winter maintenance procedure. What information does exist tends not to support sanding as a process. Studies suggest that at highway speeds sand is swept off the road by relatively few vehicle passes (8 to 12) and that friction gains from sanding (when the sand remains on the road) are minimal. There are increasing environmental concerns about sanding. Some U.S. cities have already stopped sanding because of air quality concerns. Others are required to clean up all sand as soon as possible after application, using street sweepers. The state of the practice of abrasives usage in Iowa counties is reviewed. On the basis of these practices and the existing studies on abrasives usage, an attempt has been made to categorize the practices into three classifications: appropriate, questionable, and inappropriate. The choice of these categories for each practice is discussed. The classification of practices suggests that significant changes may be needed in regard to abrasives usage in winter maintenance. The nature of these changes is presented and discussed.
Ice Control Technology with 20 Percent Brine on Highways
Authors: Fonnesbech Jens Kr.
Published: April 2007

Saturated brine (20 percent) is used for ice clearing to decrease the use of salt (NaCl) but at the same time maintain or increase the level of drivability and safety. A new technique makes it possible to spread brine from a truck traveling 70 km/h (45 mph) in one lane onto the neighboring lanes. The possibility of decreasing the use of salt by changing the spreading method was studied. In Funen County, 20 percent saturated brine has been used successfully to combat icy roads with frost, ice formation on wet lanes, glaze, and snow. In winter 1998–1999, the residual salt from the spreading of brine and prewet salt was measured in 1,800 places. Results showed that saturated brine is spread more evenly across the road than prewet salt, and more salt from the brine is still present on the road 2 h after spreading as compared with prewet salt. Several statistical analyses were carried out, giving a useful picture of the amount of residual salt on the roadway and indicating that more salt from brine than from prewet salt is active on the roadway and that degradation of residual salt is crucially affected by high traffic intensity. In practice, spreading of saturated brine takes effect immediately if there is frost or ice on the road, whereas dry or prewet salt takes time to become effective. Likewise, it has been shown in practice that saturated brine is effective in glaze and snow conditions, but 20 mL (4.6 g/m2 NaCl) normally is not enough. Use of saturated brine has produced such good results that within the next 10 years Funen County is expected to convert to the sole use of this method of ice clearing. The most common application is expected to be 20 mL/m2 or less, but in special cases it might be necessary to use 40 mL/m2.
Anti-Icing Operations with Prewetted Fine-Graded Salt
Authors: Martinelli Thomas J. , Blackburn Robert R.
Published: April 2007

The Kansas Department of Transportation and the Wisconsin Department of Transportation in cooperation with the Brown and Columbia County Highway Departments conducted a 2-year study of various gradations of road salt used during winter storm events in an anti-icing application. The objectives of the study were to document the advantages of two finer gradations of prewetted salt used during anti-icing operations and to evaluate the ability of current salt spreader equipment to distribute various gradations of salt. The four-task study consisted of laboratory and field testing of various prewetting rates for the different gradations of salt, field observations and documentation of actual winter maintenance activities, analysis of data collected during actual storm events, and reporting of results. Results and conclusions from the 2 years of data collection were limited because only a minimal number of storm events could be documented. The finer gradation of salt did produce a faster salt brine reaction on the pavement, but it did not last as long as the standard gradation of salt, which resulted in more frequent reapplication of the finer gradation of salt.
Getting Passionate About Winter Maintenance Research
Authors: Pletan Rodney
Published: April 2007

The joy of working in a curious and innovative culture is the desire of many governmental organizations. Rules, regulations, and other bureaucratic procedures are often big-time barriers to change in governmental operations. Authorship and ownership of existing methods add to the resistance to change. Budget-conscious superiors often automatically discourage and discard ideas that require investing additional money up front. “If it isn’t made here, we don’t need it” and other syndromes cause the rank and file to continue doing things the same way they always have instead of “fighting city hall.” The Minnesota Department of Transportation (MnDOT) is an exception. There, winter maintenance research has developed beyond just being a program; it is a culture and a way of life. MnDOT is passionate about winter maintenance research. There are several key issues that are important to recognize in MnDOT. The passion resides at the maintenance worker level. Supervisors and top management provide encouragement, support, and guidance and are not stumbling blocks. Dedicated funding fuels innovation. New ideas that generate the most support are those that are customer focused and quality related because the customer is the common denominator that every level in the organization understands. It is hard not to support and fund new ideas that improve the effectiveness of products and services delivered to the end user. Finally, MnDOT has learned that providing opportunities for champions of innovation to share their accomplishments is an outstanding way to maintain and elevate even higher the excitement associated with maintenance research.
Millimeter Wave Radar Technology-Based Intelligent Winter Highway Systems
Authors: Kaneko Manabu , Kajiya Yasuhiko , Matsuzawa Masaru , Konagai Nobuo
Published: April 2007

