bluuebunny/crossref_metadata_2025 huggingface dataset:
Intramural Vascular Edema in the Brain of Goats With Clostridium perfringens Type D Enterotoxemia
Authors: Ortega Joaquín , Verdes José Manuel , Morrell Eleonora L. , Finnie John W. , Manavis Jim , Uzal Francisco A.
Published: January 2019

Enterotoxemia caused by Clostridium perfringens type D is an important disease of sheep and goats with a worldwide distribution. Cerebral microangiopathy is considered pathognomonic for ovine enterotoxemia and is seen in most cases of the disorder in sheep. However, these lesions are poorly described in goats. In this article, we describe the vasculocentric brain lesions in 44 cases of caprine spontaneous C. perfringens type D enterotoxemia. Only 1 goat had gross changes in the brain, which consisted of mild cerebellar coning. However, 8 of 44 (18%) cases showed microscopic brain lesions, characterized by intramural vascular proteinaceous edema, a novel and diagnostically significant finding. The precise location of the edema was better observed with periodic acid–Schiff, Gomori’s, and albumin stains. Glial fibrillary acidic protein and aquaporin 4 immunostaining revealed strong immunolabeling of astrocyte foot processes surrounding microvessels. The areas of the brain most frequently affected were the cerebral cortex, corpus striatum (basal ganglia), and cerebellar peduncles, and both arterioles and venules were involved. Most of the goats of this study showed lesions in the intestine (enteritis, colitis, and typhlitis), although pulmonary congestion and edema, hydrothorax, hydropericardium, and ascites were also described. Although the intramural edema described, for the first time, in these caprine cases is useful for the diagnosis of enterotoxemia when observed, its absence cannot exclude the disease.
Inter- and Intraobserver Agreement of Canine and Feline Nervous System Tumors
Authors: Belluco Sara , Avallone Giancarlo , Di Palma Stefano , Rasotto Roberta , Oevermann Anna
Published: January 2019

In routine diagnostic activity, pathologists may be confronted with nervous system tumors. The lack of clinical information, economic restrictions for additional testing, and the lack of expertise in neuropathology may render the diagnosis challenging. The goals of this study were to assess the agreement in diagnosing nervous system tumors in domestic carnivores among 4 board-certified surgical pathologists without particular expertise in neuropathology and a neuropathologist expert, and to investigate the utility of special stains frequently used in routine diagnostic laboratories. Forty-six tumors (7 cats, 38 dogs, and 1 unknown carnivore) were retrieved and 1 hematoxylin and eosin–stained slide per tumor was selected. Diagnoses (tumor type and subtype) were formulated based on histological features and available clinical information. Confidence in the diagnosis was also scored. Subsequently, a panel of histochemical and immunohistochemical stains (Gordon Sweet silver stain and immunohistochemistry for AE1/AE3, vimentin, glial fibrillary acid protein, S100, neuron-specific enolase and neurofilament) was evaluated by the pathologists, who either confirmed or changed their original diagnoses. Intraobserver and interobserver agreement and confidence in relation to diagnosis before and after analysis of special stains were assessed. The use of special stains increased the complete agreement among surgical pathologists, with regard to tumor type, from 63% to 74%. Cases with a high confidence score had a higher interobserver agreement than cases with a low confidence score. These results suggest that pathologists without expertise in neuropathology agree in the diagnosis of most nervous system tumors, and special stains available in most laboratories only slightly increase this agreement.
Post Hoc Quantile Test for One-Way Analysis of Variance Using a Double Bootstrap Method
Authors: Spiegelman Cliff , Gates Tim J.
Published: January 2019

Comparing samples from two or more populations is among the most common statistical tasks that engineers and scientists perform. Typically a t-test or one-way or two-way analysis of variance is used to compare the means of different populations. Although these tests are useful for describing differences in means for various populations, they are of limited use for comparison of other population parameters, such as quantiles (i.e., percentiles). Quantile comparisons are useful for examining the changes that occur to portions of the population away from the median. Comparison of speed percentiles is especially important to the traffic engineering profession to determine the effect of various treatments on speeds of faster drivers (e.g., 85th percentile speeds). Simply testing the mean speed values does not indicate whether the differences occur because of slower traffic driving more slowly, faster traffic driving more slowly, or both. Furthermore, are positive effects on faster drivers being masked by contrasting effects on slower drivers? The main obstacle to providing confidence intervals and tests for quantiles is calculating reasonable estimates of variances for the sample quantiles that are far from the median. This paper describes a nonparametric double bootstrapping procedure for direct comparison of quantiles of two or more sample populations. The first bootstrap simulation is used to produce estimates of standard errors for the desired quantiles and thereby overcome the inability to make reasonable variance estimations. The second layer of bootstrap simulations is used to determine the threshold cutoff values based on a desired level of confidence for the test of hypothesis. The cutoff values also may be used to form confidence intervals. The steps of the procedure along with an example of its use are provided.
Analysis of Red Light Running Crashes Based on Quasi-Induced Exposure and Multiple Logistic Regression Method
Authors: Yan Xuedong , Radwan Essam , Birriel Elizabeth
Published: January 2019

