https://hdl.handle.net/2123/19751 Sat, 13 Jun 2026 15:10:03 GMT 2026-06-13T15:10:03Z https://hdl.handle.net/2123/21371 A commodity-based production and distribution freight model with application to Sydney, New South Wales Teye, Collins; Hensher, David A. The complexity of freight demand forecasting coupled with non-availability of data with the required scale and features often limits its inclusion in demand forecasting. To model freight demand, data are required on various aspects of the freight system including and not limited to commodities, shipments, demand and production cycles, the actors, and how they interact on the supply and logistics corridors and the broad economic influences on freight movements. Available data on many of these aspects of freight, at varying degrees of aggregation spatially, are publicly available for modelling in Australia. However, these data have not been fully utilised to build a freight model suitable for explaining freight movements and their impacts on the local economy. This is largely due to the diverse nature of these datasets, especially relating to the degree of aggregation and the inherent difficulty of combining these datasets in a consistent and unbiased way. This paper provides a novel approach based on the principle of entropy maximisation to combine these diverse datasets to develop a freight behavioural logit model for the state of New South Wales (NSW), Australia. The resulting model is a linked logit model system comprising a Commodity Production Model (CPM), and Commodity Distribution Model (CDM), segmented by commodity type and vehicle class. The focus is on commodity flows and not conversion to vehicle flows. An important outcome is the link between maximising entropy and maximising access to each commodity group by each vehicle class over production and consumption zones. The implementation of the model in practice and the illustration of its key features are presented using NSW as case study. Sun, 01 Dec 2019 00:00:00 GMT https://hdl.handle.net/2123/21371 2019-12-01T00:00:00Z https://hdl.handle.net/2123/21283 Resurgence of Demand Responsive Transit services – Insights from BRIDJ trials in Inner West of Sydney, Australia Perera, Supun; Ho, Chinh; Hensher, David This paper outlines the key insights gained from the Demand Responsive Transit (DRT) operations in Inner West Sydney, since its commencement in July 2018. It was identified that DRT can play a number of roles to complement the general public transport network, including the (1) peak feeder function, (2) connection function, and (3) coverage function. As a result, if successfully integrated with the existing public transport network, DRT can unlock broader fixed route network enhancements through resource reallocation to the key trunk routes. While the patronage for DRT services was found to steadily increase since the commencement of the operations, the key barrier for these services to attract further regular patronage remains the relatively higher fares arising due to the lack of Opal benefits such as mode transfer discounts or weekly caps. Therefore, while DRT has great potential to link those in less connected areas with public transport hubs, thus facilitating a modal shift away from private vehicles, they need to be affordable and well regulated. In the near future, DRT services will likely be integrated into MaaS applications, which could provide immense benefits in terms of sustainable travel and the effective utilisation of road network capacity. Fri, 01 Nov 2019 00:00:00 GMT https://hdl.handle.net/2123/21283 2019-11-01T00:00:00Z https://hdl.handle.net/2123/21282 Overview of Australian Urban Road Tunnels Ridley, Peter This paper collates data (location, size, cost of construction, maintenance and operation) on long Australian urban road tunnels exceeding 1 km in length with opening dates up to 2020. An understanding of traffic behaviour, demand and toll revenue leads to estimations of return on investment and costs. Operating constraints and parameters; traffic flow, pollution and energy consumption are used to evaluate the performance of the tunnels along with their safety (accidents and fire) record. Fri, 01 Nov 2019 00:00:00 GMT https://hdl.handle.net/2123/21282 2019-11-01T00:00:00Z https://hdl.handle.net/2123/21223 Cycling in Australia and Japan: some preliminary perspectives Greaves, Stephen; Tempia, Juliette; Yamamoto, Toshiyuki This brief paper contributes to ongoing dialogue around arresting the stagnation and in some cases decline in cycling in Australian cities by looking to Japan, a nation that has achieved comparatively high levels of cycling without large-scale infrastructure investments. We review the historical evolution of cycling in both nations, considering the role of the bicycle in both societies, trends in ownership and usage, other transport modes, cycling environment, safety trends, and rules and regulations. The paper is the initial part of an ongoing collaboration around cycling policies between the University of Sydney and Nagoya University. Tue, 01 Oct 2019 00:00:00 GMT https://hdl.handle.net/2123/21223 2019-10-01T00:00:00Z https://hdl.handle.net/2123/21221 Passive value capture through income taxation, and a beneficiaries-based