To help prevent accidents in winter, the Civil Engineering Research Institute of the Hokkaido Development Bureau has been promoting research and development on a safe-driving support system for winter roads. The focus is on millimeter wave radar as a promising technology for detecting obstacles ahead, such as stopped cars, when visibility is reduced by snowstorms. A questionnaire survey on winter roads found the safe-driving support system with millimeter wave radar to be effective for road sections in flat areas, tunnels, intersections, and expressway ramps. Therefore, verification tests were conducted on a test system. Millimeter wave radar effectively detected obstacles on roads where visibility was reduced. For enhanced detection accuracy, a combined millimeter wave radar and infrared camera was developed, and an obstacle detection test was carried out with the integrated system. Collation of data from the radar and the camera, each of which tracks the object independently, reduced the error. The effect of a warning of danger on driving behavior was tested. A reduction in the difference of driving behavior between drivers of different demographic categories was observed when information about the obstacle was provided. This indicates effectiveness in preventing accidents. Additional tests in which subjects were aided by video or computer graphic images confirmed the effectiveness of intelligent, light-emitting delineators in warning drivers.
Performance of Various Antifreezing Pavements by Field Test
Authors: Takeichi Kiyoshi , Sato Iwao , Hara Fumihiro , Yamamoto Chigako
Published: April 2007

Eleven kinds of antifreezing pavement that rely on physical action were tested. The test pavements were compared with conventional pavements. The pavements covered with elastic materials or elastic material mixed with conventional material, both of which rely on surface deflection by the load of passing vehicles to break ice, were found to be more effective than the pavements with a coarse surface. A pavement into which grooves are cut and filled with urethane resin (Test Pavement B3) and a pavement with cylindrical or doughnut-shaped rubber embedded at regular intervals in the surface (Test Pavement B4) had high anti-freezing effectiveness. Based on these results, a model intersection was installed with these two pavement types of high antifreezing effectiveness. A survey of pedestrians at the intersection was conducted. Of the respondents, 45 percent answered that it was easier to walk on these kinds of pavements than on conventional pavement. There was less delay in the starting of automobiles when the traffic light turned green with B3 pavement than with other types of pavement. These results confirm that application of antifreezing pavement is effective for pedestrians and automobiles. Further study should focus on confirming the long-term durability and performance life.
Development and Use of an E-Mail-Based List-Serve for Winter Highway Maintenance
Authors: Nixon Wilfrid A. , Wilson Mark A.
Published: April 2007

At the 4th TRB Symposium on Snow Removal and Ice Control Technology, held in Reno, Nevada, in 1996, it was suggested that some sort of centralized e-mail-based communications system would benefit the winter maintenance community. Later that year, the snow and ice list-serve was established (snow-ice@list.uiowa.edu). The performance of the list-serve in the three years since its formation is reviewed. Membership and message volumes are reported. Messages sent are divided into categories. The mechanics of the list-serve are described, and the procedures for its establishment and maintenance are detailed. There have been changes in procedure since the list’s formation, and these changes are discussed. Problems with the list are also presented and solutions are given. Estimates for the time required to maintain such a list-serve are given, along with details of the software used to establish and maintain the list. Finally, results of a survey of the list of subscribers are presented; on the basis of this, the value of the list-serve to the winter maintenance community is estimated. Information on how to subscribe to and use the list-serve is provided.
Advanced Decision Support for Winter Road Maintenance: FHWA Documentation of Requirements for Intelligent Transportation Systems
Authors: Pisano Paul A. , Nelson Gary G.
Published: April 2007