According to recent national statistics, red light running crashes represent a significant safety problem at signalized intersections. To examine the overall characteristics of red light running crashes, this study used the 1999 to 2001 Florida crash database to investigate the crash propensity related to traffic environments, driver characteristics, and vehicle types. The quasi-induced exposure concept and multiple logistic regression technique were used to perform this analysis. The results showed that traffic factors including number of lanes, crash time, weather, highway character, day of week, urban or rural location, speed limit, driver age, alcohol or drug use, physical defect, driver residence, and vehicle type were significantly associated with the risk of red light running crashes. Furthermore, it confirmed that there were significant interaction effects between the risk factors, including crash time and highway character, number of lanes and urban or rural location, weather condition and driver age, driver age and gender, alcohol or drug use and gender, and type of vehicle and gender.
Role of Exposure in Analysis of Road Accidents
Authors: Van den Bossche Filip , Wets Geert , Brijs Tom
Published: January 2019

Exposure is a key variable in traffic safety research. In the literature, it is noted as the first and primary determinant of traffic safety. In many cases, however, no valid exposure measure is available. In Belgium, monthly traffic counts for 12 years are available. This offers the opportunity to investigate the added value of exposure in models, next to legal, economic, and climatologic variables. Multiple regression with autoregressive moving average (ARMA) errors is used to quantify the impact of these factors on aggregated traffic safety. For each dependent variable, a model with and without exposure is constructed. The models show that exposure is significantly related to the number of accidents with persons killed and seriously injured and to the corresponding victims, but not to the lightly injured outcomes. Moreover, the addition or deletion of exposure does not influence the effects of the remaining variables in the model. The effects of exposure clearly depend on the type of measure used and on the time horizon considered. The framework of a regression model with ARMA errors allows for missing variables being accounted for by the error term. Even without a variable such as exposure, valid models can be constructed.
Evaluation of Safety Benefits and Potential Crash Migration Due to Shoulder Rumble Strip Installation on Connecticut Freeways
Authors: Smith Erika B. , Ivan John N.
Published: January 2019

With the encouragement of FHWA, many states are installing shoulder rumble strips to reduce the number of run-off-the-road crashes. In 1996, Connecticut began full-scale installation of shoulder rumble strips on limited-access highways (freeways). This paper describes research aimed at answering three questions about the effectiveness of this project: (a) Do rumble strips reduce single-vehicle, fixed-object crashes? The analysis indicates that installing shoulder rumble strips reduces these crashes by 33%. (b) Do certain roadway factors influence the rate of these crashes with regard to the rumble strip installation locations? In the sections where rumble strips were installed, run-off-the-road crashes were reduced by as much as 48.5% in interchange areas and as little as 12.8% on sections of roadways where the speed limit was less than 65 mph. (c) Is the potential adverse effect of crash migration (from locations with rumble strips to those without) occurring? The roadway factors analyzed and sections of longer routes in Connecticut both indicate increases in run-off-the-road crashes where rumble strips are not placed, even when exposure is controlled. These findings indicate that for rumble strips to be most effective along freeways, consideration should be made for continuous installation both to reduce crashes where they are installed and to avoid increases in crash occurrence where they are not.
Investigation of Median Trees and Collisions on Urban and Suburban Conventional Highways in California
Authors: Sullivan Edward C. , Daly James C.
Published: January 2019

This study examines safety in the presence of large trees in curbed medians of conventional highways that are also principal streets in developed urban and suburban areas. Statistical modeling methods were used to associate collision frequency and severity with highway and traffic characteristics, with and without median trees. The methods include simple accident rates and three types of multivariate modeling and use collision data for 6 years. The analysis was done in two parts. The first part was a screening investigation of pertinent facilities under both state and local jurisdiction. The second part, described here in detail, focused on 14,283 collisions occurring on 58 mi (99 km) of designated state highways in 29 different sections, 19 with median trees. The analysis examined different subsets of reported collisions, in turn omitting collisions on the right side of the road, collisions not having median or median-shoulder involvement, and collisions at intersections. The overall conclusion is that large trees in medians of major conventional urban and suburban highways of state jurisdiction are associated with more collisions and increased severity. However, some of these associations are statistically weak. For the situations examined, lower speeds and larger side clearances were not found to mitigate the increased collision impacts associated with median trees.
Collision Frequency Analysis Using Tree-Based Stratification
Authors: Park Young-Jin , Saccomanno Frank F.
Published: January 2019