funding model for infrastructure Bushell, James Value capture is used to describe a range of mechanisms used to fund infrastructure projects. Active value capture mechanisms, specifically designed to raise revenue are well documented including land taxes, asset sales and other mechanisms with a direct nexus to the infrastructure that it funds. However passive value capture mechanisms exist, through extant government tax systems that capture value without being part of a specific program or policy to pay for infrastructure. These and their potential role in infrastructure investment are not well documented, with increased income tax collection representing a potentially significant stream of value capture funding for infrastructure investment. Through analysing current business cases with business beneficiaries, this paper documents income tax value capture and demonstrates how it may play a role in project funding. A beneficiary funding framework is developed to show how government investment levels may be structured to allow economically but non-financially viable projects to proceed to create value within the bounds of treasury constraints. Tue, 01 Oct 2019 00:00:00 GMT https://hdl.handle.net/2123/21221 2019-10-01T00:00:00Z https://hdl.handle.net/2123/21119 Are respondents aware of the process strategies used in decision-making? Modelling business location decisions using multiple stated process strategies Balbontin, Camila; Hensher, David A. Discrete choice studies are increasingly used in urban planning to understand preferences and to make informed decisions based on its outcomes. Traditional discrete choice modelling approaches have evolved in a setting in which some very specific behavioural assumptions are made in specifying decision-making. These assumptions have given rise to the study of alternative process strategies in decision-making, such as majority of confirming dimensions (MCD), attribute non-attendance (ANA), or value learning (VL). In this paper, a stated choice experiment was designed to understand business location decisions, where a location specialist had to compare their current location with two alternative locations. After each choice task, respondents were asked whether they used ANA in processing the choice tasks, and at the end of the experiment a number of questions were asked to identify whether specific process heuristics were used such as MCD and VL. Choice models were estimated to compare the influence of including different stated heuristics responses. The results show that the model which included the stated heuristics responses is superior in terms of the goodness of fit and in the estimates’ significance levels. The willingness to pay estimates derived from a traditional model were statistically equivalent to the ones derived from the stated multiple heuristics model. However, the median WTP derived from the stated multiple heuristics model was slightly higher and the confidence intervals lower than in the traditional model. Sun, 01 Sep 2019 00:00:00 GMT https://hdl.handle.net/2123/21119 2019-09-01T00:00:00Z https://hdl.handle.net/2123/21120 Capacity Alignment Planning for a Coal Chain: A Case Study Eskandarzadeh, Saman; Kalinowski, Thomas; Waterer, Hamish We study a capacity alignment planning problem for a coal chain. Given a set of train operators, a set of train paths, and a terminal comprising of a dump station and a set of routes from the dump station to the stockyard, we seek a feasible assignment of train operators to train paths, to time slots at the dump station, and to routes. The assignment must maximize the number of system paths in the resulting schedule and the schedule should perform well with respect to various performance criteria. We model the problem as a mixed-integer conic programme (MICP) with multiple objectives which we solve using a hierarchical optimization procedure. In each stage of this procedure we solve a single objective MICP. Depending upon whether we evaluate the associated performance criteria under a 2-or 1-norm we reformulate the MICP as either a mixed-integer second-order cone programme or as a mixed-integer linear programme respectively, and can streamline the hierarchical optimization procedure by exploiting properties of the model or observed behaviour on practical instances. We compare the performance of the procedure under the different norms on a real instance of the problem and find that the quality of the solutions found by the faster 1-norm procedure compare well to the solution found under the 2-norm. Sun, 01 Sep 2019 00:00:00 GMT https://hdl.handle.net/2123/21120 2019-09-01T00:00:00Z https://hdl.handle.net/2123/20922 Panic, irrationality, herding: Three ambiguous terms in crowd dynamics research Haghani, Milad; Cristiani, Emiliano; Bode, Nikolai; Boltes, Maik; Corbetta, Alessandro Background: The three terms “panic”, “irrationality” and “herding” are ubiquitous in the crowd dynamics literature and have a strong influence on both modelling and management practices. The terms are also commonly shared between the scientific and non-scientific domains. The pervasiveness of the use of these terms is to the point where their underlying assumptions have often been treated as common