Bureau of Transportation Statistics

This paper presents an assessment of the effects of terrorism on tourism by using time series methods, namely the ARMAX (autoregressive moving average with explanatory variables) model. This is a single-equation approach, which has the ability to provide impact analysis easily. The use of the ARMAX model allows for the general shape of the lag distribution of the impacts of the explanatory variables based on the ratio of lag polynomials for the independent and dependent variables. The ARMAX models, like the ARIMA models, provide for a short-term assessment of terrorist incidents on tourism.

INTRODUCTION: Midair collisions cause loss of life and property and undermine general aviation; they also represent failures of the see-and-avoid concept in air traffic control. This study identifies limitations of the see-and-avoid concept. METHODS: Analysis of National Transportation Safety Board data on 159 U.S. civil aviation midair collisions and limitations of the see-and-avoid concept. RESULTS: On average, there were 15.6 midair collisions annually from 1991 through 2000. At least one aircraft was maneuvering in 88% of collisions, and both in 70%. There were 77% that involved arrival to, departure from, or flight over an airport, with 61% in the traffic pattern. Head-tail collisions were more frequent in the traffic pattern than out (28.3%, 2.8%, p < 0.05). Other horizontal convergence angles were equally frequent in or out of the pattern: head-on (8.3%, 11.0%), obtuse (11.0%, 8.3%), and acute (13.8%, 16.6%). DISCUSSION: Because the relative bearing to each aircraft on an unaccelerated collision course is constant, pilots sometimes cannot see converging aircraft when climbing, descending, or level. Even if a converging aircraft is unobstructed, it appears small, motionless, camouflaged, and inconspicuous until imminent impact. A statistical model reveals that the probabilities of seeing and avoiding a converging 40-ft aircraft, for an optimal observer or theoretical pilot scanning 2/3 or 1/3 of the time, respectively, are less than 0.91, 0.60, 0.30 at 200 kn; 0.49, 0.32, 0.16 at 300 kn; 0.28, 0.18, 0.09 at 400 kn; and 0.15, 0.10, 0.05 at 500 kn. The see-and-avoid concept has striking physical and behavioral limitations.

Summary Statistical agencies often release a masked or perturbed version of survey data to protect the confidentiality of respondents' information. Ideally, a perturbation procedure should provide confidentiality protection without much loss of data quality, so that the released data may practically be treated as original data for making inferences. One major objective is to control the risk of correctly identifying any respondent's records in released data, by matching the values of some identifying or key variables. For categorical key variables, we propose a new approach to measuring identification risk and setting strict disclosure control goals. The general idea is to ensure that the probability of correctly identifying any respondent or surveyed unit is at most ξ , which is pre‐specified. Then, we develop an unbiased post‐randomisation procedure that achieves this goal for ξ &gt;1/3. The procedure allows substantial control over possible changes to the original data, and the variance it induces is of a lower order of magnitude than sampling variance. We apply the procedure to a real data set, where it performs consistently with the theoretical results and quite importantly, shows very little data quality loss.

Transportation plays a central role in facilitating economic activities across sectors and between regions and is essential to business-cycle research. With four coincident indicators that represent different aspects of the transportation sector—an index of transportation output, payroll, personal consumption, and employment—the classical business-cycle and growth-cycle chronologies are defined for this sector. It is found that, relative to the economy, business cycles in the transportation sector have an average lead of nearly 6 months at peaks and an average lag of 2 months at troughs. Similar to its business cycles, growth slowdowns in the transportation sector also last longer than the economywide slowdowns by a few months. This study underscores the importance of transportation indicators in monitoring cyclical movements in the aggregate economy.

This article examines a cross-section of literature and other resources to reveal common reproducibility issues faced by stakeholders regardless of subject area or focus. We identify a variety of issues named as reproducibility barriers, the solutions to such barriers, and reflect on how researchers and information professionals can act to address the ‘reproducibility crisis.’ The finished products of this work include an annotated list of 122 published resources and a primer that identifies and defines key concepts from the resources that contribute to the crisis.

Young drivers have been identified as a group at high risk for fatigue-related accidents, particularly during the nighttime hours (Pack et al.). However, there is a probable relationship between nighttime fatigue-related accidents and the number of young drivers on the road during this same time period. This paper introduces a measure of exposure, the number of drivers on the road for a given hour, and evaluates its affect on fatal accident and fatigue-related fatal accident rates. Data from the National Household Travel Survey 2001 and the Fatality Analysis Reporting System are used. Overall, fatal accident and fatal fatigue-related accident rates are low but the increased risk of young drivers, particularly during the nighttime hours is highlighted.

Freight fluidity, defined here as travel time reliability or consistency, has important implications for many sectors of the national economy. Due to limited information, waterway fluidity has historically been difficult to measure. However, with time-stamped and geo-referenced vessel position reports now available through the U.S. Coast Guard Nationwide Automatic Identification System archives, it is possible to conduct detailed examinations of fluidity along most portions of the U.S. inland waterway system. This report presents case studies of waterway fluidity and seasonal trends for three heavily trafficked segments of the inland waterway system: the Upper Ohio River from the Port of Pittsburgh to the Ports of Cincinnati-Northern Kentucky (above the metropolitan Cincinnati, OH area), the Lower Mississippi River Main Stem from the Port of Metropolitan St. Louis to the Port of South Louisiana near New Orleans, LA, and the Gulf Intracoastal Waterway from the Port of Houston, TX, to the Port of South Louisiana near New Orleans, LA.

