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This study explores speed choice behavior of travelers under realistic and fabricated Dynamic Message Signs (DMS) content. Using web-based survey information of 4,302 participants collected by Amazon Mechanical Turk in the United States, we develop a set of multivariate latent-based ordered probit models participants. Results show female, African-Americans, drivers with a disability, elderly, and drivers who trust DMS are likely to comply with the fabricated messages. Drivers who comply with traffic regulations, have a good driving record, and live in rural areas, as well as female drivers are likely to slow down under fabricated messages. We highlight that calling or texting, taking picture, and tuning the radio are distracting activities leading drivers to slow down or stop under fictitious scenarios. [ABSTRACT FROM AUTHOR]

Highway-rail grade crossing (HRGC) crashes continue to be the major contributors to rail causalities in the United States and have been intensively researched in the past. Data-mining models focus on prediction while dominant general linear models focus on model and data fitness. Decision makers and traffic engineers rely on prediction models to examine at-grade crash frequency and make safety improvement. The gradient boosting (GB) model has gained popularity in many research areas. In this study, to fully understand the model performance on HRGC accident prediction performance, the GB model with functional gradient descent algorithm is selected to analyze crashes at highway-rail grade crossings (HRGCs) and to identify contributor factors. Moreover, contributors' importance and partial-dependent relations are generated to further understand the relationship of identified contributors and HRGC crash likelihood to concur "black box" issues that most machine learning methods face. Furthermore, to fully demonstrate the model's prediction performance, a comprehensive model prediction power assessment based on six measurements is conducted, and the prediction performance of the GB model is verified and compared with a decision tree model as a reference due to their popularity and comparable data availability. It is demonstrated that the GB model produces better prediction accuracy and reveals nonlinear relationships among contributors and crash likelihood. In general, HRGC crash likelihood is significantly impacted by several traffic exposure factors: highway traffic volume, railway traffic volume, and train travel speed and others. [ABSTRACT FROM AUTHOR]

The article comments on the importance of campus safety at public universities and community colleges in Oregon. Topics discussed are campus safety laws, statutory scope of authority of community colleges and university police departments, traffic control powers of community colleges, distinction between college peace officer and university police officer, citizens arrest statute, and infrastructural approach to increase campus safety and decrease liability and authoritative overreach.

Although freeway traffic system is conducted with a repeatable pattern day-to-day, the initial volume/or speed and the desired density of the traffic flow may vary with days due to the external disturbances. In this paper, a new linear data-model based adaptive iterative learning control (LDM-AILC) is proposed to address ramp metering in a macroscopic level freeway environment. A linear data-model is developed for the nonlinear macroscopic traffic flow model by introducing an equivalent dynamical linearization approach in the time domain. Then the LDM-AILC is designed with a feedback control law and a parameter updating law. The proposed scheme is data-driven intrinsically, where only the input and output data are required for the controller design and analysis. The convergence is shown by rigorous analysis without any identical conditions exposed on both the initial state and the reference trajectory. Extensive simulation results are provided to verify the effectiveness of the proposed LDM-AILC. [ABSTRACT FROM AUTHOR]

This article studies a capacitated fixed-charge multiperiod location–transportation problem in which, while the location and capacity of each facility must be determined immediately, the determination of the final production and distribution of products can be delayed until actual orders are received in each period. In contexts where little is known about future demand, robust optimization, namely using a budgeted uncertainty set, becomes a natural method for identifying meaningful decisions. Unfortunately, it is well known that these types of multiperiod robust decision problems are computationally intractable. To overcome this difficulty, we propose a set of tractable conservative approximations for the problem that each exploit to a different extent the idea of reducing the flexibility of the delayed decisions. While all of these approximation models outperform previous approximation models that have been proposed for this problem, each also has the potential to reach a different level of compromise between efficiency of resolution and quality of the solution. A row generation algorithm is also presented to address problem instances of realistic size. We also demonstrate that full flexibility is often unnecessary to reach nearly, or even exact, optimal robust locations and capacities for the facilities. Finally, we illustrate our findings with an extensive numerical study where we evaluate the effect of the amount of uncertainty on the performance and structure of each approximate solution that can be obtain d. [ABSTRACT FROM AUTHOR]