FHWA created the Road Weather Management Program within the Office of Transportation Operations to develop weather information systems, improve winter maintenance technologies, and improve road weather management practices for all weather threats. The program identified winter road maintenance decision support as a priority. In 1999, the program sponsored the Surface Transportation Weather Decision Support Requirements project to study surface transportation decision making, with a focus on winter road maintenance, and to create an operational concept description (OCD) for an advanced decision-support system to improve the current Road Weather Information System. Described are the findings on winter road maintenance decision making that went into the OCD and the plans for further development of an advanced decision-support application within the Intelligent Transportation System.
Target Luminance in Blowing Snow as a Function of Illuminance Conditions and Visual Range
Authors: Hagiwara Toru , Kajiya Yasuhiko , Akasaka Hitoshi , Matsumoto Yasuyuki , Kobayashi Shoji , Mima Keniti , Imazu Ryuji
Published: April 2007

In strong snowstorms, adequate visibility of road delineators provides the driver with important road geometry cues. Few data have been published on the luminance of targets in snowstorms. A model is proposed with which to determine the luminance of an illuminated delineator and the background luminance in snowstorms. An experiment was performed over 30 days in the Ishikari district in Hokkaido, Japan, in 1997. Luminance, illuminance, and transmissivity in snowstorms were simultaneously recorded by a data-recording system at intervals of 10 min. The observation distance was set at 34 m, and snow on the ground was used as the background. The recorded data indicated that the background luminance in snowstorms was affected by illuminance and transmissivity. A multiple regression equation was applied to the model to determine the background luminance. A black board and an illuminated delineator were used as visual targets at the test site. The data indicated that these luminances could be estimated by the multiple regression equation. Differences of the illuminated delineator and the black board in luminance were calculated from these models if the visual range, the observation distance, and the illuminance were given. For example, at a visual range of 200 m, an illuminance of 5000 lx, and an observation distance of 100 m, contrast of the black board was five times greater than that of the illuminated delineator. The results of the study showed that the illuminated delineator indicated good visibility during snowstorms in dark conditions, whereas the black board had a better visibility than the illuminated delineator during snowstorms in the daytime. An illuminated delineator should be located close to the driver to reduce the required luminous intensity. In addition, road delineators should be arranged at short intervals. The data from this study can be used to design and evaluate improved devices of road delineators on highways during snowstorms.
Measuring Efficiency of Winter Maintenance Practices
Authors: Decker Rand , Bignell John L. , Lambertsen Cambria M. , Porter Kristie L.
Published: April 2007

The need to objectively evaluate the effect of new technology and the advent of externally contracted winter maintenance have increased the need for quantitative measures of winter maintenance efficiency and effectiveness. Varying severity of winter storms and lane kilometers within a maintenance facility’s service area together largely account for storm-to-storm differences in the cost of fighting snow. Efforts were made to develop a measure of winter maintenance efficiency that accounts for labor, equipment, and material costs, as well as storm severity and duration, for an established number of lane kilometers of given service levels. The expenditures are normalized by the lane kilometers in the maintenance facility’s service area and a storm severity index. The storm severity index (WI) is a modified winter index calculated from weighted daily snowfall totals and minimum and maximum temperatures. The resulting winter maintenance metric (daily snow-fighting $/WI × lane-km) is a normalized measure of a maintenance facility’s efficiency in performing snow- and ice-control operations. Databases and resulting winter maintenance efficiency metrics were developed for the winters 1996–1997, 1997–1998, and 1999–2000 for three Utah Department of Transportation maintenance facilities. The efficiency of these three sheds is compared for the winter of 1996–1997, and the winter maintenance efficiency is considered at one shed for specific storms during winter 1998–1999. The winter maintenance efficiency metric allows maintenance managers to objectively consider storm-to-storm efficiency within a facility and to compare the storm-to-storm and annual efficiency of facilities. The impact of new technology on winter maintenance and the efficiency with which contract organizations perform snow-fighting duties can be measured with a winter maintenance metric.
Economic Evaluation of Snow-Removal Level by Contingent Valuation Method
Authors: Hayashiyama Yasuhisa , Tanabe Shintaro , Hara Fumihiro
Published: April 2007