Although several factors are known to contribute to collisions at highway–railway grade crossings, the mixed effects of the control factors such as a highway class and other countermeasures on collision occurrence are less well explored. This study evaluates the relationship between countermeasures and collision occurrence by using a sequential analytic strategy that combines the tree-based data stratification method with the generalized linear regression technique. After the control factor effects were controlled with the use of the tree-based data partitioning method, stratified collision prediction models were developed, and the adjusted effect of the selected countermeasures was identified. The conventional statistical models were also provided for comparison with stratified models. The study used Canadian inventory and collision data to demonstrate the expected collision reductions resulting from changes in selected countermeasures, such as warning devices and posted speed limit.
Safety Impacts at Intersections on Curved Segments
Authors: Savolainen Peter T. , Tarko Andrew P.
Published: January 2019

Indiana geometric design policy, consistent with national standards, allows for the design of intersections on superelevated curves if other solutions are prohibitively expensive. Consequently, the Indiana Department of Transportation (DOT) has built a number of such intersections. Following a series of fatal crashes at one of these intersections, Indiana DOT made a decision to avoid designing intersections on segments with steep superelevation. This design restriction calls for expensive alternatives, such as realigning roads or adding grade separations. This research was done to determine whether superelevated intersections were more hazardous than similar intersections located on tangents and, if so, to determine what combination of factors made this true. The research focused on two-way stop-controlled intersections where the mainline was a high-speed four-lane divided highway located on a superelevated curve. An attempt was made to analyze as many factors as possible by using appropriate comparison techniques. Negative binomial models were developed to determine the statistical relationship between crash occurrence and intersection geometric characteristics, including curvature of the main road. Crash severity and the joint impact of curvature with weather and lighting conditions were examined by using binomial comparisons of proportions. Research findings show significant increases in crash frequency and severity at intersections located on superelevated curves.
Safety Effects of Speed Limit Changes
Authors: Kweon Young-Jun , Kockelman Kara M.
Published: January 2019

This work estimates the total safety effects of speed limit changes on highspeed roadways by using traffic detector data and Highway Safety Information System data from 1993 to 1996. To gauge the total effects, the study applies a sequential modeling approach: average speed and speed variance models are first estimated on the basis of roadway design, use, and speed limit information. Then, crash counts (of varying severity) are estimated on the basis of the speed estimates, design, and use variables. The 4 years of data come from 63,937 homogeneous roadway segments along seven Interstates and 143 state highways in Washington State. A random effects negative binomial model was selected among several alternative panel and nonpanel models for count data. Results indicate that the average road segment in the data set can be expected to exhibit lower nonfatal crash rates up to a 55 mph (88 km/h) speed limit. In contrast, fatality rates appear unresponsive to speed limit changes. Fatal and nonfatal rates fall for design reasons, including wider shoulders and more gradual curves, which appear to be key design variables. However, fatal and nonfatal rates move differently when traffic levels rise, with nonfatal rates remaining unchanged and fatal rates falling.
Safety Performance Functions for Signalized Intersections in Large Urban Areas
Authors: Lyon Craig , Haq Anwar , Persaud Bhagwant , Kodama Steven T.
Published: January 2019

This paper describes the development of safety performance functions (SPFs) for 1,950 urban signalized intersections on the basis of 5 years of collision data in Toronto, Ontario, Canada. Because Toronto has one of the largest known, readily accessible, urban signalized intersection databases, it was possible to develop reliable, widely applicable SPFs for different intersection classifications, collision severities, and impact types. Such a comprehensive set of SPFs is not available for urban signalized intersections from data for a single jurisdiction, despite the considerable recent interest in use of these functions for analyses related to network screening, and the development, prioritization, and evaluation of treatments. The application of a straightforward recalibration process requiring relatively little data means that the SPFs calibrated can be used by researchers and practitioners for other jurisdictions for which these functions do not exist and are unlikely to exist for some time. The value of the functions is illustrated in an application to evaluate a topical safety measure—left-turn priority treatment for which existing knowledge is on a shaky foundation. The results of this empirical Bayes evaluation show that this treatment is quite effective for reducing collisions, particularly those involving left-turn side impacts.
Vehicle Occupancy and Crash Risk
Authors: Geyer Judy A. , Ragland David R.
Published: January 2019