knowledge by both experts and lay persons. Yet, at the same time, the literature on crowd dynamics presents ample debate, contradiction and inconsistency on these topics. Method: This review is the first to systematically revisit these three terms in a unified study to highlight the scope of this debate. We extracted from peer-reviewed journal articles direct quotes that offer a definition, conceptualisation or supporting/contradicting evidence on these terms and/or their underlying theories. To further examine the suitability of the term herding, a secondary and more detailed analysis is also conducted on studies that have specifically investigated this phenomenon in empirical settings. Results. The review shows that (i) there is no consensus on the definition for the terms panic and irrationality; and that (ii) the literature is highly divided along discipline lines on how accurate these theories/terminologies are for describing human escape behaviour. The review reveals a complete division and disconnection between studies published by social scientists and those from the physical science domain; also, between studies whose main focus is on numerical simulation versus those with empirical focus. (iii) Despite the ambiguity of the definitions and the missing consensus in the literature, these terms are still increasingly and persistently mentioned in crowd evacuation studies. (iv) Different to panic and irrationality, there is relative consistency in definitions of the term herding, with the term usually being associated with ‘(blind) imitation’. However, based on the findings of empirical studies, we argue why, despite the relative consistency in meaning, (v) the term herding itself lacks adequate nuance and accuracy for describing the role of ‘social influence’ in escape behaviour. Our conclusions also emphasise the importance of distinguishing between the social influence on various aspects of evacuation behaviour and avoiding generalisation across various behavioural layers. Conclusions. We argue that the use of these three terms in the scientific literature does not contribute constructively to extending the knowledge or to improving the modelling capabilities in the field of crowd dynamics. This is largely due to the ambiguity of these terms, the overly simplistic nature of their assumptions, or the fact that the theories they represent are not readily verifiable. Recommendations: We suggest that it would be beneficial for advancing this research field that the phenomena related to these three terms are clearly defined by more tangible and quantifiable terms and be formulated as verifiable hypotheses, so they can be operationalised for empirical testing. Thu, 01 Aug 2019 00:00:00 GMT https://hdl.handle.net/2123/20922 2019-08-01T00:00:00Z https://hdl.handle.net/2123/20921 Review of bus rapid transit and branded bus service performance in Australia: From workhorse to thoroughbred Hensher, David A.; Wong, Yale Z; Ho, Loan Bus rapid transit on dedicated right-of-way and branded bus services with a distinct visual identity have been implemented in various forms around Australia over the past three decades. A major public policy debate has surrounded the relative success of these bus priority and branding measures as compared with generic route services in attracting patronage. In this paper, we devise a metric known as a (gross) performance ratio to quantify the success for each of 7 bus rapid transit systems and 20 branded bus services as compared with regular route buses across six Australian capitals. A regression analysis is conducted to determine the statistical significance of various bus priority and brand identity initiatives which are used as inputs into a normalisation procedure to determine the net performance ratio of each service offering. This allows an informed comparison between systems and cities, controlling for operating environment and other service characteristics. The results reinforce the merits of upgraded bus services both as standalone initiatives and also as an alternative to expensive, rail-based infrastructure investment. Measures like network legibility and brand identity all help upgrade the image of the bus from workhorse to thoroughbred. Thu, 01 Aug 2019 00:00:00 GMT https://hdl.handle.net/2123/20921 2019-08-01T00:00:00Z https://hdl.handle.net/2123/20730 Experience as a conditioning effect on choice – Does it matter whether it is exogenous or endogenous? Hensher, David A.; Balbontin, Camila; Greene, William H. Hensher and Ho (2017) proposed a way to condition the utility of each alternative in a choice set on experience with the alternatives accumulated over previous periods. The paper found that the overall statistical performance of the mixed logit model improved significantly, suggesting that this conditioning idea has merit. Experience was treated as an exogenous influence linked to the scale of the random component, and to that extent it captures some amount of the heterogeneity in unobserved effects, purging them of potential endogeneity. The current paper continues to investigate the matter of endogeneity versus exogeneity. The proposed approach implements the control function method in the representative component of the relative