We study an emergency response network design problem that integrates relief (supply) and evacuation (demand) sides under disaster location and intensity uncertainties which, in turn, dictate uncertainty in terms of the location and amount of demand. Representing these uncertainties by discrete scenarios, we present a stochastic programming framework in which two second stage objectives, the average and worst case costs, are combined. In our model, we minimize, over all of the scenarios, the fixed costs of opening supply centers and shelters, and the weighted sum of average and worst case flow costs. Thus, the model gives the decision maker the flexibility to put relative emphasis on the worst case and average flow cost minimization and explore outcomes in terms of total costs and network configurations. To solve large scale instances with varying relative weights, we devise alternative Benders Decomposition approaches. We implement these by using an advanced callback feature of the solver while simultaneously incorporating several performance-enhancing steps that help to improve runtimes significantly. We conduct a detailed computational study to highlight the efficiency of our proposed solution methodology. Furthermore, we apply our approach in a realistic case study based on Geographical Information Systems data on coastal Texas and present interesting insights about the problem and the resulting network structures for varying weights assigned to objectives. [ABSTRACT FROM AUTHOR]

Urban transportation systems are vulnerable to congestion, accidents, weather, special events, and other costly delays. Whereas typical policy responses prioritize reduction of delays under normal conditions to improve the efficiency of urban road systems, analytic support for investments that improve resilience (defined as system recovery from additional disruptions) is still scarce. In this effort, we represent paved roads as a transportation network by mapping intersections to nodes and road segments between the intersections to links. We built road networks for 40 of the urban areas defined by the U.S. Census Bureau. We developed and calibrated a model to evaluate traffic delays using link loads. The loads may be regarded as traffic-based centrality measures, estimating the number of individuals using corresponding road segments. Efficiency was estimated as the average annual delay per peak-period auto commuter, and modeled results were found to be close to observed data, with the notable exception of New York City. Resilience was estimated as the change in efficiency resulting from roadway disruptions and was found to vary between cities, with increased delays due to a 5% random loss of road linkages ranging from 9.5% in Los Angeles to 56.0% in San Francisco. The results demonstrate that many urban road systems that operate inefficiently under normal conditions are nevertheless resilient to disruption, whereas some more efficient cities are more fragile. The implication is that resilience, not just efficiency, should be considered explicitly in roadway project selection and justify investment opportunities related to disaster and other disruptions. [ABSTRACT FROM AUTHOR]

This is the sixth in a series of reviews of research on graduated driver licensing (GDL) published in the Journal of Safety Research , the present review covering the period mid-2012 through 2016. In the two decades since GDL programs began to be introduced on a widespread basis in the United States, a vast amount of research has been published. The current review discusses recent research and the present state of knowledge on the following topics: characteristics of the novice driver population; effects of GDL on crashes for ages 16–19; the learner and intermediate periods; night and passenger restrictions; cellphone laws; GDL for older novices; enforcement of GDL rules; and programs attempting to influence GDL compliance and safe driving practices in general. GDL stands out as a successful policy for reducing teen driver crashes and is worth building on to extend its benefits. Strengthening existing GDL programs has the most potential for producing further crash reductions. [ABSTRACT FROM AUTHOR]

The article examines challenges facing regional transportation planners in the U.S. in an era characterized by uneven growth and accelerating impacts of climate change. Topics discussed include ways in which growing inequality and technological change affect the priorities for transportation planning; and metropolitan transportation systems in New York region.

The article highlights the role of traffic enforcement, analyzes its efficacy to deter dangerous driving, and suggests a new framework for traffic enforcement suited to the goals of Vision Zero. It suggests that primary goal of Vision Zero-related traffic enforcement must be to create long-lasting deterrence of dangerous driving behavior.

