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The discrete choice analysis of residential location choice forms an important part of land use-transport modelling systems but gives rise to a number of significant modelling challenges, one of which is the choice set formation problem. A number of alternative approaches exist to addressing the choice set formation problem, but to the best of our knowledge, there have been no efforts to empirically compare their performance using real choice data. In this paper, we propose to address this gap by examining the performance of several choice set formation methods within the context of residential location choice in London. The paper presents a brief review of the relevant theoretical and empirical literature on the treatment of the choice set formation problem in the context of spatial choice and sets out the characteristics of the specific modelling approaches implemented in the empirical research. In particular, we compare a recently proposed hazard-based screening model with more conventional pure statistical treatments. The empirical research uses a specially constructed data-set on residential location choice, developed by the authors for the Greater London area, which draws on information from a number of separate data sources (including revealed preference data from the London Area Travel Survey). The alternative choice set formation approaches are assessed in terms of their prediction performance on a hold-out validation sub-sample and also in terms of estimated model parameters. [ABSTRACT FROM PUBLISHER]

Vehicular Ad-Hoc Networks (VANETs) attract considerable research and commercial interest with promising applications in a number of areas including cooperative vehicle-highways systems, sensor networks, and safety systems. However, as a result of high speed and variable driver behavior, automotive ad-hoc networks behave in fundamentally different ways to the most prevalent models in Mobile Ad-Hoc Network (MANET) research. Previous work in MANETs has mostly assumed that the mobile nodes move randomly with an unconstrained mobility model, and it is clear that a random mobility model is not adequate to represent the major characteristics of real-world vehicle motions and may therefore lead to unreliable results. Recent studies of VANETs have attempted to introduce macro- and micromobility constraints to model vehicle motions, but they have mostly focused on modeling the mobility of generic private vehicles. Given the potential for the coordinated deployment of network nodes on centrally managed fleet vehicles, it has become important to model the characteristics of a VANET featuring vehicles of different types, with systematically different behavior patterns. In this article, the authors study the connectivity of mobile ad-hoc networks that consist of buses moving in urban area and examine the implications for transport-related services. Buses have a unique set of behavior characteristics (e.g., fixed routes, schedules, bus stops, specific priorities), which gives rise to distinct effect on node connectivity in the communication network. Through extensive simulations on the basis of real bus routes in central London, the authors (a) demonstrated the effect of the locations of stops and the prevailing traffic patterns on node connectivity (including the distributions of contact duration and intercontact time between buses) and (b) explored its implication on the design of a dissemination system to capture and disseminate data. Their results give a key message that the mobility of buses has to be modeled explicitly, and such kind of knowledge of connectivity among buses will be significant for the studies of routing algorithms and other networking functions in interbus communication networks. [ABSTRACT FROM AUTHOR]