utility expressions in a choice model. These methods have been investigated by Wooldridge (2005), Train and Petrin (2010), Train and Wilson (2009) and Guevara and Hess (2019), amongst other authors. We develop two choice models, both using stated preference data. The paper extends the received contribution in that we allow for the endogenous variable to have an impact on the attributes through a two stage method, called the Multiple Indicator Solution, also implemented in a different context by Guevara et al. (2019) for a single (crowding) attribute, in which stage two is the popular control function method. In the first stage, the entire utility expression associated with all observed attributes is conditioned on the prior experience with an alternative. Hence, we are capturing possible correlates associated with each and every attribute and not just one selected attribute. We find evidence of potential endogeneity. The purging exercise however, results in both statistical similarities and differences in time and cost choice elasticities and mean estimates of the value of travel time savings. We are able to identify a very practical method to allow for possible endogeneity under heteroscedastic conditioning that will encourage researchers and practitioners to use such an approach in more advanced non-linear discrete choice models as a matter of routine. Mon, 01 Jul 2019 00:00:00 GMT https://hdl.handle.net/2123/20730 2019-07-01T00:00:00Z https://hdl.handle.net/2123/20729 Socioeconomic Differences in Ambiguity Attitudes, Partial Ambiguity and A-insensitivity: Evidence from Real-World Decision Making under Uncertainty Li, Zheng; Hensher, David A. Using a nonlinear mixed logit model, this study investigates commuter choice behaviour in the presence of uncertain travel time. Within the proposed source-dependent extended expected utility framework, the uncertainty-risk gap is captured in the source function and the attitude towards ambiguity is measured over the full subjective probability distribution. Based on one revealed preference dataset, we structurally estimated observed heterogeneity in ambiguity attitudes in terms of socioeconomic covariates and unobserved between-subject heterogeneity in taste preferences, while controlling for risk attitude and allowing for the trade-off between attributes. In addition to revealed age and gender differences in ambiguity preferences, other important findings include partial ambiguity seeking in this type of loss domain and the existence of likelihood insensitivity under uncertainty (i.e., a-insensitivity). This systematic investigation of decision making under uncertainty in real-market settings would offer behaviourally realistic inputs into the evaluation of social effects and design of effective policies. Mon, 01 Jul 2019 00:00:00 GMT https://hdl.handle.net/2123/20729 2019-07-01T00:00:00Z https://hdl.handle.net/2123/20644 Vertical Integration and its Implications to Port Expansion Zhu, Shengda; Zheng, Shiyuan; Ge, Ying-En; Fu, Xiaowen; Sampaio, Breno; Jiang, Changmin Over the years many shipping lines have established terminal operation companies, with some set up as independent firms. However, port authorities and local governments have not always welcomed external investment and control with open arms. The economic implications and each stakeholder’s best strategies remain unclear. This study develops an analytical model in order to study the effects of vertical integration, with a focus on shipping lines’ investment in ports’ capacity. Modelling results suggest that vertical integration between terminal operator and a shipping line leads to higher port capacity, port charge, market output and consumer surplus. It also reduces delay costs. All these results suggest that vertical integration can be an important source of synergy for the maritime industry. Although vertical integration increases the participating carrier’s output at the expenses of non-integrating rival shipping firms, the overall social welfare is still improved, which is indicated through the numerical analysis. Therefore, port authorities and government regulators should carefully review the market competition status as well as port expansion plans. Sat, 01 Jun 2019 00:00:00 GMT https://hdl.handle.net/2123/20644 2019-06-01T00:00:00Z https://hdl.handle.net/2123/20487 The Wider Economic Benefits of Transport Infrastructure: A Review Abelson, Peter The standard evaluation of transport infrastructure focuses on transport user benefits. Wider economic benefits (WEBs) are claims for additional economic benefits over and above user benefits. This paper reviews five main forms of WEB: agglomeration economies, the value of additional output in imperfectly competitive markets, labour supply effects, induced commercial and residential developments and overall impacts of transport investment on economies. The paper finds that the wider economic benefits in each case are generally likely to be small or non-existent. Where a claim for a substantial WEB is made, it needs to be supported by a reasoned narrative. Sat, 01 Jun 2019 00:00:00 GMT https://hdl.handle.net/2123/20487 2019-06-01T00:00:00Z https://hdl.handle.net/2123/20477 Absorbing Markov Chain Approach to Modelling