Approximately 11% of bridges in the United States are categorized as structurally deficient and there is a marked need of more accurately evaluating true structural capacity. Structural Health Monitoring (SHM) systems can provide a timely indication of the need for maintenance, repair, rehabilitation and replacement of bridges and can greatly improve the apportionment and management of limited resources. This paper presents an Automated Ambient Traffic (AAT) approach for determining load rating of bridges monitored by the BECAS SHM system under ambient traffic. The AAT approach was developed through a process integration of truck detection, bridge model calibration, and bridge load rating: (1) the quasi-static bridge strain response and the characteristics of associated trucks are collected; (2) multiple trucks are randomly sampled from a historic Weigh-In-Motion (WIM) database; and (3) for each combination of strain response and truck selection, an Finite Element (FE) model is calibrated and used to calculate a load rating. Sampling strategies were discussed for appropriately quantifying the influence of uncertainties of truck characteristics on the calibration and load rating results. To demonstrate this approach, a sample three-span, five-girder, and two-lane steel girder/concrete deck (I-80) bridge was utilized. A load rating of the I-80 Bridge using the Traditional Known Truck (TKT) approach was performed to provide benchmark results. The results of the calibration and load rating using the AAT approach were derived using three different sampling strategies and compared to those using the TKT approach. The sampling strategy, selecting strain response with a spectrum of higher peak girder strains, associated trucks with a spectrum of higher gross vehicle weights, and two truck events on south and north lanes respectively for a calibration, resulted in the best calibration and load rating results. It was concluded that the AAT approach using the BECAS SHM system is a reliable method for continuously estimating the load carrying capacity of bridges. [ABSTRACT FROM AUTHOR]

Users of International Land Ports of Entries (LPOEs) at the US – Mexico border experience excessive wait times on a daily basis. This contributes to the increased transportation costs, and also generates health and environmental problems in border regions. Traffic simulation models are effective tools for evaluating passenger vehicle, pedestrian and commercial traffic operations. These tools can be used to assess various scenarios and visualize current traffic conditions. Results obtained from these tools should be taken into account in congestion relief decision making processes. The research team developed, calibrated and validated three traffic models of the Ysleta-Zaragoza LPOE using three different software packages (i.e., TransModeler, VISSIM, and Aimsun). This paper presents advantages and disadvantages of each tool when modeling international LPOEs. Results presented herein can be used by practitioners to decide which tool should to be used for modeling LPOEs at the U.S. – Mexico border. [ABSTRACT FROM AUTHOR]

Air travel has been a major transportation for commerce and tour in many countries. As the demand of air traffic has been increasing, air traffic management has confronted with poverty of handling the increase of the demand of runway facilities where congestion often takes place. In order to cope with such problems, runway efficiency enhancement or capacity increasing are taken into account. In air traffic management, the effective air space utilization and air control workload management can be improved by the use of many up-to-date technologies in forms of decision support tools. This study developed a computer-aided decision support model in the form of integer programming. The purpose of the model was to allocate airplanes arrival at U.S. Center-TRACON airspace to enter feeder gates and to design optimal routes along the track to runway. Results of optimal path of the airplanes throughout the TRACON air space system which yield a minimum delay were presented. [ABSTRACT FROM AUTHOR]

Introduction Based on the Federal Railway Administration (FRA) database, approximately 62% of the collisions at highway-rail crossings occurred at locations with active controls (gate and flashing lights), followed by passive controls (cross bucks and stop signs) with approximately 28% of accidents. Method The study applied an ordered probit model to explore the determinants of driver injury severity under various control measures at highway-rail grade crossing in the United States. Results The analysis found that schedule factor (peak hour), visibility, motor vehicle speed, train speed, driver’s age, area type, traffic volume and highway pavement impact driver injury severity at both active and passive highway-rail crossings. Practical Applications For both active and passive control highway-rail grade crossings, speed control for both trains and vehicles will significantly reduce driver injury severity. However, the level of influence by vehicle speed and train speed at passive control is higher compared with active control. Paving highways at highway-rail grade crossings will also help to reduce driver injury severity at highway-rail crossing accidents. [ABSTRACT FROM AUTHOR]

The author offers a response to a commentary made by Professor Dan Subotnik on his article "The Emerging American Police State," published within the issue. He says that he wrote the article to address important issues of constitutional dimension. These issues include the relationship between traffic fines and race and ethnicity, and the impact of the proliferation of stop signs on the environment and the economy.