This study explores the association between vehicle occupancy and a driver's risk of causing a fatal crash, not wearing a seat belt, and using alcohol. The survey population is the set of drivers represented in the Fatal Analysis Reporting System for 1992 to 2002. The independent variables are driver age, driver gender, passenger age, passenger gender, and vehicle occupancy. The outcome variables are whether the driver was at fault in causing the fatal crash, whether the driver wore a seat belt, and whether the driver had used alcohol. For male teenage drivers, driving with teenage passengers correlated with an increased risk of causing a crash. For all female drivers and for male drivers over age 40, passenger presence correlated with a reduced risk of causing a fatal crash. Drivers ages 15 to 30 were less likely to wear a seat belt when passengers were present than when driving solo. Drivers age 50 and older had higher rates of seat belt use when passengers were present. This protective effect of passengers was stronger for male drivers than female drivers, and for male drivers the effect increased by age. Drivers ages 15 to 34 accompanied by passengers were more likely to have consumed alcohol than solo drivers of the same age group. These results offer an interesting perspective for research in the area of driver distraction, and they update current knowledge on older drivers and the role of seat belt and alcohol awareness.
Use of Heteroscedastic Ordered Logit Model to Study Severity of Occupant Injury
Authors: Wang Xiaokun , Kockelman Kara M.
Published: January 2019

A heteroscedastic ordered logit model was used to study the effects of various vehicle, environmental, roadway, and occupant characteristics on the severity of injuries sustained by vehicle occupants, conditional on the crash occurrence. As expected, the models found that heavier vehicles increased both a vehicle's crashworthiness and driver aggressiveness toward others. The models also found that if all passenger vehicles were to become 1,000 lb heavier, crash injury outcomes would not change dramatically. However, if all passenger cars were to become light-duty trucks (i.e., minivans, pickups, and sport utility vehicles) of the same weight, incapacitating injuries and fatalities were predicted to rise by 26% and 64%, respectively. Beyond weight and vehicle type, many other factors were controlled for as well. For example, older occupants and female occupants were more likely to experience injury and death, particularly when navigating curved roadway sections with higher speed limits.
Understanding Grain Movements for Demand Estimation
Authors: Jessup Eric , Casavant Ken
Published: January 2019

Grain producers and handlers in Washington State have benefited from a multimodal transportation network of roads, railroads, and the Columbia–Snake River barge system to move large amounts of grain effectively in a timely and economic manner. The competitive environment of the grain industry brings many changes, including the number of firms and houses, mergers, and modal competitiveness. Additionally, marketing strategies are affected because choices of available transportation modes reflect the decision processes of warehouses or firm managers. This aggregate study of grain marketing and transportation in the Pacific Northwest helps lay the groundwork for subsequent estimates of empirical demand. Such subsequent modeling attempts may include revealed and stated preference analysis in discrete choice demand models. A thorough understanding of the industry and market characteristics should improve empirical estimation efforts and produce more defensible policy analysis. Based on a 90% shipment volume response rate, results show that in the Columbia–Snake River grain situation, one destination absorbs more than 90% of shipments. Modal competition is active; barge has a market share of more than 50%, down 12–16% from 10 years ago. Multiple-car shipments have increased, but not drastically. Rates are consistently competitive over the period. Finally, grain demand is seasonal but generally has been stable over time. The revealed preferences from this aggregate analysis suggest that price elasticity may vary across shippers, times of movement, and modal availability.
Model of Spatial Market Areas and Transportation Demand
Authors: Henrickson Kevin E. , Wilson Wesley W.
Published: January 2019

A model of transportation demand and the interrelated supply decisions of agricultural shippers is derived over a geographic space. These shippers use prices to procure grain and to make output, mode, and market decisions. Each decision is affected by the characteristics of the region and the level of spatial competition between the shipper and its rivals. All of these factors are integrated into the model of derived demand and spatial competition. The model is applied to data that represent barge elevators on the upper Mississippi and Illinois Rivers to estimate transportation demands and gathering areas. The results provide demand elasticity estimates for annual volumes between −1.4 and −1.9, which are sizably larger than previous estimates of similar traffic. The results also indicate that inbound transportation rates to the barge shipper as well as distance to the nearest competitor have a significant influence on annual volumes. A second model, explaining the size of the market areas of elevators, is also estimated. The rates of alternative modes that compete for barge traffic as well as distance to the nearest competitor influence market areas. The results provide for a strong argument that transportation demands are elastic and that spatial market areas vary substantially with transportation rates.
Measuring Nontraditional Benefits and Costs of Inland Navigation
Authors: Sudar Anne
Published: January 2019

The evaluation of navigation projects has evolved from a standard procedure done strictly by engineers and economists to a process that involves a wide range of stakeholders. Not surprisingly, these diverse stakeholders have different views regarding what should count in the benefit–cost analysis of water resource development projects and how the effects are to be economically valued. The methodologies that are described have been used to measure and monetize some of the externalities of inland navigation, the benefits and costs of which have not traditionally been included in benefit–cost ratios. The emphasis is the benefits (lower air emissions) associated with freight transport via water compared with those of other modes, particularly truck.
European Transport Policy and Role of the Danube River
Authors: Pfaff Wolfgang
Published: January 2019