The road management department of the city of Sapporo has improved the service level of winter road management year by year, and its current annual budget is $100 million. In the cost-benefit evaluation of winter road management, conventional studies have not included as evaluation subjects the indirect benefits, such as improvement in quality of life (an increase in pedestrian accessibility, safety, and walkability), other than benefits for traffic markets. The contingent valuation method (CVM) was adopted to include the indirect benefits in the evaluation. The results of the cost-benefit evaluation by applying CVM are described, and facts that should be taken into consideration in CVM application are discussed. Benefits of the development of winter road management levels were estimated by multiplying willingness to pay (WTP) and willingness to accept compensation (WTA) by the number of households in Sapporo (752,267 in February 1998). In the case of deteriorated winter road management level, WTP was $27 million to $33 million, and WTA was $190 million to $300 million. In the case of improved level, WTP was $17 million to $23 million, and WTA was $180 million to $200 million. The estimation results varied greatly depending on means of payment to the questioned value. This indicated that a careful examination of the suitability of the questioning method, whether WTA or WTP, is required.
Compatibility and Constraints Between High-Speed Passenger Trains and Traditional Freight Trains
Authors: Lopez-Pita Andres , Robusté Francesc
Published: April 2007

The effect of operation of mixed traffic, that is, specialized passenger transportation trains and conventional freight trains, on high-speed lines on the cost of maintaining the tracks of these lines is considered. In parallel, certain recommendations with regard to the characteristics (gradient and length) that the inclines of these lines should have so that the speeds of the freight trains are not significantly reduced are made. This phenomenon could have a negative effect on the capacity of the line and on its deterioration because of excess superelevation and the geometry of the track.
Risk and Train Control: A Framework for Analysis
Authors: Martland Carl D. , Zhu Ying , Lahrech Youssef , Sussman Joseph M.
Published: April 2007

The effects of train control strategies on the risks of railroad operations are examined. Analysis of a hypothetical 1800-km (1, 200-mi) corridor identified the main factors that increase risks. Passenger traffic is the most important factor because the addition of passenger trains creates the possibility of catastrophic accidents with dozens of fatalities. Increasing the number of trains per day leads to more than proportional increases in the risks of collisions. Single-track operations are much more susceptible to collisions, whereas higher train speeds increase both the likelihood and the severity of the consequences of accidents if there is a signal overrun or a failure to obey a slow order. Positive train control (PTC) systems can reduce most, but not all, of the collisions and overspeed derailments, as improper train handling or equipment failure could still lead to accidents. Establishment of a digital communications link to the train should also allow the possibility for improved grade-crossing protection. For the hypothetical corridor, the potential benefits from improved grade-crossing protection were on the same order of magnitude as the predicted benefits from PTC systems. If new technologies are developed to detect broken rails, the digital communications link could also be used to implement immediate braking, thereby preventing some additional derailments. The risk-based approach demonstrated may provide a more complete assessment of rail risks than a methodology that estimates safety benefits based on documentation of accidents that might have been prevented if more advanced train control techniques had been in place. Risks include the possibility of catastrophic accidents, whether or not such accidents occurred recently. A causality-based methodology also allows greater flexibility in sensitivity analysis and in assessment of trends in traffic volume, traffic mix, and other factors.
Fundamental Nonlinear Track Load-Deflection Behavior for Condition Evaluation
Authors: Sussman T. R. , Ebersöhn W. , Selig E. T.
Published: April 2007

Locations of rapid track condition deterioration are typically well known to railway track engineers, although the cause and methods of improvement may be unclear. The rapid deterioration of these locations can be due to many factors such as poor conditions of the components (rail, tie, and ballast) or failure of any of the components or subgrade. The exact cause of the problem is generally unknown as attempts to maintain the track in acceptable condition (by surfacing or undercutting) are implemented. In conjunction with track geometry measurements, which help to identify poorly performing track locations, track load-deflection behavior can contribute to the knowledge of the cause of the problem, with an ultimate goal being identification of a cost-effective, long-term solution to improving the performance of the track. Fundamentals of track load-deflection behavior, how track behavior relates to performance, indices that can be used to determine suitable maintenance strategies, and the relation of these indices to actual track performance all contribute to the evaluation. As indications of the track load-deflection behavior, several track stiffness measurement techniques that have been proposed and tested are described. The goal is to clarify the need to measure track stiffness and to identify rational means of relating the data to track condition and, ultimately, to ensure maintenance, renewal, and safety.
Track Degradation Assessment Using Gage Restraint Measurements
Authors: Alfelor Roemer M. , Carr Gary A. , Fateh Mahmood
Published: April 2007