Hybrid electric vehicles (HEVs) are considered to be one of the energy-efficient technologies for near-term sustainability of the transportation sector. Over the years, research has focused on improving fuel economy (FE) for a given drive cycle, but FE variability over a realistic range of real-world driving patterns has been generally overlooked, and this can lead to FE benefits not being fully realized in real-world usage. No systematic methodology exists to reduce FE variability by design optimization of powertrain components. This study proposes a methodology of powertrain component optimization to reduce the FE variability due to variations in driving patterns. In the proposed methodology, powertrain components are optimum over a range of driving patterns of different traffic conditions and driving styles simultaneously. The proposed methodology demonstrates the potential to reduce FE variability by up to 34% over six driving patterns of different traffic conditions and driving styles. [ABSTRACT FROM PUBLISHER]

This paper proposes an en route speed reduction to complement current ground delay practices in air traffic flow management. Given a nominal cruise speed, there exists a bounded range of speeds that allows aircraft to fly slower with the same or lower fuel consumption than the nominal flight. Therefore, flight times are increased and delay can be partially performed in the air, at no extra fuel cost for the operator. This concept has been analyzed in an initial feasibility study, computing the maximum amount of delay that can be performed in the air in some representative flights. The impact on fuel consumption has been analyzed, and two scenarios are proposed: the flight fuel remains the same as in the nominal flight, and some extra fuel allowance is permitted in order to face uncertainties. Results show significant values of airborne delay that may be useful in many situations, with the exception of short hauls where airborne delay may be too short. If cruise altitude is changed, the amount of airborne delay increases, since changes in cruise speed modify the optimal flight altitudes. From the analyzed flights, a linear dependency is found relating the airborne delay with the amount of extra fuel allowance. [ABSTRACT FROM AUTHOR]

Stop signs are the primary form of traffic control in the United States. However, they have a tendency to be much less effective than other forms of traffic control like traffic lights. This is due to their smaller size, lack of lighting, and the fact that they may become visually obscured from the road. In this paper, we offer a solution to this problem in the form of a mobile application implemented in the Android platform: Stop Watcher. It is designed to alert a driver when they are approaching a stop sign using a voice notification system (VNS). A field test was performed in a snowy environment. The test results demonstrate that the application can detect all of the stop signs correctly, even when some of them were obstructed by the snow, which in turn greatly improves the user awareness of stop signs. [ABSTRACT FROM AUTHOR]

Recently, the IntelliDrive initiative has been proposed by the US Department of Transportation (USDOT) to enhance on-road safety and efficiency. In this study, we provide a mathematical framework which predicts the effect of such technologies on the efficiency of multilane highway systems prior to their real-life deployment. Our study shall encompass mixed traffic conditions in which a variety of assisted, automated and unequipped vehicles coexist. We show that intervehicular communications improves the flow of vehicles by reducing the perception-reaction (P-R) times of drivers and, in some cases, allowing for more efficient lane-changing operations. As we shall see, unlike the latter, the former effect of IntelliDrive on driver P-R time is always there, regardless of the specific traffic conditions. [ABSTRACT FROM AUTHOR]

This paper presents a new integer programming (IP) model for large-scale instances of the air traffic flow management (ATFM) problem. The model covers all the phases of each flight--i.e., takeoff, en route cruising, and landing--and solves for an optimal combination of flow management actions, including ground-holding, rerouting, speed control, and airborne holding on a flight-by-flight basis. A distinguishing feature of the model is that it allows for rerouting decisions. This is achieved through the imposition of sets of "local" conditions that make it possible to represent rerouting options in a compact way by only introducing some new constraints. Moreover, three classes of valid inequalities are incorporated into the model to strengthen the polyhedral structure of the underlying relaxation. Computational times are short and reasonable for practical application on problem instances of size comparable to that of the entire U.S. air traffic management system. Thus, the proposed model has the potential of serving as the main engine for the preliminary identification, on a daily basis, of promising air traffic flow management interventions on a national scale in the United States or on a continental scale in Europe. [ABSTRACT FROM AUTHOR]

A safety and security issue of concern for traffic managers and homeland security is the monitoring of flows on “planar surfaces,” such as ports and border areas. This article addresses the problem of locating surveillance radars to cover a given target surface that may have barriers through which radar signals cannot penetrate. The area of coverage of a radar is assumed to be a disc, or a partial disc when there are barriers, with a known radius. The article shows that the corresponding location problems relate to two well studied problems: the set-covering model and the maximal covering problem. In the first problem, the minimum number of radars is to be located to completely cover the target area; in the second problem a given number M of radars are to be located to cover the target area as much as possible. Based on a discrete representation of the target area, a Lagrangian heuristic and a two-stage procedure with a conquer-and-divide scaling are developed to solve the above two models. The computational experiences reported demonstrate that the developed method solves well the radar location problems formulated here. [ABSTRACT FROM AUTHOR]

The article discusses embedded multimedia processors to be used for road-traffic parameter estimation. These multimedia processors will provide the basis for future intelligent transportation electronic installations as directed by the U.S. Department of Transportation. Multimedia processors also provide special support for video applications.