Disruptions in Supply Chain Networks Perera, Supun; Bell, Michael G. H.; Kurauchi, Fumitaka; Kasthurirathna, Dharshana Recent developments in the area of network science has encouraged researchers to adopt a topological perspective in modelling Supply Chain Networks (SCNs). While topological models can provide macro level insights into the properties of SCN systems, the lack of specificity due to high level of abstraction in these models limit their real-world applicability, especially in relation to assessing the impact on SCNs arising due to individual firm or supply channel level disruptions. In particular, beyond the topological structure, a more comprehensive method should also incorporate the heterogeneity of various components (i.e. firms and inter-firm links) which together form the SCN. To fill the above gap, this work proposes using the idea of absorbing Markov chains to model disruption impacts on SCNs. Since this method does not require path enumeration to identify the number of supply chains which form the SCN, it is deemed more efficient compared to the other traditional methods. Wed, 01 May 2019 00:00:00 GMT https://hdl.handle.net/2123/20477 2019-05-01T00:00:00Z https://hdl.handle.net/2123/20385 Inland shipping network of LNG-fueled ships under emission control, - The case of China’s Belt and Road shipping corridor along the Yangtze river Hang, Yu; Bell, Michael G H; Fu, Xiaowen; Ged, Ying-En Liquefied natural gas (LNG) is used as an environmentally friendly source of fuel for inland river shipping in selected markets. However, the investment costs for bunkering stations and the price volatility of LNG have prevented it from being used more widely. In this study, we investigate the operation of LNG-fueled shipping in an inland river network, taking into account the effects of emissions regulations, the bunkering station locations, the price competitiveness of LNG, and the heterogeneity of the navigational conditions in inland rivers. The model is used to study bulk-cargo transportation along the Yangtze River, a major inland waterway of growing importance due to the Chinese government’s Belt and Road initiative. The modeling results suggest that the optimal shipping operations and bunkering station locations are significantly affected by the emissions regulations and incentive policies. In the Yangtze River market studied, low-sulfur fuels are the preferred option for carriers at a wide range of emission control levels. However, LNG only becomes an attractive fuel option when the emissions cap is set significantly below the current emissions level. For the promotion of LNG-fueled shipping, unit fuel subsidies are more effective than lump-sum capital subsidies for bunkering stations when the LNG price is high. However, the availability of bunker stations is an important factor when the LNG price volatility is considered. Overall, our results suggest that although LNG-fueled shipping is a promising option in the long term, the optimal industry policy on fuel use is dependent on multiple factors including the fuel price, types of subsidy, and emissions targets. Wed, 01 May 2019 00:00:00 GMT https://hdl.handle.net/2123/20385 2019-05-01T00:00:00Z https://hdl.handle.net/2123/20327 A review of (dis)aggregation and decomposition methods in traffic assignment Raadsen, Mark P.H.; Bliemer, Michiel C.J.; Bell, Michael G.H. In this study we provide a comprehensive review of the existing literature on (dis)aggregation and decomposition methods in traffic assignment. The study takes on two different perspectives. First, we explore existing methods and relate them to their impact on one or more of the components involved in traffic assignment. It is found that there exists a clear separation between a demand modelling point of view, i.e. travel demand and (geographical) zoning, and supply modelling oriented methods, i.e. network topology and network loading. At the same time, the interface between demand and supply, i.e. connector and centroid placement which is to be considered a special type of aggregation, has received conspicuously little attention in this context, even though it is shown to be of significant impact on modelling results. The second perspective in this study places the discussed aggregation methodologies in the broader perspective of clustering procedures. It is shown that most existing methods can be classified as supervised – or classification based – clustering procedures while relatively few studies explore other known approaches such as semi-supervised or unsupervised clustering techniques, at least from a purely traffic assignment model point of view. Lastly, we discuss how aggregation techniques can be deployed to construct multi-scale modelling environments. There is however a lack of methodology to construct such models consistently. It is hoped that this work provides a first step in the direction of such developments by providing an objective classification framework for existing (dis)aggregation and decomposition methods. Mon, 01 Apr 2019 00:00:00 GMT https://hdl.handle.net/2123/20327 2019-04-01T00:00:00Z https://hdl.handle.net/2123/20261 Supply Chain Carbon Management Goodarzi, Shadi; Fahimnia, Behnam; Sarkis, Joseph Sustainable supply chain and