Europe's strategies to overcome the challenges in its transport networks since the 1990s are described. In the 1990s, emerging traffic problems and the increasing number of bottlenecks in Europe's transport infrastructure forced the European Union to take action toward integrated transport planning. The political changes in Eastern Europe in 1989 needed to be considered in the development of infrastructure planning, and in 1996 the European Union defined the trans-European network, which covers all transport modes. The transport infrastructure needs assessment process analyzed the transport infrastructure in these countries from 1997 to 1999. Two conferences in 1994 and 1997 defined 10 Pan-European transport corridors in the European Union's neighboring areas. Corridor VII represents the Danube River from Germany to its delta at the Black Sea [2,415 km (1,500 mi)]. The Danube is connected by the Main–Danube Channel with the Rhine River and thus is a backbone of inland navigation in Europe. Improvement of the Danube is one of 30 prioritized projects that were defined by the Van Miert High-Level Group in 2003. Corridor VII has a high potential to solve upcoming transport problems in southeastern Europe. However, inland navigation must improve its services to meet the logistics market's requirements; many European Union–funded and national projects foster these aims.
European Water Framework Directive and Its Impact on Water Transport in the European Union
Authors: Sturm Jürgen
Published: January 2019

As a result of the July 1999 European Summit held in Gothenburg, Sweden, all European Union policy areas are subject to the guiding principle of sustainable development. Within this context, the European Commission published a white paper on transport policy to 2010, focusing on the need to foster more environmentally and socially sustainable means of transport to achieve a modal shift away from road transport. The white paper mentions inland navigation as a mode with great potential to contribute to a shift toward more sustainable modes than roads and recognizes that among other measures, infrastructural improvements must be realized on the European waterways. However, European environmental legislation, namely, the Water Framework Directive (WFD), is likely to challenge the strategy of necessary improvements on European waterways. The target conflict arising from environmental legislation that is capable of contradicting efforts to ensure sustainability in the transport sector is examined. Within this context, several aspects of WFD are described: development; the current implementation status in the national law of European Union member states and the potential consequences for waterway infrastructure, dredging, and navigability; and the general role of inland navigation in a competitive transport market. Possible instruments foreseen in the WFD to balance the interests of environmental concerns and those of the navigation sector are also addressed.
Rural Water Transport and Development
Authors: Aka Kouadio Akou
Published: January 2019

The Grand-Lahou region, a rural environment in Ivory Coast with waterways used for fishing and navigation, is studied as part of the Waterways and Livelihoods program of the International Forum for Rural Transport and Development. Agriculture is an important activity that employs the majority of the population in the Grand-Lahou region. Water transport is vital to the region because of its isolated location and its important relationship with Abidjan, the main consumer center. The study highlights the advantages and limitations of the area. It also demonstrates the way that water transport functions, the imbalance in supply and demand for transport that gives rise to a need for additional and more suitable means of transport, and the strategies for the development of water transport that have been adopted by different actors. Water transport in the Grand-Lahou region is a tradition that should be preserved in a way that takes into account the region's evolving socioeconomic realities.
Design of Alert Criteria for an Intersection Decision Support System
Authors: Shladover Steven E. , VanderWerf Joel , Ragland David R. , Chan Ching-Yao
Published: January 2019

This paper describes the design and preliminary evaluation of the criteria for alerting drivers to a specific set of intersection hazards. The research is being conducted as part of the development of an intersection decision support (IDS) system that uses the sensing and computational technologies of infrastructure-based intelligent transportation systems. The IDS system under consideration is intended to help drivers avoid conflicts with oncoming traffic when they are making left turns under a permissive (i.e., unprotected) green signal. These conflicts account for a significant proportion of intersection crashes and are difficult to mitigate without imposing serious costs and burdens on intersection capacity associated with providing a protected left-turn signal cycle. The human factors and sensing issues that need to be considered in designing the system are discussed and are followed by a description of the logic used to define the gaps in opposing traffic that should be considered adequate for left-turn maneuvers. The simulation model used to evaluate alternative system designs is described, and sample results are shown for evaluation of the effectiveness of a warning under a relatively stressful scenario. The influence of alternative sensor configurations on the effectiveness of the warning is illustrated and indicates the importance of providing information about both the presence and speed of approaching vehicles sufficiently far from the intersection.
Dedicated Short-Range Wireless Communications for Intelligent Transportation System Applications
Authors: Liu Yu , Dion François , Biswas Subir
Published: January 2019