The focus of this initial study is on the role of distance and location in long-distance passenger travel and specifically how these affect mode choice. Distinguishing between short-and long-haul travel is one method for selecting a mode choice model structure. According to the literature, distances that define short-haul travel should exhibit competition among the modes, whereas long-haul travel distances will exhibit dominance of a single mode, generally air travel. In the literature, some values have been suggested [400 km (250 mi), 800 km (500 mi), 992 km (620 mi), etc.]. This study considers the mode shares for five states to determine ( a) if these values emerge to distinguish between competitive and noncompetitive mode share distance ranges and ( b) if competitive and noncompetitive mode share distance ranges are consistent across different states. The American Travel Survey (ATS), collected in 1995 by the Bureau of Transportation Statistics, is used.

Guide to Economic Indicators, 4th Edition. By NORMAN FRUMKIN. Armonk, NY, M. E. Sharpe & Co., 2005. 304 pp. $69.95, cloth; $27.95, paper.

The U.S. Department of Transportation currently is evaluating national transportation policy on the role the federal government should play to improve access to intercity public transportation services from smaller communities and rural areas. An important first step in this evaluation is to determine the size and location of underserved markets. This question is particularly well suited to the kind of spatial analysis that is possible through geographic information systems (GIS) technology. Presented are the results of a geospatial analysis to identify those places that do not have reasonable access to intercity public transportation services and the potential impact of that lack of access on the people living in those places. By using national level, geospatial databases of intercity public transportation access points and locations of places defined in the 1990 census, the analysis employed GIS to create buffers of specified distances around each access point to find those places located beyond the buffers. A total of 443 places with populations between 2,500 and 50,000 were found to lie beyond a reasonable access distance to any intercity public transportation service. Those places are located predominantly in the rural Midwest, Appalachia, and the Mississippi Delta and along the Texas-Oklahoma border.

This report aims to help policymakers and staff at all levels of government make transportation investments that serve the public better. Amazingly, we simply don’t know how effective government spending is at achieving the outcomes the public expects and has been promised! Clearly, taxpayer dollars buy roads, bus service, airports, ferry service, and other transportation facilities and services. But it is unclear how well such investments help get people where they want to go, create jobs, improve public health, support community development, and provide other benefits. In other words, it is uncertain how cost-effectively the means (transportation investments) achieve the ends (public benefits)—how much “bang for the buck” transportation investments provide. States, metropolitan planning organizations (MPOs) and local governments have opportunities to incorporate outcomes into all phases of transportation decision-making. This report recommends that governments make transportation investment decisions using a four-phase outcomes-based cycle: planning, governance & finance, programming, and reporting. In more detail, this report offers eight sets of recommendations.

Although deletion of cases is still a common method of dealing with item nonresponse, imputation is a major alternative. With traditional methods of imputation, though, the usual variance formulas understate the variance of estimates. This paper proposes that items be imputed from distributions more diffuse than those of the real data, thereby compensating for the underestimation of variance by the usual formulas. The impact on covariances is considered in the design of the method. The method is intended for use by data analysts applying techniques based on functions of first and second moments of means only.

Fifteen-passenger vans, which make up about 0.25 percent of the passenger vehicle fleet in the United States, are frequently used to transport school sports teams, van pools, church groups, and other groups. Although they are involved in a proportionate number of fatal accidents compared to their percentage in the fleet, they are involved in a higher number of single-vehicle accidents involving rollovers than are other passenger vehicles. The purpose of this paper is to identify the association of driver characteristics with van rollover. Results indicate that driver sex and driver-related factors (failure to keep in proper lane, driving too fast for conditions, and over correcting) are related to van rollover. Driver training and experience as well as technology have potential to prevent 15-passenger van rollover accidents.

This table shows the number and percent of people in the contiguous United States (excludes Alaska and Hawaii) potentially exposed to different levels of noise from passenger rail sources.

Veratox for Fumonisin, Chuck Bird

The COVID-19 pandemic initially caused a significant decrease in travel. Whereas highway travel rebounded quickly, transit use has not fully returned and may not fully return in the short or medium term. This report discusses the results from a survey of travelers' stated use of transit before, during, and after the pandemic, focusing on identifying factors associated with the change in transit use, including stress and fear of COVID-19. The study included data collection in three experiment phases. In the first phase of data collection, the survey was distributed via several online platforms while the data for the second phase of the experiment was collected at Texas A&M’s Human Behavior Laboratory (HBL). The third phase included a virtual reality (VR) experiment conducted at the University of Puerto Rico at Mayagüez that included skin conductance response measurements along with the survey questionnaire. The research found there may be as many as 35% to 45% of respondents who will not use transit as much in the future due to COVID-19. This higher range occurs if both the responses “Extremely” and “Very” are considered indicators of future travel decisions for survey questions asking the importance or likeliness of COVID-19 factors. However, if we consider only those respondents who indicated “Extremely Important,” “Extremely Likely,” and “Extremely Uncomfortable,” then a lower range of 15% to 25% of respondents will not use transit as much in the future. When examining Texas A&M students only, the percentage who may use less transit due to COVID-19 is likely smaller than 15%, but greater than 0%. Therefore, in addition to telecommuting and mode shifts caused by the pandemic, transit agencies must overcome the stresses and fears that commuters have related to COVID-19 for ridership to return to pre-pandemic levels.

This table shows the number and percent of people in the contiguous United States (excludes Alaska and Hawaii) potentially exposed to different levels of noise from passenger rail sources.

Produced by the Bureau of Transportation Statistics (BTS), this site is