Optimization for Manhattan's traffic: ridesharing for vehicles for hire

Ridesharing es refereix a l’agrupació de diversos passatgers en un mateix vehicle, principalment com a resposta de l’increment del nombre de vehicles i de trànsit, i l'empitjorament de la qualitat de l'aire que ha estat observat en ciutats grans i altament poblades; i com a mètode per a reduir els costos de les companyies VTCs i els seus clients. Aquest treball simula l’agrupació de passatgers per als VTC de Manhattan; aplicant primer l’algoritme descrit a "On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment" (Javier Alonso-Mora et al, PNAS, 2017) canviant la funció de costos per definir el nivell de priorització entre la disminució del trànsit i l'empitjorament de la qualitat del servei; i aplicant després un algoritme de rebalancing per permetre als vehicles moure’s per recollir en el futur altres passatgers. Finalment, s’analitza l'efecte d'aquests paràmetres en els resultats globals de trànsit a Manhattan, el retard sofert pels passatgers i la mida de la flota utilitzada.Ridesharing se refiere a la agrupación de varios pasajeros en un mismo vehículo, principalmente como respuesta al incremento de número de vehículos y tráfico, y al empeoramiento de la calidad del aire que se han observado en ciudades grandes y altamente pobladas; y como método para reducir los costes de las compañías VTCs y sus clientes. Este trabajo simula la agrupación de pasajeros para los VTC de Manhattan: aplicando primero el algoritmo descrito en "On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment" (Javier Alonso-Mora et al, PNAS, 2017) cambiando la función de coste para permitir definir el nivel de priorización entre disminución del tráfico y empeoramiento de la calidad del servicio; y segundo un algoritmo de rebalancing que permita a los vehículos moverse para recoger en el futuro a otros pasajeros, para distintos valores de ponderación entre el aumento del tráfico por los vehículos vacíos y la disminución de la cantidad de vehículos necesarios. Finalmente, se analiza el efecto de estos parámetros sobre los resultados globales del tráfico de Manhattan, el retraso sufrido por los pasajeros y el tamaño de la flota usada.Ridesharing refers to the pooling of several passengers into a vehicle, mainly as a response to the increase of number of vehicles, rise in traffic congestion and worsening of air quality that have been observed in big and highly populated cities; and as a way to reduce costs for both companies of vehicles for hire and their clients. This work simulates the pooling of passengers of vehicles for hire in Manhattan: applying first the algorithm described in "On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment" (Javier Alonso-Mora et al, PNAS, 2017), changing the cost function to allow different levels of priorization between decreasing traffic and worsening the service quality; and applying then a rebalancing algorithm that allows vehicles to move to attend future requests, for several weights of rise in traffic due to empty vehicles versus the decrease in number of vehicles needed. Finally, the effect of these parameters over the global traffic of Manhattan, the delay suffered by the passengers and the fleet size used is analyzed.Outgoin

Dynamic carpooling in urban areas: design and experimentation with a multi-objective route matching algorithm

This paper focuses on dynamic carpooling services in urban areas to address the needs of mobility in real-time by proposing a two-fold contribution: a solution with novel features with respect to the current state-of-the-art, which is named CLACSOON and is available on the market; the analysis of the carpooling services performance in the urban area of the city of Cagliari through emulations. Two new features characterize the proposed solution: partial ridesharing, according to which the riders can walk to reach the driver along his/her route when driving to the destination; the possibility to share the ride when the driver has already started the ride by modeling the mobility to reach the driver destination. To analyze which features of the population bring better performance to changing the characteristics of the users, we also conducted emulations. When compared with current solutions, CLACSOON allows for achieving a decrease in the waiting time of around 55% and an increase in the driver and passenger success rates of around 4% and 10%, respectively. Additionally, the proposed features allowed for having an increase in the reduction of the CO2 emission by more than 10% with respect to the traditional carpooling service

Privacy-Preserving Vehicle Assignment for Mobility-on-Demand Systems

Urban transportation is being transformed by mobility-on-demand (MoD) systems. One of the goals of MoD systems is to provide personalized transportation services to passengers. This process is facilitated by a centralized operator that coordinates the assignment of vehicles to individual passengers, based on location data. However, current approaches assume that accurate positioning information for passengers and vehicles is readily available. This assumption raises privacy concerns. In this work, we address this issue by proposing a method that protects passengers' drop-off locations (i.e., their travel destinations). Formally, we solve a batch assignment problem that routes vehicles at obfuscated origin locations to passenger locations (since origin locations correspond to previous drop-off locations), such that the mean waiting time is minimized. Our main contributions are two-fold. First, we formalize the notion of privacy for continuous vehicle-to-passenger assignment in MoD systems, and integrate a privacy mechanism that provides formal guarantees. Second, we present a scalable algorithm that takes advantage of superfluous (idle) vehicles in the system, combining multiple iterations of the Hungarian algorithm to allocate a redundant number of vehicles to a single passenger. As a result, we are able to reduce the performance deterioration induced by the privacy mechanism. We evaluate our methods on a real, large-scale data set consisting of over 11 million taxi rides (specifying vehicle availability and passenger requests), recorded over a month's duration, in the area of Manhattan, New York. Our work demonstrates that privacy can be integrated into MoD systems without incurring a significant loss of performance, and moreover, that this loss can be further minimized at the cost of deploying additional (redundant) vehicles into the fleet.Comment: 8 pages; Submitted to IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 201

