Transport systems analysis : models and data

Funding: This research project has been funded by Spanish R+D Programs, specifcally under Grant PID2020-112967GB-C31.Rapid advancements in new technologies, especially information and communication technologies (ICT), have significantly increased the number of sensors that capture data, namely those embedded in mobile devices. This wealth of data has garnered particular interest in analyzing transport systems, with some researchers arguing that the data alone are sufficient enough to render transport models unnecessary. However, this paper takes a contrary position and holds that models and data are not mutually exclusive but rather depend upon each other. Transport models are built upon established families of optimization and simulation approaches, and their development aligns with the scientific principles of operations research, which involves acquiring knowledge to derive modeling hypotheses. We provide an overview of these modeling principles and their application to transport systems, presenting numerous models that vary according to study objectives and corresponding modeling hypotheses. The data required for building, calibrating, and validating selected models are discussed, along with examples of using data analytics techniques to collect and handle the data supplied by ICT applications. The paper concludes with some comments on current and future trends

Estimation/updating of origin-destination flows: recent trends and opportunities from trajectory data

Understanding the spatial and temporal dynamics of mobility demand is essential for many applications over the entire transport domain, from planning and policy assessment to operation, control, and management. Typically, mobility demand is represented by origin-destination (o-d) flows, each representing the number of trips from one traffic zone to another, for a certain trip purpose and mode of transport, in a given time interval (Cascetta, 2009, Ortuzar and Willumsen, 2011). O-d flows have been generally unobservable for decades, thus the problem of o-d matrix estimation is still one of the most challenging in transportation studies. In recent times, unprecedented tracing and tracking capabilities have become available. The pervasive penetration of sensing devices (smartphones, black boxes, smart cards, ...) adopting a variety of tracing technologies/methods (GPS, Bluetooth, ...) could make in many cases o-d flows now observable. The increasing availability of trajectory data sources has provided new opportunities to enhance observability of human mobility and travel patterns between origins and destinations, recently explored by researchers and practitioners, bringing innovation and new research directions on origin-destination (o-d) matrix estimation. The purpose of this thesis is to develop a deep understanding of the opportunities and the limitations of trajectory data to assess its potential for ameliorating the o-d flows estimation/updating problem and for conducting o-d related analysis. The proposed work involves both real trajectory data analysis and laboratory experiments based on synthetic data to investigate the implications of the trajectory data sample distinctive features (e.g. sample representativeness and bias) on demand flows accuracy. Final considerations and results might provide useful guidelines for researchers and practitioners dealing with various types of trajectory data sample and conducting o-d related applications

Commuting flows & local labour markets: Spatial interaction modelling of travel-to-work

One of the most promising approaches to mitigating land-use and transportation problems is continued research on urban commuting. Commuting is essential to many individuals, allowing them to participate in the labour market and earn a living to meet their essential needs. As such, a better understanding of the determinants of commuting will ultimately lead to a better understanding of the complexities of employment, housing, and the many spatial processes underlying commuting. However, in order to understand the commuting process, it is important to examine the milieu within which commuting takes place: the local labour market (LLM). In this thesis, the interplay between commuting and LLMs is explored through the use of regionalisation techniques and spatial interaction models. It is shown that LLM characteristics play a significant role in intra-regional commuting patterns and that a failure to account for LLM conditions may seriously hinder the applicability of models of commuting. Specically, it is found that there are many dierent LLMs across Ireland, and that these LLMs characterise the commuting patterns of population sub-groups. By incorporating these LLMs into models of commuting, this thesis shows that in addition to distance and working population size, the spatial structure of origins and destinations and a number of non-spatial attributes such as unemployment, housing density, and education, all signi- cantly aect commuting ows. Furthermore, the distance decay component of these models appears to be capturing a combination of geographical distance and regional dierentiation due to LLM boundaries, leading to `functional' distance decay. This concept of functional distance decay is a key nding of this thesis, and indicates that in addition to the conguration of origins and destinations, distance decay is also dependent on the spatial structure of LLMs, or more generally, the totality of surrounding conditions within which spatial interaction takes place