Abstract: Enhancing airport runway safety is a difficult problem because runway accidents are rare events. Nonetheless, investments are being directed at improving safety for US airport ground traffic control systems. This paper shows that under these circumstances it is difficult to assess and measure the added safety offered by new replacement systems. We develop a framework for introducing and sequencing system improvements to provide greater assurances in enhancing safety. This framework shows how a new method can first be introduced as a secondary system, to test and verify its efficacy prior to its adoption as a primary system. [Copyright &y& Elsevier]

Traffic-generated air pollution and noise have both been linked to cardiovascular morbidity. Since traffic is a shared source, there is potential for correlated exposures that may lead to confounding in epidemiologic studies. As part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), 2-week NO and NO2 concentrations were measured at up to 105 locations, selected primarily to characterize gradients near major roads, in each of 9 US communities. We measured 5-min A-weighted equivalent continuous sound pressure levels (L eq) and ultrafine particle (UFP) counts at a subset of these NO/NO2 monitoring locations in Chicago, IL (N=69 in December 2006; N=36 in April 2007) and Riverside County, CA (N=46 in April 2007). L eq and UFP were measured during non-“rush hour” periods (10:00–16:00) to maximize comparability between measurements. We evaluated roadway proximity exposure surrogates in relation to the measured levels, estimated noise–air pollution correlation coefficients, and evaluated the impact of regional-scale pollution gradients, wind direction, and roadway proximity on the correlations. Five-minute L eq measurements in December 2006 and April 2007 were highly correlated (r=0.84), and measurements made at different times of day were similar (coefficients of variation: 0.5–13%), indicating that 5-min measurements are representative of long-term L eq. Binary and continuous roadway proximity metrics characterized L eq as well or better than NO or NO2. We found strong regional-scale gradients in NO and NO2, particularly in Chicago, but only weak regional-scale gradients in L eq and UFP. L eq was most consistently correlated with NO, but the correlations were moderate (0.20–0.60). After removing the influence of regional-scale gradients the correlations generally increased (L eq–NO: r=0.49–0.62), and correlations downwind of major roads (L eq–NO: r=0.53–0.74) were consistently higher than those upwind (0.35–0.65). There was not a consistent effect of roadway proximity on the correlations. In conclusion, roadway proximity variables are not unique exposure surrogates in studies of endpoints hypothesized to be related to both air pollution and noise. Moderate correlations between traffic-generated air pollution and noise suggest the possibility of confounding, which might be minimized by considering regional pollution gradients and/or prevailing wind direction(s) in epidemiologic studies. [Copyright &y& Elsevier]

The article presents the contents of the U.S. National Highway Traffic Safety Administration (NHTSA)'s document, the Novice Teen Driver Education and Training Standards. The forward section discusses the value of novice teen driver training and education for American teenagers. The Novice Teen Driver Education and Training Administrative Standards set forth in the document serve to guide all novice teen driver education and training programs in states striving to provide quality, consistent driver education and training.

BACKGROUND: Traffic-related air pollution has been associated with adverse health outcomes, and the immune system may be a biologic mediator of health effects. OBJECTIVES: We analyzed associations between living near major roads and immune status as measured by five immune assays. We hypothesized that living near a freeway, arterial, or truck route would be associated with increased inflammation and decreased immune function. METHODS: We used a geographic information system (GIS) to determine residential proximity to major roads among 115 postmenopausal, overweight women in the greater Seattle, Washington (USA), area whose immunity was assessed at the baseline visit of an exercise intervention trial. We evaluated three inflammatory markers (C-reactive protein, serum amyloid A, and interleukin-6) and two functional assays of cellular immunity [natural killer (NK) cell cytotoxicity and T-lymphocyte proliferation]. RESULTS: Women living within 150 m of arterial roads had 21% lower NK cytotoxicity compared with women who lived farther from an arterial [mean cytotoxicity, 19.5%; 95% confidence interval (CI), 15.6--23.5%; vs. mean cytotoxicity, 24.8%; 95% CI, 22.0--27.5%], after adjustment for both individual-level and census tract--level demographic characteristics. This association was limited to women who reported exercising near traffic. Fewer women lived near freeways and truck routes. Markers of inflammation and lymphocyte proliferation did not consistently differ according to proximity to major roads. CONCLUSIONS: If the observed association between residential proximity to traffic and decreased NK cytotoxicity is confirmed in other populations, our results may have implications for local land use policy. [ABSTRACT FROM AUTHOR]