carbon management have seen a growing interest in the last decade due to the increasing concerns about global warming and climate change. Policymakers, researchers, and executives have taken various roles in efforts to better measure and control greenhouse gas emissions. This book chapter aims to discuss the current state of the art, and key motivations for businesses to decrease emissions, and different policies and regulations that have been designed to incentivize carbon reduction and enhance the environmental awareness of all stakeholders. The chapter also examines the methodologies for measuring and managing carbon emissions of an organization and its supply chain. Further, it discusses carbon management issues related to reverse logistics, life cycle assessment and double counting of emissions. Mon, 01 Apr 2019 00:00:00 GMT https://hdl.handle.net/2123/20261 2019-04-01T00:00:00Z https://hdl.handle.net/2123/20186 Airline Network Choice and Configuration Tu, Ningwen; Li, Zhi-Chun; Fu, Xiaowen; Lei, Zheng As an increasing number of countries liberalize their skies, some airlines, notably carriers in the Middle East, have been able to extend their hub-and-spoke networks beyond domestic borders. This allows them to serve international destinations without going through traditional gateway hubs, so that they can compete with airline alliances relying on the traditional dual-gateway, or the so-called “dog-bone” networks. This paper proposes a stochastic model to investigate the competition between airlines running traditional dog-bone and hub-and-spoke networks in a liberalizing inter-continental market. The proposed model considers the interactions among three types of stakeholders, namely a regulator that aims to maximize the expected social welfare by designating the locations of new gateways; airlines that maximize profits by optimizing the service offerings and airfares; passengers that minimize their own travel disutility. Such a model is applied to analyze the Europe - China aviation market, so that the comparative advantages of different networks can be examined and quantified. The modeling results provide evidence-based recommendations on airline competition and airport development, and infrastructure investment needs in markets being liberlized. Fri, 01 Mar 2019 00:00:00 GMT https://hdl.handle.net/2123/20186 2019-03-01T00:00:00Z https://hdl.handle.net/2123/20064 Collaboration as a service (CaaS) to fully integrate public transportation – lessons from long distance travel to reimagine Mobility as a Service Merkert, Rico; Bushell, James; Beck, Matthew Integrated mobility aims to improve multimodal integration to make public transport an attractive alternative to private transport. This paper critically reviews extant literature and current public transport governance frameworks of both macro and micro transport operators. Our aim is to extent the concept of Mobility-as-a-Service (MaaS), a proposed coordination mechanism for public transport that in our view is yet to prove its commercial viability and general acceptance. Drawing from the airline experience, we propose that smart ticketing systems, providing Software-as-a-Service (SaaS) can be extended with governance and operational processes that enhance their ability to facilitate Collaboration-as-a-Service (CaaS) to offer a reimagined MaaS 2.0 = CaaS + SaaS. Rather than using the traditional MaaS broker, CaaS incorporates operators more fully and utilises their commercial self-interest to deliver commercially viable and attractive integrated public transport solutions to consumers. This would also facilitate more collaboration of private sector operators into public transport with potentially new opportunities for taxi/rideshare/bikeshare operators and cross geographical transport providers (i.e. transnational multimodal operating companies) to integrate. Fri, 01 Mar 2019 00:00:00 GMT https://hdl.handle.net/2123/20064 2019-03-01T00:00:00Z https://hdl.handle.net/2123/20028 Context Dependent Process Heuristics and Choice Analysis: A note on the Behavioural Setting Guiding the Research Focus Hensher, David A. This note is written to remind us of the recognition of behavioural realism in the economic literature over 60 years ago, which seems to have been given limited recognition in the formal axiomatic development of economic theories commonly associated with the application of discrete choice models, especially where the interest is on obtaining welfare measures such as willingness to pay estimates of specific attributes for use in cost-benefit analysis. We need to be reminded from time to time of the importance of context dependency in defining a choice problem and the value that behavioural realism can add despite risks of violating often some axioms of economic rationality and utility maximisation. Fri, 01 Feb 2019 00:00:00 GMT https://hdl.handle.net/2123/20028 2019-02-01T00:00:00Z https://hdl.handle.net/2123/19936 Disassortativity in Biological and Supply Chain Networks Perera, Supun S.; Bell, Michael G.H.; Latty, Tanya Network science has allowed researchers to model complex real world systems as networks in order to identify non trivial topological patterns. Degree correlations (or assortativity) is one such