The future for in‐vehicle information systems: The technology and its impacts

In‐vehicle information has an important social role to play in improving the efficiency and safety of travel by all modes. In this review, three generations of system are identified. The first generation consists of simple in‐vehicle units relying heavily on external data. The second generation has more sophisticated in‐vehicle units with colour TFT screens and DVD players for maps and entertainment. The third generation again makes use of external data, using the mobile phone network to download map sections and other data as and when required, thereby obviating the need for beacons and map CDs. For locationing, GPS (and/or Galileo, the European version of GPS) remains the favoured technology. Portable devices offering multi‐modal information could improve inter‐modal transport efficiency.     

Hedonic modeling of commercial property values: distance decay from the links and nodes of rail and highway infrastructure

Transportation - This study investigates the impacts of positive and negative externalities of highways and light rail on commercial property values in Phoenix, Arizona. We hypothesize that the...     

Why new technologies cannot radically improve the quality of urban transportation

In recent years a great deal of time and effort has been expended on the development of new modes of transport for cities. It is argued in this paper that this work is unlikely to be very productive because the major remaining flaw in the provision of transportation services—the inability of one mode to provide a good service to concentrated and dispersed trip ends—seems unavoidable. To make the required breakthrough a new mode must be frugal in its demands for space, flexible in its operation and fast. But an analysis of the performance of existing and prototype modes suggest that there is a fundamental technological barrier that precludes any one mode from performing well in more than two out of these three ways. This implies that any further improvements in travel for the urbanite must be made through existing modes and their derivatives and will be quite limited. It also suggests that the only possible way of substantially improving urban transportation is to build or rebuild towns so that one of the important mode attributes mentioned above is rendered superfluous.     

Personal travel management: the adoption and consideration of travel‐related strategies

Traveler behavior plays a role in the effectiveness of travel demand management (TDM) policies. Personal travel management is explored in this paper by analyzing individuals' adoption and consideration of 17 travel‐related alternatives in relation to socio‐demographic, mobility, travel‐related attitude, personality and lifestyle preference variables. The sample comprises 1282 commuters living in urban and suburban neighborhoods of the San Francisco Bay Area. Among the findings: females were more likely to have adopted/considered the more ‘costly’ strategies; those with higher mobility were more likely to have adopted/considered travel‐maintaining as well as travel‐reducing strategies; and those who like travel and want to do more are less likely to consider travel‐reducing strategies. These findings, when combined with those of earlier work on this subject, present a compelling argument for the need to further understand traveler behavior – particularly in response to congestion and TDM policies.     

The optimal dispatching of taxis under congestion: A rolling horizon approach

Taxis make an important contribution to transport in many parts of the world, offering demand‐responsive, door‐to‐door transport. In larger cities, taxis may be hailed on‐street or taken from taxi ranks. Elsewhere, taxis are usually ordered by phone. The objective of a taxi dispatcher is to maximize the efficiency of fleet utilization. While the spatial and temporal distribution of taxi requests has in general a high degree of predictability, real time traffic congestion information can be collected and disseminated to taxis by communication technologies. The efficiency of taxi dispatching may be significantly improved through the anticipation of future requests and traffic conditions. A rolling horizon approach to the optimisation of taxi dispatching is formulated, which takes the stochastic and dynamic nature of the problem into account. Numerical experiments are presented to illustrate the performances of the heuristics, taking the time dependency of travel times and passenger arrivals into account.     

Working at home and elsewhere: daily work location,telework, and travel among United States knowledge workers

Transportation - The mediation of work practices by information and communication technologies enables knowledge workers to telework from remote non-office locations such as their homes, or to work...     

An ensemble approach for conflict detection in Free Flight by data mining

Airborne separation assurance is a key requirement for Free Flight operations. A variety of conflict detection (CD) and resolution algorithms have been developed for this task. A lack of rigorous evaluation and the existence of an infinite number of possible conflict geometries in Free Flight makes the choice of which algorithm to be placed in the cockpit a challenging task for the designers of future air traffic management (ATM) systems. In this paper, we propose an ensemble approach for CD in Free Flight. The ensemble consists of several CD algorithms, a rule set for each algorithm describing its learned behavior from its past performance and a switch mechanism to choose an appropriate CD algorithm given probe characteristics. A novel mechanism to evolve complex conflict scenarios, using genetic algorithms (GA), is developed and integrated in a fast time air traffic simulator to generate the performance data of CD algorithms. Data mining techniques are then employed to identify implicit patterns in the probe characteristics where the CD algorithms missed or falsely identified a conflict. These patterns are formulated as rule sets for each CD algorithm and are then used by a switch in the ensemble to route a probe for conflict prediction. Given probe characteristics, the CD algorithm, which is less likely to miss or falsely identify a conflict, is selected to evaluate the probe for potential conflict. The performance of the ensemble and of individual algorithms is evaluated by comparing the Pareto efficient set of solutions generated by them. The ensemble approach demonstrates a significant reduction in the number of missed detects and false alarms as compared to individual algorithms. The proposed methodology is capable of accommodating existing as well as new CD models and can be extended to other ATM concepts as well.