Forecasting dispersal of nonindigenous species

A leading conceptual model of the invasion process suggests that nonindigenous species (NIS) must pass through a series of ‘filters’ when dispersing from colonized to non-colonized regions. These steps include the initial dispersal of propagules, survival of these propagules upon encountering the new physicochemical environment, and biological integration into the new community. Here, I forecast invasions for two aquatic NIS, the spiny waterflea Bythotrephes longimanus and zebra mussel Dreissena polymorpha based on the entire invasion sequence using gravity models to assess movement of propagules, data on lake morphometry and physicochemistry, and data on fish community composition. The gravity models included information on movement patterns of recreationalists and life-history characteristics of the NIS that may facilitate invasions. I also contrast the abilities of a hierarchical approach to a single ‘all-in-one’ model that considered all variables simultaneously in detecting actual invasions versus false alarms. Here, the ‘all-in-one’ model was better at predicting invasions if they had, in fact, occurred. Next, I compare predictions of Bythotrephes invasions for three types of gravity models: total-flow-, production- and doubly-constrained. These models differ in the type of information required to parameterize the model. The Production-constrained model was most likely to detect actual invasions relative to false alarms, and the total-flow-constrained model was least likely to predict false positives. I also compare backcast patterns of propagule pressure for two groups of related species: one group comprising the spiny waterflea and the fishhook waterflea Cercopagis pengoi; and the other, the zebra mussel and quagga mussel Dreissena rostriformis bugensis. Differences in species\u27 life-histories may interact with various transport mechanisms to produce highly dissimilar levels of propagule pressure to inland lakes. Species with the broadest distribution had the highest propagule pressure scores. Finally, I examine the attributes of an invasion network formed by lakes invaded by spiny waterfleas connected by recreational traffic. I was interested in whether specific lakes served as ‘hubs’, and whether the network of lakes exhibited a scale-free topology. Management implications for a scale-free invasion network include a potential decrease in the overall rate of NIS spread if propagule flow from ‘hubs’ is reduced

Application of a subnetwork characterization methodology for dynamic traffic assignment

textThe focus of this dissertation is a methodology to select an appropriate subnetwork from a large urban transportation network that experiences changes to a small fraction of the whole network. Subnetwork selection techniques are most effective when using a regional dynamic traffic assignment model. The level of detail included in the regional model relieves the user of manually coding subnetwork components because they can be extracted from the full model. This method will reduce the resources necessary for an agency to complete an analysis through time and cost savings. Dynamic traffic assignment also has the powerful capability of determining rerouting due to network changes. However, the major limitation of these new dynamic models is the computational demand of the algorithms, which inhibit use of full regional models for comparing multiple scenarios. By examining a smaller window of the network, where impacts are expected to occur, the burden of computer power and time can be overcome. These methods will contribute to the accuracy of dynamic transportation systems analysis, increase the tractability of these advanced traffic models, and help implement new modeling techniques previously limited by network size. The following describes how to best understand the effects of reducing a network to a subarea and how this technique may be implemented in practice.Civil, Architectural, and Environmental Engineerin

A Study on the Access of Ministry, Government Agencies, and Law Enforcement Authority to Electronic System Organizers’ Data and Systems

Access to data and systems of Electronic System Organizers (ESOs) is a sensitive issue because it is considered a means of coercion (dwang middelen) that might infringe personal data protection, freedom of speech, individual privacy that also related to intellectual property rights and trade secrets. In light of this, further in-depth analysis is needed to assess whether The Indonesian Ministry of Communication and Informatics (MOCI) Regulation No. 5/2020 on Electronic System Organizers (ESOs) has accommodated various key elements to safeguard the general principles of human rights, intellectual property rights, and personal data protection. This paper concludes that access to ESO’s system might not be the best practice and should be taken as a last resort after all mitigation actions on information security have been carried out.