Gage restraint is an important indicator of track condition and safety. In 1999, approximately 13 percent of derailments were caused by reductions in gage restraint and the resulting widening of the track gage. Existing techniques for the measurement of gage restraint allow identification of track sections with weak lateral support. However, little has been done to investigate the change in, or weakening of, gage restraint over time as a function of track, traffic, and environmental parameters. A track degradation assessment study is under way to develop models that can be used to predict changes in gage restraint by using data obtained from the automated Gage Restraint Measurement System. The degradation models will be useful for forecasting the future condition of the track, determining the appropriate frequency and timing of track inspections, and evaluating the effectiveness of maintenance strategies. A literature review of track degradation models and previous work on gage restraint analysis is presented. The rationale for adoption of an empirical approach to gage restraint degradation modeling is explained. The processing applied to the automatically collected data and the preliminary database program developed to store the information and estimate track degradation equations are also described. The track degradation analysis and database development study currently focuses on gage restraints and track geometry parameters as measures of condition. In the future, this can be extended to include other degradation parameters for a comprehensive track performance analysis.
Evaluation of Uniaxial Strain Transducer for Railroad Infrastructure
Authors: Yun Hae-Bum , Lee Hosin , Maclean Brian
Published: April 2007

The uniaxial strain transducer (UAST) is a microelectromechanical system that features a high resolution, a high sampling rate, and absolute encoding. It needs no calibration and has no strain drift over time. Strains measured with a UAST were compared with those measured with a typical electrical resistance strain gauge. Some discrepancies between the two sets of measurements were observed in a bending test; however, there was a good correlation between the two measurements in tension and compression tests. Strains measured with the UAST under a cyclic load followed closely the haversine loading curves generated with a Materials Testing System testing machine. To obtain reasonably accurate strain measurements under moving trainloads, a 12-bit operational mode for the UAST with a resolution of 2.81 μ∈ at 64 Hz for a loading cycle is recommended. This research project seeks to evaluate the potential for the development of a prototype hybrid UAST, which would incorporate strain data reduction algorithms into a UAST for railroad application by using existing UAST technologies.
Environmental Impact of Construction and Repair Materials on Surface Water and Groundwater: Detailed Evaluation of Waste-Amended Highway Materials
Authors: Thayumanavan Pugazhendhi , Nelson Peter O. , Azizian Mohammad , Williamson Kenneth J. , Lundy James R.
Published: April 2007

An evaluation methodology was developed to help transportation agencies make prudent decisions about the reuse of waste materials and by-products in highway construction. The primary objective of this evaluation process was to assess the potential impact on surface water and groundwater of constituents released from these materials. Test materials included coal fly ash, bottom ash, blast furnace slags, scrap tires, foundry sand, and recycled asphalt pavement. Test materials were screened for potential aquatic impact in their raw form. Then they were amended with either asphalt or aggregate for detailed assessment, including leaching (batch and flat plate or column tests) and environmental removal, reduction, and retardation (soil sorption, volatilization, photolysis, and biodegradation) tests. Short-term bioassays were used to measure directly the potential aquatic impact of derived leachates as a supplement to chemical analyses. For most materials, amendment with asphalt or aggregate largely reduced or eliminated any impact on the aquatic organisms. Among environmental factors, soil sorption appeared to be the most effective contaminant-removal mechanism. All waste-amended asphalts and aggregates exhibited no measurable impact on target organisms after soil sorption. However, for materials such as pressure-treated wood and deck sealer (used as is), environmental tests showed little or no effect in reducing their aquatic impact.
Characteristics of Storm-Water Runoff from Highway Construction Sites in California
Authors: Kayhanian Masoud , Murphy Kevin , Regenmorter Louis , Haller Richard
Published: April 2007