In efforts to reduce traffic accidents and improve the efficient utilization of existing transportation networks, increasing attention is being given to the use of wireless communications between vehicles and roadside equipment to develop new intelligent transportation system (ITS) applications that can help improve the safety of transportation networks and reduce urban congestion. Of particular interest for the development of such applications are the currently proposed dedicated short-range communication (DSRC) wireless standards. This paper aims to provide transportation researchers and engineers with an introduction to these standards. The paper presents the current mobile wireless communication applications and standards, the various DSRC standards that have been proposed, their potential use in ITS applications, their envisioned implementation benefits, and the remaining research needs.
Comparison of Mobility Impacts on Urban Commuting
Authors: Vasudevan Meenakshy , Wunderlich Karl , Larkin James , Toppen Alan
Published: January 2019

This paper explores the effectiveness of relying on commercial radio as a source of traveler information and presents an approach to quantify mobility benefits from radio traffic advisories. The study, conducted for the Washington, D.C., metropolitan area, used an analytical technique called the heuristic online web-linked arrival time estimator to examine whether broadcast traffic advisories could have mobility benefits similar to a prospective notification-based traveler information service offering personalized estimates of travel times. Traffic reports were recorded from a local radio station and manually coded to translate them into a suitable format for analysis. Results from the analysis of 37 weekdays consisting of 4,410 advisories indicated that radio traffic advisories were less effective in improving traveler on-time reliability or reducing travel disutility than a service offering route-specific travel time reports. The simulated commuter receiving regular quantitative estimates of travel times on relevant roadways typically made more effective route and trip-timing decisions than the simulated commuter receiving comparatively incomplete, irregular, and vague advisories on prevailing congestion conditions from broadcast traffic reports. In contrast, the simulated commuter listening to radio advisories recorded similar benefits to those of the simulated control subject, who ignored all forms of traveler information. During the morning peak period, the simulated radio listener fared worse than the simulated control subject and recorded lower on-time reliability performance and higher travel disutility. During the afternoon peak period, the simulated radio listener had lower travel disutility but also experienced a nominal reduction in on-time reliability performance.
Benefit and Cost Parameters of Intelligent Transportation Systems
Authors: Hadi Mohammed A. , Quigley Diane , Sinha Prasoon , Hsia Liang
Published: January 2019

The Intelligent Transportation Systems (ITS) Deployment Analysis System (IDAS) is a sketch planning analysis tool that can be used to estimate the impacts and costs resulting from the deployment of ITS components. The program includes default values for the parameters required to calculate ITS deployment costs and benefits. IDAS allows users to override the default values of ITS device cost and benefit parameters, including unit cost estimates, cost assumptions, benefit module parameters, ITS impacts, and impact dollar values. On one hand, the use of cost and benefit parameter values that better represent the region under consideration is expected to produce better assessments of ITS deployment alternatives. On the other hand, collection of regional ITS cost and benefit parameters could be expensive, and some required parameters might not be available for the region under consideration. For this reason, IDAS users tend to use many of the program's default values in their analyses. This paper reports on the results of a project that was initiated by the Florida Department of Transportation to identify Florida-specific cost and benefit parameters for use as inputs to IDAS ITS alternative assessments in Florida. The paper also compares the results obtained by using these derived parameters with the results obtained by using the national defaults when a real world ITS deployment project is being evaluated. The produced cost estimate for this deployment project is also compared with the actual cost of the project.
Network and Communication Design of a Work Zone Intelligent Transportation System
Authors: Lou James Z.
Published: January 2019

Road construction on major freeways is a primary cause of traffic incidents and delays. One approach to improve traffic mobility and safety in construction work zones is to use intelligent transportation systems (ITSs), which can effectively enhance work zone traffic management through advanced surveillance and communication technologies. Although conceptually similar to a traditional advanced traffic management system, a work zone ITS has unique network and communication design requirements. The Palm Beach County, Florida, Interim Traffic Management System (ITMS) was a work zone ITS that was successfully deployed in the summer of 2003. Using Palm Beach County ITMS as an example, this paper provides technical guidelines for applying cutting-edge technologies, such as wireless communication, video compression, and Internet protocol encapsulation, in designing a work zone ITS.
Approaches for Introducing Intelligent Transportation Systems into Developing Countries
Authors: Yokota Toshiyuki , Weiland Richard J. , Yamagata Hiroo
Published: January 2019

