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1. Economic Viability and Emissions of Multimodal Transportation Infrastructure in a Changing Arctic

   https://doi.org/10.1175/WCAS-D-21-0151.1  

   Goldstein, Michael_A; Lynch, Amanda_H; Yan, Ruitian; Veland, Siri; Talleri, William (July 2022, Weather, Climate, and Society)

   Abstract As Arctic open water increases, shipping activity to and from mid- and western Russian Arctic ports to points south has notably increased. A number of Arctic municipalities hope increased vessel traffic will create opportunities to become a major transshipment hub. However, even with more traffic passing these ports, it might still be economically cheaper to offload cargo at a more southern port, which may also result in lower emissions. Ultimately, the question of whether to use a transshipment in the Arctic versus an established major European port is determined by the relative costs (or emissions) of sea versus land travel. This study calculates the relative competitiveness of six Norwegian coastal cities as multimodal hubs for shipments. We quantify the relative prices and CO₂emissions for sea and land travel for routes starting at the Norwegian–Russian sea border with an ultimate destination in central Europe and find that all existing routes are not competitive with routes using the major existing Port of Rotterdam (Netherlands); even with investments in port expansion and modernization, they would be underutilized regardless of an increase in vessel traffic destined for central Europe. We then examine under what relative prices (emissions) these routes become economically viable or result in lower emissions than using existing southern ports. Notably, the cheapest routes generally produce the lowest emissions, and the most expensive routes tend to have the largest emissions. Communities should consider relative competitiveness prior to making large infrastructure investments. While some choices are physically possible, they may not be economically viable. Significance StatementClimate change, while disruptive, can also create new opportunities. Many Arctic cities hope to become a major transshipping hub as declining sea ice opens new shipping routes from western and mid-Russian Arctic ports to European ports. This paper quantifies the relative competitiveness of six Norwegian coastal cities as multimodal transportation hubs and finds that they are uncompetitive with the more southern port in Rotterdam (Netherlands). We also show that the most economically competitive routes have lower direct emissions. Thus, while Arctic ports provide critical services in support of local and regional economic activity, even with year-round Arctic navigation Arctic ports’ development into major transshipment hubs for cargo destined for more distant locations may be neither economically viable nor desirable. 

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2. Towards demand-oriented flexible rerouting of public transit under uncertainty

   https://doi.org/10.1145/3313237.3313302  

   Nannapaneni, Saideep; Dubey, Abhishek (January 2019, Proceedings of the Fourth Workshop on International Science of Smart City Operations and Platforms Engineering)

   This paper proposes a flexible rerouting strategy for the public transit to accommodate the spatio-temporal variation in the travel demand. Transit routes are typically static in nature, i.e., the buses serve well-defined routes; this results in people living in away from the bus routes choose alternate transit modes such as private automotive vehicles resulting in ever-increasing traffic congestion. In the flex-transit mode, we reroute the buses to accommodate high travel demand areas away from the static routes considering its spatio-temporal variation. We perform clustering to identify several flex stops; these are stops not on the static routes, but with high travel demand around them. We divide the bus stops on the static routes into critical and non-critical bus stops; critical bus stops refer to transfer points, where people change bus routes to reach their destinations. In the existing static scheduling process, some slack time is provided at the end of each trip to account for any travel delays. Thus, the additional travel time incurred due to taking flexible routes is constrained to be less than the available slack time. We use the percent increase in travel demand to analyze the effectiveness of the rerouting process. The proposed methodology is demonstrated using real-world travel data for Route 7 operated by the Nashville Metropolitan Transit Authority (MTA). 