Fifteen highway construction sites were monitored by the California Department of Transportation (Caltrans) to assess the water quality of storm-water runoff from the sites. Caltrans conducted a study to generate sufficient water quality data to further develop management strategies and evaluate existing best management practices. A wide range of construction sites was selected for monitoring throughout the state. Both flow-paced composite and single-grab samples were collected and analyzed at these sites for a total of 72 station–storm events during the 1998–1999 and 1999–2000 wet seasons. Results obtained during the 2-year characterization study indicate the following: ( a) Caltrans construction-site runoff constituent concentrations detected during this study are less than typical Caltrans and non-Caltrans highway runoff constituent concentrations, with the exception of total chromium, total nickel, total phosphorus, total suspended solids (TSS), and turbidity. ( b) The concentrations of TSS and turbidity likely are due to the disturbed soils present at most construction sites. ( c) The origin of the high concentrations of total chromium, total nickel, and total phosphorus concentrations is unknown. Concentrations of these constituents varied between sites, so it is possible that site-specific soils and vegetative conditions contributed to the concentrations of these constituents. ( d) A correlation ( R2 values greater than 0.5) was observed between TSS runoff concentrations and particulate runoff concentrations of chromium, copper, and zinc, indicating that minimizing particulate matter may reduce total metals concentrations.
Estimation and Internet-Based Dissemination of Extreme Rainfall Information
Authors: Durrans S. , Brown Pauline A.
Published: April 2007

Information on extreme rainfall is employed extensively in design and analysis of storm-water conveyance systems and for other types of engineered hydraulic structures. Information needed for preparation of intensity-duration-frequency (IDF) curves or design storm hyetographs can be found in publications of the National Weather Service, including Technical Paper 40, HYDRO-35, and the National Oceanic and Atmospheric Administration’s Atlas 2. Rainfall data collected since the dates of these publications, and developments of improved statistical methods, have motivated several states and regions in the United States to initiate update studies. One of the new studies, for the state of Alabama, is reported. Results of the Alabama study are disseminated via an Internetbased graphical user interface, which permits users to interactively point and click on a geographical location of interest and have IDF curves or storm hyetographs returned on demand. User reactions to an Internetbased rainfall atlas have been promising and have led to additional work for the National Weather Service.
Consideration of Stream Morphology in Culvert and Bridge Design
Authors: Kosicki Andrzej J. , Davis Stanley R.
Published: April 2007

In 1992, the Maryland State Highway Administration (SHA) initiated new design procedures to limit the impact of constructing culverts and bridges in streams. Elements of the new procedures included studies to define the characteristics of Maryland streams regarding bankfull widths, depths, and discharges; training of engineers in basic and advanced courses in stream morphology presented by David Rosgen; and updating the SHA culvert design manual to address consideration of stream morphology, fish passage, and other environmental features. The revised design procedure emphasizes the need to identify all appropriate objectives at the start of the design process so the best overall solution can be determined. The design concept is to construct a stream system that is stable and that neither scours nor aggrades. Elements of this approach include maintaining the consistency of dimension, pattern, and profile of the stream with particular attention given to maintaining bankfull width and width/depth ratio. Flood plain culverts are provided where appropriate to relieve the hydraulic load on the main channel culvert to limit downstream scour and erosion. Several culverts recently were constructed by using the stream morphology concepts discussed. These initial efforts have been quite successful and indicate that it is practical to consider stream morphology concepts in culvert design.
Unreported Collisions with Post-and-Beam Guardrails in Connecticut, Iowa, and North Carolina
Authors: Ray Malcolm H. , Weir Jennifer A.
Published: April 2007

Presented are the results of an in-service performance evaluation of four guardrail systems: the G1 cable guardrail, the G2 weak-post W-beam guardrail, and the G4(1S) and G4(1W) strong-post W-beam guardrails. The study was focused particularly on estimating the number of unreported collisions and the true distribution of vehicle occupant injuries. The data were collected in portions of Connecticut, Iowa, and North Carolina during a 24-month data collection effort from 1997 to 1999. The collision performance was measured in terms of collision characteristics, occupant injury, and barrier damage. Unreported collisions were counted in all three areas by periodically inspecting guardrails in a specific control section. Because this type of data collection is both time-consuming and sensitive to methodology and human error, its use is not recommended for future in-service evaluation studies. Instead, the use of rates of injury-producing collisions per million vehicle kilometers traveled past the guardrail or other hardware, which can be determined from data on reported injury collisions, hardware inventory, and traffic volumes, is recommended.
Performance of W-Beam Splices
Authors: Ray Malcolm H. , Plaxico Chuck A. , Engstrand Klas
Published: April 2007