Traffic data in general and traffic volume in particular are collected to determine the use and performance of the roadway system. Due to budget limitations, traffic volume cannot be counted day by day for every roadway within the state. Therefore, the volume on roadways without automatic traffic recorders (ATRs) can be determined by taking portable short-duration counts and using adjustment factors to produce annual average daily traffic (AADT) at a specific location. This study presents a statistical practical methodology that develops traffic pattern groups (TPGs) by combining roadways with similar traffic characteristics such as volume, seasonal variation, and land use in Delaware, USA. Monthly seasonal adjustment factors and their coefficient of variance (FCV) are analyzed for each group. To meet the desired confidence level and precision intervals, the TPGs’ ATR inventory is examined such that the required sample size is determined by the critical month. [ABSTRACT FROM AUTHOR]

The article discusses the mandate for federal corporate average fuel economy (CAFE) standards for light trucks in the U.S. The Ninth Circuit reviewed the National Highway Traffic Safety Administration's (NHTSA) Final Rule from the lawsuit, Center for Biological Diversity v. National Highway Traffic Safety Administration. Petitioners challenged the standards under the Energy Policy and Conservation Act (EPCA) and the National Environmental Policy Act (NEPA). The court found a number of problems with the standards as adopted and held that NHTSA should have included the impacts of climate change in its analysis.

The article presents information on the result of a survey on the future of driver education. When asked to describe the role of driver education in the larger picture of highway safety efforts in the U.S. today, some respondents said that driver education today must resolve the issues of behavior and attitude that are not being addressed at home. According to some respondents, the important values of driver education in the U.S. are safety, attitude, quality, and worth, communication, and prevention.

Abstract: Objective: The initial months of licensure are especially hazardous for teenagers. Factors leading to crashes of novice 16-year-old drivers were identified. Method: Sixteen year-olds in Connecticut who were involved in nonfatal crashes during the first 8 months of licensure were interviewed, and police crash reports were examined. Crash types and contributing factors were identified. Results: Three-fourths of the crash-involved teenagers were at fault. Their crashes resulted primarily when they ran off the road, rear ended another vehicle, or collided with another vehicle that had the right-of-way. Three factors contributed about equally to their crashes: failing to detect another vehicle or traffic control, speeding, and losing control of the vehicle or sliding. Slippery roads also were an important factor. Most failures to detect another vehicle or traffic control involved not looking thoroughly, distraction, or inattention. Discussion: Based on the findings, potential countermeasures for reducing crashes of novice teenage drivers include adequate practice driving, in-vehicle monitoring devices, and electronic stability control. Impact on industry: More than half of the nonfatal, at-fault crashes of newly licensed 16-year-old drivers involved more than one contributing factor including speed, loss of control, and slippery roads. Efforts to reduce teenage crashes should focus on these factors. [Copyright &y& Elsevier]

Abstract: Problem: The driver celeration behavior theory predicts that celerations are associated with incidents for which the driver has some responsibility in causing, but not other incidents. Method: The hypothesis was tested in 25 samples of repeated measurements of bus drivers’ celeration behavior against their incidents for two years. Results: The results confirmed the prediction; in 18 samples, the correlation for culpable incidents only was higher than for all incidents, despite the higher means of the latter. Non-culpable incidents had correlations close to zero with celeration. Discussion: It was pointed out that most individual crash prediction studies have not made this differentiation, and thus probably yielded underestimates of the associations sought, although the effect is not strong, due to non-culpable accident involvements being few (less than a third of the total). The methods for correct identification of culpable incident involvements were discussed. [Copyright &y& Elsevier]

