Transportation System Users Research Articles

Complexity analysis of the Next Gen Air Traffic Management System: trajectory based operations

According to Federal Aviation Administration traffic predictions currently our Air Traffic Management (ATM) system is operating at 150 percent capacity; forecasting that within the next two decades, the traffic with increase to a staggering 250 percent [17]. This will require a major redesign of our system. Today's ATM system is complex. It is designed to safely, economically, and efficiently provide air traffic services through the cost-effective provision of facilities and seamless services in collaboration with multiple agents however, contrary the vision, the system is loosely integrated and is suffering tremendously from antiquated equipment and saturated airways. The new Next Generation (Next Gen) ATM system is designed to transform the current system into an agile, robust and responsive set of operations that are designed to safely manage the growing needs of the projected increasingly complex, diverse set of air transportation system users and massive projected worldwide traffic rates. This new revolutionary technology-centric system is dynamically complex and is much more sophisticated than it's soon to be predecessor. ATM system failures could yield large scale catastrophic consequences as it is a safety critical system. This work will attempt to describe complexity and the complex nature of the NextGen ATM system and Trajectory Based Operational. Complex human factors interactions within Next Gen will be analyzed using a proposed dual experimental approach designed to identify hazards, gaps and elicit emergent hazards that would not be visible if conducted in isolation. Suggestions will be made along with a proposal for future human factors research in the TBO safety critical Next Gen environment.

Varieties of Transportation Justice: US Transportation Equity Policy and the Civil Rights Movement

Transportation policy has long been concerned with achieving direct outcomes such as maximum mobility, reduced unit travel times and increased access, and indirect outcomes such as regional economic development. More recently a distinct concern has arisen regarding equity and justice in transportation, in a very broad sense a concern about whether all transport system users have equal access and fair burden and benefit distributions. The equity policy framework in the US rests upon and is closely bound up with the post Civil War struggle for civil rights. This article describes what American conceptions of civil rights have come to mean in US policy and legal spheres; discusses the extent to which transportation is seen as a civil right; discusses what the limits of those rights are and how those definitions have changed over time; and suggests some current issues for US policymakers that a civil rights approach to transportation equity must consider going forward.

Economy of information in congested transport systems

Emerging communication and information technologies increasingly enable users of transport systems to determine their own whereabouts and help support their trip scheduling and rescheduling decisions by providing timely information on traffic conditions. The authors investigate the linkages between behavioural attitudes of users towards risk and valuation of information, by utilising decision-theoretic and risk management principles and extensive-form game trees. Several examples are provided to demonstrate the increase in expected value and steps that should be encountered in the provision of travel information, with particular emphasis on multi-modal transport systems with congestion effects.

Communicatively accessible public transport for people with aphasia: A pilot study

Background: There has been little research as to how society accommodates the communicative needs of people with aphasia. The accessibility of public transport becomes important post stroke and good communication skills are vital for successful travel. Aims: This pilot study aims to identify the communicative barriers and facilitators that exist when people with aphasia use public transport. Methods & Procedures: The qualitative study used in‐depth, semi‐structured interviews and observations with seven participants who presented with mild‐moderate aphasia. Interviews were conducted pre‐ and post‐journey. Observations were conducted throughout the journey chain, from planning the trip to arrival at destination. Outcomes & Results: The most significant barriers to a public transport journey were within the category of Public Transport Services and Systems, most notably during transactions requiring verbal expression and where time constraints were at a premium. The most common facilitators were in the categories of Products and Technology for Communication (e.g., written materials) and Support from Other People. Conclusion: These findings suggest that the majority of communicative barriers for commuters with aphasia occur in circumstances when verbal communication is mandatory, or when rapid information processing is required. Additionally, people with aphasia employ many communicative facilitators. These have enabled them to travel successfully and need to be promoted to new users of public transport systems. This study highlights the need to address communicative aspects of accessibility within public transport systems.