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3. CityLines: Hybrid Hub-and-Spoke Urban Transit System

   https://doi.org/10.1145/3139958.3139995  

   Liu, Guanxiong; Li, Yanhua; Zhang, Zhi-Li; Luo, Jun; Zhang, Fan (November 2017, ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (GIS))

   Rapid urbanization has posed significant burden on urban transportation infrastructures. In today's cities, both private and public transits have clear limitations to fulfill passengers' needs for quality of experience (QoE): Public transits operate along fixed routes with long wait time and total transit time; Private transits, such as taxis, private shuttles and ride-hailing services, provide point-to-point transits with high trip fare. In this paper, we propose CityLines, a transformative urban transit system, employing hybrid hub-and-spoke transit model with shared shuttles. Analogous to Airlines services, the proposed CityLines system routes urban trips among spokes through a few hubs or direct paths, with travel time as short as private transits and fare as low as public transits. CityLines allows both point-to-point connection to improve the passenger QoE, and hub-and-spoke connection to reduce the system operation cost. Our evaluation results show that CityLines framework can achieve both short travel time and high ride-sharing ratio. 

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4. Predicting Wildlife Trafficking Routes with Differentiable Shortest Paths

   Ferber, A. (May 2023, Part of the Lecture Notes in Computer Science book series (LNCS,volume 13884))

   Cire, A.A. (Ed.)

   Wildlife trafficking (WT), the illegal trade of wild fauna, flora, and their parts, directly threatens biodiversity and conservation of trafficked species, while also negatively impacting human health, national security, and economic development. Wildlife traffickers obfuscate their activities in plain sight, leveraging legal, large, and globally linked transportation networks. To complicate matters, defensive interdiction resources are limited, datasets are fragmented and rarely interoperable, and interventions like setting checkpoints place a burden on legal transportation. As a result, interpretable predictions of which routes wildlife traffickers are likely to take can help target defensive efforts and understand what wildlife traffickers may be considering when selecting routes. We propose a data-driven model for predicting trafficking routes on the global commercial flight network, a transportation network for which we have some historical seizure data and a specification of the possible routes that traffickers may take. While seizure data has limitations such as data bias and dependence on the deployed defensive resources, this is a first step towards predicting wildlife trafficking routes on real-world data. Our seizure data documents the planned commercial flight itinerary of trafficked and successfully interdicted wildlife. We aim to provide predictions of highly-trafficked flight paths for known origin-destination pairs with plausible explanations that illuminate how traffickers make decisions based on the presence of criminal actors, markets, and resilience systems. We propose a model that first predicts likelihoods of which commercial flights will be taken out of a given airport given input features, and then subsequently finds the highest-likelihood flight path from origin to destination using a differentiable shortest path solver, allowing us to automatically align our model’s loss with the overall goal of correctly predicting the full flight itinerary from a given source to a destination. We evaluate the proposed model’s predictions and interpretations both quantitatively and qualitatively, showing that the predicted paths are aligned with observed held-out seizures, and can be interpreted by policy-makers 

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5. CityLines: Designing Hybrid Hub-and-Spoke Transit System with Urban Big Data

   https://doi.org/10.1109/TBDATA.2018.2840222  

   Li, Yanhua; Liu, Guanxiong; Zhang, Zhi-Li; Luo, Jun; Zhang, Fan (May 2018, IEEE Transactions on Big Data)

   Rapid urbanization has posed significant burden on urban transportation infrastructures. In today's cities, both private and public transits have clear limitations to fulfill passengers' needs for quality of experience (QoE): Public transits operate along fixed routes with long wait time and total transit time; Private transits, such as taxis, private shuttles and ride-hailing services, provide point-to-point transits with high trip fare. In this paper, we propose CityLines, a transformative urban transit system, employing hybrid hub-and-spoke transit model with shared shuttles. Analogous to Airlines services, the proposed CityLines system routes urban trips among spokes through a few hubs or direct paths, with travel time as short as private transits and fare as low as public transits. CityLines allows both point-to-point connection to improve the passenger QoE, and hub-and-spoke connection to reduce the system operation cost. To evaluate the performance of CityLines, we conduct extensive data-driven experiments using one-month real-world trip demand data (from taxis, buses and subway trains) collected from Shenzhen, China. The results demonstrate that CityLines reduces 12.5%-44% average travel time, and aggregates 8.5%-32.6% more trips with ride-sharing over other implementation baselines. 

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