non trivial topological property, which indicates the extent to which nodes with similar degrees tend to pair up with each other. Biological networks have long been known to display anti-degree correlations (disassortativity), where highly connected nodes tend to avoid linking with each other. However, the mechanism underlying this structural organisation remain not well understood. Recent work has suggested that in some instances, disassortativity can be observed merely as a model artefact due to simple network representations not allowing multiple link formations between the node pairs. This phenomena is known as structural disassortativity. In this paper, we analyse datasets from two distinct classes of networks, namely; man made supply chain networks and naturally occurring biological networks. We examine whether the observed disassortativity in these networks are structurally induced or owing to some external process. Degree preserving randomisation is used to generate an ensemble of null models for each network. Comparison of the degree correlation profiles of each network, against that of their degree preserving randomised counterparts reveal whether the observed disassortativity in each network is of structural nature or not. We find that in all biological networks, the observed disassortativity is of structural nature, meaning their disassortative nature can be fully explained by their respective degree distributions, without attribution to any underlying mechanism which drives the system towards disassortativity. However, in supply chain networks, we find one case where disassortativity is structurally induced and in other cases where it is mechanistically driven. We conclude by emphasizing on ruling out structural disassortativity in future research, prior to investigating mechanisms underlying disassortativity in networks. Fri, 01 Feb 2019 00:00:00 GMT https://hdl.handle.net/2123/19936 2019-02-01T00:00:00Z https://hdl.handle.net/2123/19903 Performance Contributors of Bus Rapid Transit Systems within the ITDP BRT Standard: An Ordered Choice Approach Li, Zheng; Hensher, David A. Bus rapid transit (BRT) is a mode of public transportation with relatively fast, flexible, comfortable, affordable and environment-friendly services. In this paper, the potential contributors to BRT performance are investigated within an ordered choice modelling framework, in which the dependent variable is the BRT standard (Gold, Silver, Bronze or Basic), developed by the Institute for Transportation and Development Policy (ITDP). The evaluation of an ordered logit model and an ordered probit model shows that the performance of the former is slightly better, which is chosen for the empirical application. The identified significant predictors are peak-hour speed, peak frequency, the average distance between stations, the length of dedicated busway, passing lanes at BRT station, covered station access, enhanced station environment, pre-board and automated fare collection and fare verification, and network integration. Based on a business-as-usual prediction and what-if analysis, this paper offers information for decision makers to plan a high-standard BRT system in line with the ITDP BRT standard. Tue, 01 Jan 2019 00:00:00 GMT https://hdl.handle.net/2123/19903 2019-01-01T00:00:00Z https://hdl.handle.net/2123/19758 Mode-agnostic mobility contracts: identifying broker/aggregator models for delivering mobility as a service (MaaS) Wong, Yale Z.; Hensher, David A.; Mulley, Corinne Mobility as a service (MaaS) promises a bold new future where bundled public transport and shared mobility options will provide consumers with seamless mobility on par with and exceeding that of private vehicle ownership. Whilst there is a growing body of work examining the market and end user demand for MaaS, there remains a limited understanding of the supply-side around new business models for delivering these integrated mobility services. Mobility broker/aggregator models have been proposed, but to date there exists no quantitative evidence to empirically test the conditions around which interested businesses might invest or supply in this new entrepreneurial model. In this paper, we propose the idea of mode-agnostic mobility contracts as the interface for bringing together specialised businesses as part of the new MaaS ecosystem. We identify the relevant attributes and attribute levels defining these contracts through an extensive interview and participatory research program with key stakeholders including MaaS operators, conventional transport operators, public transport authorities and consultancies, with a focus in the Nordic countries where such schemes are presently well advanced. These mobility contracts were then incorporated as part of a stated choice survey, and we document the face-to-face pilot used to finesse the survey instrument prior to the main survey. A preliminary mixed logit choice model based on collected data (n=202) is presented to showcase the potential of our stated preference survey to reveal what the market is willing to deliver in terms of MaaS and how the future service delivery ecosystem might look. Tue, 01 Jan 2019 00:00:00 GMT https://hdl.handle.net/2123/19758 2019-01-01T00:00:00Z