Automated decision procedure for earthquake early warning

Early warning systems represent an effective tool for disseminating timely information about potentially catastrophic hazards to the public, emergency managers, and operators and users of transportation systems, industrial facilities, public buildings including schools and government offices, and private residences. This information gives the possibility of taking action to initiate mitigation or security measures before a catastrophic event occurs. Earthquake early warning technologies represent a promising application, especially in areas where faults are located in the proximity of an urbanized area, such as in Los Angeles and San Francisco, California. For earthquake early warning systems, automated procedures for taking action are necessary due to the short lead time available, including an automated decision procedure to decide when to activate mitigation or security measures based on the expected consequences of taking, or not taking, such actions. In this work, a decision procedure is presented that accounts for the uncertainty in the predicted ground shaking intensity at a site of a facility by deciding whether or not to take a mitigation action based on the probabilities of false and missed alarms. It uses a cost-benefit analysis of the consequences of making a wrong decision. It is shown how the method may be extended to other predictors, such as expected losses, that may be more effective parameters for rational decision making from the perspective of facility stakeholders.

Tranportation System in Cartagena: the Behavior of Public Urban Transportation System Users

This document analizes the preferences of public transportation system users in Cartagena de Indias - Colombia. The research uses related variables on transportation modes chosen by people and some other characteristics of the people who make such decisions. The analysis allows us to understand the behavior of public urban transportation system users in the city of Cartagena, and shows us evidence about some probable reasons associated with new informal public transportation modes, which at this moment play an important role in the public transportation market in the city. The research uses binary choice probabilistic models (Probit) and primary information collected by a survey for system users.

Experimental tour-based travel demand models

In this paper some experimental sequential models for the simulation of trip-chains are presented; the models have been calibrated on the basis of a survey made in a medium-sized town. This work is part of a research, effected by the Department of Regional Planning of the University of Calabria, to forecast travel demand and to analyze travel behavior of the transport system users (Festa et al., 2000). The travel choices of individuals have been reproduced simulating the decisional process in sequential steps, by models based on the random utility theory. The tour generation models, proposed by Festa et al. (2001), have been once again calibrated introducing a new set of variables in the systematic utility function of the alternatives of choice. Some models for the travel type choice simulation are also presented; the models have a Binomial Logit functional structure, with trip-tour and trip-chain as choice alternatives.

Introducing environmental equity dimensions into the sustainable transport discourse: issues and pitfalls

Environmental equity considerations should be an essential ingredient of any sustainable transport strategy. Yet, it is unclear how environmental equity considerations can be incorporated into the sustainable transport discourse in a meaningful manner. The paper explores the multiple facets of the meaning of environmental equity in the case of transport. Then, the issues that need to be addressed in any analysis of each facet are delineated. On this basis it is suggested that the conventional environmental equity analysis, whereby the affected areas are compared to unaffected areas, is unlikely to render robust or meaningful results. Rather, the focus of research should be on the equity implications of policies geared to mitigate transport systems' environmental externalities, and on comparisons of users of the different transportation systems to those exposed to the negative environmental externalities of these systems. The results of such studies could provide direct inputs into comprehensive balanced policy packages within a sustainable transport strategy.

Dynamic equilibria in transport systems

In the transportation science the attention has been for some time concentrating on the issue of an appropriate way of introducing the dynamics into the models of equilibria of flows in transport systems. They have been one of the main modeling techniques of transportation planning in the recent decades. Most of the equilibrium notions in use are basically static by nature, which leads to severe problems in approaching the dynamics of the equilibrium behaviour of transport systems. Probably the most important equilibrium notion of this type has been the First Wardrop Equilibrium Principle. Our paper discusses one of the possible mathematical approaches of introducing the dynamics into the underlying network equilibrium model of this notion in a way that would make it possible to analyse the impact of the distribution of the information on the equilibrium behaviour of the users of transport systems. Two such dynamic notions of flow equilibria are introduced. We analyse some of their existence and algorithmic properties, and their implications for the equilibrium dynamics of transport systems.

The role of accident exposure in transport system safety evaluations I: Intersection and link site exposure

AbstractRealistic predictions of the likely safety performance of advanced transport systems will need to draw on the knowledge accumulated from a large number of safety evaluations which have already been undertaken for existing transport systems. In particular, safety evaluations of future technologies must avoid the methodological pitfalls experienced in extensively researched areas, such as road safety, if such evaluations are to be meaningful. This paper reviews the use of exposure for a broad range of road safety studies, and concludes that unsatisfactory treatment of exposure is a common failing in past evaluations of the effectiveness of road accident countermeasures. Whilst a broad range of safety analyses is discussed, the use of exposure in site safety studies is emphasized. A follow‐up paper will extend the discussion to other aspects of accident exposure including exposure measures for large groups of transport system users.