Structural failure of post-and-beam W-beam guardrails during impact sometimes is due to the rupture of the W-beam rail where two sections are spliced together with bolts. Summarized is a study of the mechanics of failure of the splice connection. The causes of rupture are identified, and a design alternative is formulated that will reduce the likelihood of rupture of the splice connection. The tensile forces in the W-beam rail and the mode of deformation of the splice connection during impact were critical factors considered in the study. The results of full-scale crash tests, laboratory tests, and finite element analysis indicate that relocating splices to midspan locations would greatly reduce the chance of observing a rupture of the guardrail in full-scale crash tests and in real-world collisions.
Development of Two Test Level 2 Bridge Railings and Transitions for Use on Transverse Glue-Laminated Deck Bridges
Authors: Faller Ronald K. , Rosson Barry T. , Ritter Michael A. , Keller Eric A. , Duwadi Sheila R.
Published: April 2007

The Midwest Roadside Safety Facility, in cooperation with the United States Department of Agriculture Forest Service Forest Products Laboratory and FHWA, designed two bridge railing and approach guardrail transition systems for use on transverse glue-laminated timber deck bridges. The bridge railing and transition systems were developed and crash tested for use on medium-service roadways and evaluated according to the Test Level 2 safety performance criteria provided in NCHRP Report 350. The first railing system was constructed by using steel hardware, whereas the second railing system was built by using glulam timber components. Four full-scale crash tests were performed, and the bridge railing and transition systems were determined to be acceptable according to the current safety standards in NCHRP Report 350.
Lessons from Airport Privatization, Commercialization, and Regulation in the United Kingdom
Authors: Humphreys Ian , Francis Graham , Fry Jackie
Published: April 2007

The possible lessons of airport privatization, commercialization, and regulation in the United Kingdom (U.K.) are discussed. This is both timely and topical because of the huge financial pressures on governments to meet the infrastructure investments required to accommodate the forecasts of growth in air traffic and modernization such as new, larger aircraft. In response to these trends, the U.S. government and governments around the world have looked at the U.K. as a model of privatization. It was the first nation to privatize its airports, and a variety of ownership structures have been adopted. The history of privatization, commercialization, and regulation in the U.K. is traced, and important lessons are highlighted. Regulation may be the only policy lever available to shape a privatized and commercialized airport system and its role within a wider integrated transport strategy. The authors contend that a commercialized model of ownership similar to that at many U.K. municipal airports could be adopted in the United States, potentially relieving the financial pressure on the federal government to fund development. Countries need to have a strategic airports policy to guide development toward national, economic, and environmental goals.
Evaluating Cost-Effectiveness of an Air Traffic Management System for Europe: Development and Application of Methodological Framework
Authors: Zografos Konstantinos G. , Giannouli loanna M.
Published: April 2007

In response to growing air transport congestion, new air traffic management (ATM) concepts have been put forward to ameliorate existing problems. By their nature, ATM systems are highly complex, and their development and implementation require substantial financial resources. Moreover, the introduction of a new ATM system generates tangible as well as intangible benefits and costs. Therefore, a methodological framework capable of addressing all specific characteristics of the ATM system cost-effectiveness evaluation should be developed. The objective of this paper is twofold: first, to develop a methodological framework for evaluating the TORCH system (i.e., a new ATM concept for Europe), and second, to present the results of the application of the proposed framework for assessing the cost-effectiveness of the TORCH system. The proposed methodology was applied with the help of a panel of European ATM experts. The application results are intuitively appealing and indicate a strong convergence of the expert opinions concerning the most preferable ATM system. More specifically, the results of the evaluation suggest that an investment in TORCH will improve the safety, operational, and environmental performance of the ATM system as well as the working conditions of the air traffic controllers, and at the same time, the TORCH system will be marginally cost-effective.
Investigation of Information Needs of Departing Air Passengers
Authors: Burdette Debra , Hickman Mark
Published: April 2007