The use of intelligent transportation systems (ITSs)—the application of information and communication technology to road transportation—is emerging to address a variety transportation-related problems. While countries with developing and transitional economies can learn a lot from the ITS experiences of developed countries, they need to develop their own approaches to ITS. The reasons for this are the high speed at which ITS technology is advancing to bring better performance at lower costs and the arrival of new, innovative approaches for both the initial incentives for introducing ITS and the actual introduction process. To support these new opportunities, the World Bank developed a series of five ITS Technical Notes for countries with developing and transitional economies and appendixes that include the 130 examined cases of ITS deployment. The purpose of this paper is to introduce and provide highlights from the ITS Technical Notes. In particular, on the basis of the ITS Technical Notes, this paper (a) explains the new incentives for introducing ITS, particularly in developing countries, that focus on reliability as well as on social benefits; (b) discusses a number of innovative approaches; and (c) introduces a model to assist the selection of the proper application. The model helps decision makers to select the right applications and also informs users about the requirements of the recommended applications. The model presented here can provide useful guidance and a study tool to help users in developing countries to achieve maximum benefits from ITS.
Efficiency of Simulated Vehicle-to-Vehicle Message Propagation in Atlanta, Georgia, I-75 Corridor
Authors: Wu Hao , Lee Jaesup , Hunter Michael , Fujimoto Richard , Guensler Randall L. , Ko Joonho
Published: January 2019

Exploitation of in-vehicle information technology (e.g., mobile computing and wireless communications) in surface transportation systems is a clearly emerging trend. Equipping vehicles with computing, communication, and sensing capabilities presents significant opportunities for a vast array of transportation services. Vehicle-to-vehicle (V2V) communication may be considered for applications such as incident detection, crash reporting, traveler information dissemination, and network operations. In-vehicle computing systems facilitate the customization of information services to the needs and characteristics of individual travelers. In addition, these systems allow coverage to extend beyond areas where roadside equipment has been placed. This study provides the initial investigation needed to test the feasibility of these advanced communication networks. Several observations may be drawn from the study. First, V2V communication is a feasible way to propagate information along the I-75 freeway in the Atlanta, Georgia, area during peak or high-density traffic periods. With sufficient fleet penetration ratio and traffic density, information can quickly propagate through the system. Second, the simulation methodology described in this study allows researchers to estimate the required fleet penetration ratio for effective communication given the traffic density and application requirements. Third, delay in message propagation is highly variable until instrumented-vehicle density reaches a critical mass. For applications requiring highly reliable, minimal message propagation delay, it may be necessary to design networks that provide extra support to avoid such variation. Research is required to examine additional traffic conditions (e.g., congestion due to an incident) and study the effectiveness of this approach for particular applications.
Bosporus Bridge Toll Plaza in Istanbul, Turkey
Authors: Sahin Ismail , Akyıldız Güzin
Published: January 2019

The Bosporus Bridge in Istanbul, Turkey, is the first of the two highway crossings connecting Asia and Europe over the Bosporus Strait. Drivers must pay their toll in the Europe-to-Asia direction at a toll plaza comprising 15 lanes. Manual and electronic payment methods are available in the plaza. The analysis of data showed that several factors affect both the throughput of the plaza and the traffic flows approaching it. Among the factors were whether a particular toll lane was in service, the contraflow lane operation toward the plaza, the lane operators’ performance, and the queue lengths in the plaza area. Rescaled cumulative vehicle count curves were used as the analysis tool. This allowed observation of (a) flow changes at particular points along the section of the highway studied and (b) propagation of the kinematic waves upstream of the plaza. The observations could be used for improving the performance of the plaza and for traffic management decisions associated with the afternoon peak period.
Test Bed for Multiagent Control Systems in Road Traffic Management
Authors: van Katwijk R. T. , van Koningsbruggen P. , De Schutter B. , Hellendoorn J.
Published: January 2019

A test bed for multiagent control systems in road traffic management is presented. As the complexity of traffic control on a network grows, it becomes more difficult to coordinate the actions of the large number of heterogeneous traffic management instruments that are available in the network. One way of handling this complexity is to divide the coordination problem into smaller coherent subproblems that can be solved with a minimum of interaction. Multiagent systems can aid in the distribution of the problem (over the various agents that compose the multiagent system) and facilitate the coordination of the activities of these agents when required. In the literature, no consensus exists about the best configuration of the traffic-managing multiagent system and how the activities of the agents that compose the multiagent system should be coordinated. The decomposition of a problem into various subproblems is an active field of research in the world of distributed artificial intelligence. A survey of approaches reported in the literature is presented. Subsequently, both the test bed and the modules that compose it are introduced. Finally, an application is presented that illustrates some of the research the test bed has made possible.
Maintenance Quality Management and Environmental Stewardship
Authors: Venner Marie
Published: January 2019