Abstract: Introduction: Most studies that evaluate the relationship between economic conditions and traffic fatalities focus on the time-series relationship between the two factors. This analysis considers the cross-sectional perspective by estimating the cross-county correlation between per capita income and fatalities per vehicle mile traveled (VMT) in Ohio. Method: The empirical model employed in this analysis allows for interaction effects between per capita income and highway usage, in the determination of fatality rates. Results: The resultant least squares estimates indicate that a significant interaction effect exists between per capita income and the percentage of highway VMT, indicating a nonlinear correlation between per capita income and fatality rates. This correlation rises as the proportion of VMT on highways rises, such that there is an inverse relationship with fatality rates when the highway share of county VMT is low and a direct relationship with fatality rates when the highway share of county VMT is high. Additionally, population density, the presence of interstate highways in rural counties, the prior prevalence of severe alcohol abuse, and the proportion of teen drivers all proved to be significant correlates with county fatality rates. Conclusions: These observations suggest factors that state and federal policy makers should consider when allocating resources that impact (whether directly or indirectly) traffic fatalities. [Copyright &y& Elsevier]

Abstract: Introduction: Awareness about worker safety in nighttime construction has been a major concern because it is believed that nighttime construction creates hazardous work conditions. However, only a few studies provide valuable comparative information about accident characteristics of nighttime and daytime highway construction activities. Method: This study investigates fatal accidents that occurred in Illinois highway work zones in the period 1996–2001 in order to determine the safety differences between nighttime and daytime highway construction. The lighting and weather conditions were included into the study as control parameters to see their effects on the frequency of fatal accidents occurring in work zones. Results: According to this study, there is evidence that nighttime construction is more hazardous than daytime construction. The inclusion of a weather parameter into the analysis has limited effect on this finding. Impact on Industry: The study justifies establishing an efficient work zone accident reporting system and taking all necessary measures to enhance safety in nighttime work zones. [Copyright &y& Elsevier]

Road traffic is one of the major anthropogenic emission sectors for NOx, CO and NMHCs (non-methane hydrocarbons). We applied ECHAM4/CBM, a general circulation model coupled to a chemistry module, which includes higher hydrocarbons, to investigate the global impact of 1990 road traffic emissions on the atmosphere. Improving over previous global modelling studies, which concentrated on road traffic NOx and CO emissions only, we assess the impact of NMHC emissions from road traffic. It is revealed that NMHC emissions from road traffic play a key role for the impact on ozone. They are responsible for (indirect) long-range transport of NOx from road traffic via the formation of PAN, which is not found in a simulation without NMHC emissions from road traffic. Long-range transport of NMHC-induced PAN impacts on the ozone distribution in Northern Hemisphere regions far away from the sources, especially in arctic and remote maritime regions. In July total road traffic emissions (NOx, CO and NMHCs) contribute to the zonally averaged ozone distribution by more than 12% near the surface in the Northern Hemisphere midlatitudes and arctic latitudes. In January road traffic emissions contribute near the surface in northern and southern extratropics more than 8%. Sensitivity studies for regional emission show that effective transport of road traffic emissions occurs mainly in the free troposphere. In tropical latitudes of America up to an altitude of 200 hPa, global road traffic emissions contribute about 8% to the ozone concentration. In arctic latitudes NMHC emissions from road transport are responsible for about 90% of PAN increase from road transport, leading to a contribution to ozone concentrations of up to 15%. [ABSTRACT FROM AUTHOR]

The article discusses the impact of urban trees on the traffic plans of the cities in the U.S. According to the research, the U.S. transportation agencies during late 20th century focused on developing traffic plans and practices that will provide high levels of traffic capacity and safety for roads at lower cost.

Transportation engineering constitutes a required portion of the civil engineering curriculum at over three-fourths of undergraduate civil engineering programs in the United States. The input of practicing transportation engineers is a critical source of information in determining the content of the first course in transportation engineering. A new survey was conducted in which respondents ranked 31 potential course topics by importance. The results are compared to a similar survey conducted 20 years before to determine which topics have increased in importance, which have become less critical to cover, and which continue to remain of high priority. Topics such as traffic safety and traffic flow characteristics are of considerably higher priority today than 20 years ago, while topics such as geometric design of highways and highway capacity studies continue to be of great importance. Preparation for follow-up and graduate coursework, for the Fundamentals of Engineering and Professional Engineer examinations, and issues of local setting are also considerations in determining the content of the first course in transportation engineering. [ABSTRACT FROM AUTHOR]

The article discusses the development of an agent-based control for networked traffic management systems in the United States. Control algorithms have been developed to run various industrial devices, including intersection traffic controllers. The agent-based control method decomposes a control algorithm into many simple task-oriented control agents distributed over a network, generally a wide-area network. Control agents that can be deployed and replaced over the network as operating conditions vary will run network-enabled devices. In this way, a network-enabled device can operate on a control on demand basis.