Specific information needs of departing air travelers for pretrip and enroute phases of trips to the airport were studied and identified. From the results, effective plans for providing supplementary information in support of groundside travel information can be developed by local, state, and national agencies. To better understand air passenger information needs, personal interviews were conducted with 216 passengers at George Bush Intercontinental Airport in Houston, Texas. One major finding from this research was that, in general, passengers are content with the types of real-time travel information that are presently available. Specifically, survey results showed that passengers currently use and prefer access to flight information including confirmed schedules, flight delays, and gate assignments. Also, most passengers prefer to receive travel information earlier in their trip (i.e., before beginning their trip), thus validating theories that suggest that if passengers are to effectively evaluate transportation options, they must have information earlier in the decision-making process. Lastly, based on the survey results, air passengers indicated they prefer to use airline employees, e-mail, telephones, and the Internet when making future travel information inquiries. In particular, business travelers were found to have a higher affinity toward e-mail and pagers, whereas younger travelers simply preferred newer technologies to receive travel information. As a result, these population categories are prime targets for information services marketing. Overall, each of these findings was similar to—and confirmed the results from—previous studies.
Sequential Warning-Light System for Work-Zone Lane Closures
Authors: Finley Melisa D. , Ullman Gerald L. , Dudek Conrad L.
Published: April 2007

Research performed to assess the effectiveness of a flashing warning-light system for use at work-zone lane closures is summarized. The system is composed of a series of interconnected, synchronized flashing warning lights that produce the illusion of motion. Researchers investigated motorist understanding and perceived usefulness of various designs of the warning-light system, and the potential of this system to yield significant operational or safety benefits in actual work-zone applications. Results from proving ground and field studies show that the flashing warning-light system used in the work-zone lane closure is perceived positively and is not confusing to the motoring public. The field-study results also revealed that the prototype warning-light system may encourage motorists to vacate a closed travel lane farther upstream from the work zone (which is believed to offer a potential safety benefit). When the warning-light system was activated at the urban freeway test site, a relatively new closure, there was a one-fourth reduction in the number of passenger vehicles and a two-thirds reduction in the number of trucks in the closed lane 305 m (1,000 ft) upstream of the lane closure. However, the system did not significantly affect lane choice at the rural road test site where the lane closure had been installed for 6 months. Thus, the greatest potential safety benefit of the warning-light system may be when it is used in conjunction with short-duration or intermediate-term maintenance or construction projects.
Delivering Road Weather Information to the Traveling Public
Authors: Hansen Blake G. , Martin Peter T. , Perrin H. Joseph , Meldrum David
Published: April 2007

Data obtained from road weather information system (RWIS) technology have been successfully applied to road maintenance and to a lesser extent traveler information. Before the information is disseminated publicly, several questions must be asked. For instance, what RWIS information does the public want and how do they want to receive it? Insight into the answers to such questions was provided by a study that involved a series of questionnaires provided to four potential user groups of RWIS information: commuters, recreational travelers, long-distance travelers, and truckers (including dispatchers). The results show that variable message signs, commercial radio, and highway advisory radio are the most popular forms of delivery methods. No strong preference was identified for telephone services, paging services, or in-car navigation systems. Road condition information is preferred by all groups over information on alternate routes, travel times, or travel speeds. The surveys indicate that road conditions that inhibit vehicle performance, such as accumulating snow, fog, ice, wind, and road closures, are most important to users. Information about rain, nonsticking snow, thunderstorms, and snow flurries is less important to users. Users prefer delivery time from 1 h before departure and while en route.
Factors Inducing Multivehicular Collisions During Visibility Reduced by Snowstorm
Authors: Kajiya Yasuhiko , Kaneda Yasuhiro , Tanji Kazuhiro
Published: April 2007

Many factors are thought to relate to the occurrence of multivehicular collisions during snowstorm. These factors were analyzed by using a database and observations of multivehicular collisions. In addition to severe road weather conditions and surrounding environment during snowstorm, the drivers’ driving attributes and the traffic factors also were found to relate closely to such accidents. From these results the risk factor level was examined to assess the occurrence risk of multivehicular collision. When these risk factor levels were applied to collision cases, they closely expressed the occurrence risk. Although many challenges remain in developing a quantitative evaluation method of risk assessment, the factors identified in this study enable objective assessment of the risk of multivehicular collisions during snowstorm by consideration of the road weather, environmental, and traffic conditions of the site.