Some of the most extensive information management and decision support systems at state departments of transportation (DOTs) are used in maintenance for condition tracking, work planning, budget estimation, and quality assurance. DOTs are confronted with the challenge of managing these and emerging environmental information and decision support needs in integrated systems that incorporate transportation and environmental assets and quality and the activities, materials, labor, budget, and tools needed to assess and manage them. Systems integration remains an elusive goal. Although a few states are pursuing integrated asset management systems, recent leaps forward have been frequently limited to integration of management systems within a single functional area, e.g., integration of Pontis for bridge management with Virtis to bridge load rating. In that decentralized context, this paper presents several leading examples or best practices in asset and maintenance quality management in various areas of maintenance where environmental aspects that are difficult to quantify have begun to be incorporated.
Life-Cycle Economic Comparison of Common Signpost Materials and Types
Authors: Raman Sankara , Rys Margaret J. , Russell Eugene R.
Published: January 2019

There is a wealth of information related to life-cycle costs of different sign sheeting materials and considerable information on common signposts, but there is little or no information about the life-cycle costs of different types of signposts. The primary objective of this research was to determine the best cost-effective policy, consistent with safety, for signpost materials and types used on state highways in Kansas. From the initial literature review, a matrix was constructed detailing the various materials used for signposts by each state. This was followed with a survey questionnaire to gather information on what posts other states were using for three major types of signs used in Kansas. From the data obtained from the state departments of transportation, test installations were carried out by three vendors. Life-cycle economic analysis was conducted, taking into consideration the labor, equipment, and time requirements for the initial installation and the replacement. Among the four systems compared for a single signpost, the Poz-Loc Socket System is the most cost-effective alternative in life-cycle costs, followed by the Break-Out Sign Support System, the 4″ x 4″ x 14′ wood post, and the Telespar anchor-driven unit. Among the three systems compared for a double signpost, the Poz-Loc Slipbase System is the most cost-effective alternative, followed by the Telespar Slipbase System, and the double 4″ x 6″ x 16′ wood post. The present worth analysis and sensitivity analysis, conducted according to varying the interest rate, did not have any significant effect in changing the cost-effective alternative.
Work Zone Optimization for Two-Lane Highway Resurfacing Projects with an Alternate Route
Authors: Chen Chun-Hung (Peter) , Schonfeld Paul , Paracha Jawad
Published: January 2019

Pavements on two-lane two-way highways are usually resurfaced by closing one lane at a time. Vehicles then travel in the remaining lane along the work zone, alternating directions within each control cycle. In an earlier work, Chen and Schonfeld developed a work zone optimization model for two-lane highways with time-dependent inflows and no detours, based on simulated annealing. In this paper, several alternatives are evaluated, defined by the number of closed lanes and fractions of traffic diverted to alternate routes. The algorithm referred to as SAUASD (simulated annealing for uniform alternatives with a single detour) is developed to find the best single alternative within a resurfacing project. The algorithm referred to as SAMASD (simulated annealing for mixed alternatives with a single detour) is developed to search through possible mixed alternatives and their diverted fractions, to minimize total cost, further including agency cost (resurfacing cost and idling cost) and user cost (user delay cost and accident cost). Thus, traffic management plans are developed with uniform or mixed alternatives within a two-lane highway resurfacing project.
Evaluation of Effectiveness of Automated Work Zone Information Systems
Authors: Chu Lianyu , Kim Hee-Kyung , Chung Younshik , Recker Will
Published: January 2019

With the advancement of the intelligent transportation system technologies, some automated work zone information systems (AWISs) have been developed and deployed in the field. Their purpose is to provide useful real-time traffic information to motorists as they approach or pass through a work zone. Several studies have been conducted to evaluate AWIS, and most of those studies paid attention to the evaluation of system functionality and reliability. This paper focuses on the evaluation of the effectiveness of the computerized highway information processing system deployed in Southern California, pertaining to the aspects of safety and diversion effects, as well as travelers’ acceptance. Evaluation results showed most driver survey respondents liked the system, which was found to be effective in diverting traffic and promoting smoother traffic flow during congested periods.
Effect of Continuous Shoulder Rumble Strips and Pavement Marking on Lateral Placement of Vehicles
Authors: Taylor William C. , Abu-Lebdeh Ghassan , Rai Sachin
Published: January 2019

Shoulder rumble strips and enhanced pavement markings were two key areas identified by AASHTO to reduce runoff-road collisions. The Michigan Department of Transportation is currently testing the effectiveness of placing shoulder rumble strips close to the edge of travel lanes and painting a line on the rumble strip to improve the retroreflective properties of the line. Two issues arise from placing the rumble strips closer to the edge line and moving the paint line onto the rumble strip: the potential increased noise when vehicles crossed over the rumble strips and damage to the pavement if vehicles moved closer to the construction joint between the travel lane and the shoulder. This study found that simply moving the paint line onto the rumble strips resulted in vehicles moving slightly closer to the edge of the travel lane. However, maintaining the current edge line and adding an additional paint line on the rumble strip resulted in vehicles moving away from the edge of the pavement and thus reduced noise and potential damage to the pavement.