The major initiatives of the U.S., Europe, and Japan in the early 1990s to exploit communication, control, and computer advances to make transportation more efficient, reliable, and safe, is embodied in the U.S. Intelligent Transportation System (ITS) program. To help fulfill the promises of ITS, the Advanced Traffic and Logistics Algorithms and Systems research center is developing and testing the Real-Time Hierarchical Optimized Distributed Effective System (RHODES) traffic control system. In this article, it is the intention of the author to examine how RHODES will play a major role in the realization of future Advanced Traffic Management Systems, a major component of ITS.

In spring 2004, the Hudson Valley Transportation Management Center (TMC) is beginning permanent operations in a new state-of-the-art facility in Hawthorne, New York. First conceived in the early 1990s, the Hudson Valley TMC, and the intelligent transportation system (ITS) of which it's part, are expected to reduce the number and impact of highway incidents. The National ITS Architecture uses its term physical entities to describe the subsystems of the ITS and the entities that interface to the ITS. The primary physical entities of the Hudson Valley ITS are the TMC, the Field Data Network and the communication infrastructure.

The Federal Aviation Administration's effort to automate air traffic control (ATC) requires that the functionality provided today be captured in future systems. We report the first quantitative naturalistic observation of paper flight progress strip interactions during operational use. Strip use was similar in a variety of situations, but some uses varied as a function of altitude, staffing, or the cooperative style used by controller teams. Design of automation should proceed by prioritizing changes based on frequency of use and importance and should ensure that an effective method of interacting with flight information is incorporated. In addition to applied relevance to the ATC domain, the results touch on several theoretical concerns relevant to dynamic environments. Actual and potential applications of this research include the establishment of a database of strip activity and an arsenal of information valuable to system designers. [ABSTRACT FROM AUTHOR]

Considers the exhibition "The Street" by Claes Oldenburg as a means of thinking about the possibilities for and limitations of New York City, in view of the giant, highly controversial, program of modernist urban renewal then reshaping much of the city. Significance of the book "The Steadyflow Traffic System," by Fritz Marcher to U. S. urban traffic engineering; Description of the show; Information on a symposium attended by Oldenburg.

This paper reviews the legal status of traffic calming in the US. It covers case law relating to legal authority, tort liability, and takings. It also covers damage claims against 20 localities that have been particularly active in traffic calming. [ABSTRACT FROM AUTHOR]

This paper explores impediments to context-sensitive design of main streets, and suggests ways of overcoming them. It is based on a guidebook for the New Jersey Department of Transportation titled Flexible Design of New Jersey's Main Streets. Contrary to conventional wisdom, minimum design values in the American Association of State Highway and Transportation Officials' A Policy on Geometric Design of Highways and Streets (AASHTO's 2001 Green Book) do not appear to constrain main street design. Nor do tort liability considerations in most states, primarily because of broad design immunity under state statutes and case law. From case studies conducted for this project, the real impediments to context-sensitive design appear to be: state design standards in excess of AASHTO minimums, and in excess of what is required for driver safety in low-speed environments; minimum level-of-service standards adopted for driver convenience, which may be less important on main streets than pedestrian safety and comfort; over-reliance on typical sections from state roadway design manuals, when multiple cross sections tailored to abutting land uses would be more appropriate; and reluctance to seek design exceptions for purposes of "context savings," only for purposes of cost savings. Additional impediments include application of new construction standards to 3R and reconstruction projects, even when a street's history suggests no safety problem; misclassification of streets as rural and application of rural design standards to them, when they in fact run through small urban places; misclassification of streets as arterials, when bypasses and other parallel improvements have caused main streets to function as local streets; and reluctance of state DOTs to assume maintenance responsibilities for street trees, landscaped medians and bulbouts, textured crosswalks, and similar common main street improvements. Case studies from Albuquerque, NM; Anchorage, AK; Brooklyn, CT; Saratoga... [ABSTRACT FROM AUTHOR]