Shared Mobility - Operations and Economics

In the last decade, ubiquity of the internet and proliferation of smart personal devices have given rise to businesses that are built on the foundation of the sharing economy. The mobility market has implemented the sharing economy model in many forms, including but not limited to, carsharing, ride-sourcing, carpooling, taxi-sharing, ridesharing, bikesharing, and scooter sharing. Among these shared-use mobility services, ridesharing services, such as peer-to-peer (P2P) ridesharing and ride-pooling systems, are based on sharing both the vehicle and the ride between users, offering several individual and societal benefits. Despite these benefits, there are a number of operational and economic challenges that hinder the adoption of various forms of ridesharing services in practice. This dissertation attempts to address these challenges by investigating these systems from two different, but related, perspectives. The successful operation of ridesharing services in practice requires solving large-scale ride-matching problems in short periods of time. However, the high computational complexity and inherent supply and demand uncertainty present in these problems immensely undermines their real-time application. In the first part of this dissertation, we develop techniques that provide high-quality, although not necessarily optimal, system-level solutions that can be applied in real time. More precisely, we propose a distributed optimization technique based on graph partitioning to facilitate the implementation of dynamic P2P ridesharing systems in densely populated metropolitan areas. Additionally, we combine the proposed partitioning algorithm with a new local search algorithm to design a proactive framework that exploits historical demand data to optimize dynamic dispatching of a fleet of vehicles that serve on-demand ride requests. The main purpose of these methods is to maximize the social welfare of the corresponding ridesharing services. Despite the necessity of developing real-time algorithmic tools for operation of ridesharing services, solely maximizing the system-level social welfare cannot result in increasing the penetration of shared mobility services. This fact motivated the second stream of research in this dissertation, which revolves around proposing models that take economic aspects of ridesharing systems into account. To this end, the second part of this dissertation studies the impact of subsidy allocation on achieving and maintaining a critical mass of users in P2P ridesharing systems under different assumptions. First, we consider a community-based ridesharing system with ride-back guarantee, and propose a traveler incentive program that allocates subsidies to a carefully selected set of commuters to change their travel behavior, and thereby, increase the likelihood of finding more compatible and profitable matches. We further introduce an approximate algorithm to solve large-scale instances of this problem efficiently. In a subsequent study for a cooperative ridesharing market with role flexibility, we show that there may be no stable outcome (a collusion-free pricing and allocation scheme). Hence, we introduced a mathematical formulation that yields a stable outcome by allocating the minimum amount of external subsidy. Finally, we propose a truthful subsidy scheme to determine matching, scheduling, and subsidy allocation in a P2P ridesharing market with incomplete information and a budget constraint on payment deficit. The proposed mechanism is shown to guarantee important economic properties such as dominant-strategy incentive compatibility, individual rationality, budget-balance, and computational efficiency. Although the majority of the work in this dissertation focuses on ridesharing services, the presented methodologies can be easily generalized to tackle related issues in other types of shared-use mobility services.PHDCivil EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169843/1/atafresh_1.pd

Heuristics for New Problems Arising in the Transport of People and Goods

The Vehicle Routing Problem (VRP) and its numerous variants are amongst the most widely studied in the entire Operations Research literature, with applications in fields includ- ing supply chain management, journey planning and vehicle scheduling. In this thesis, we focus on three problems from two fields with a wide reach; the design of public trans- port systems and the robust routing of delivery vehicles. Each chapter investigates a new setting, formulates an optimization problem, introduces various solution methods and presents computational experiments highlighting salient points. The first problem involves commuters who use a flexible shuttle service to travel to a main transit hub, where they catch a fixed route public transport service to their true destina- tion. In our variant, passengers must forgo some of the choices they had in previous ver- sions; the service provider chooses the specific hub passengers are taken to (provided all relevant timing constraints are satisfied). This introduces both complexities and opportu- nities not seen in other VRP variants, so we present two solution methods tailored for this problem. An extensive computational study over a range of networks shows this flexibility allows significant cost savings with little impact on the quality of service received. The second problem involves dynamic ridesharing schemes and one of their most per- sistent drawbacks: the requirement to attract a large number of users during the start up phase. Although this is influenced by many factors, a significant consideration is the per- ceived uncertainty around finding a match. To address this, the service provider may wish to employ a small number of their own private drivers, to serve riders who would oth- erwise remain unmatched. We explore how this could be formulated as an optimization problem and discuss the objectives and constraints the service provider may have. We then describe a special structure inherent to the problem and present three different so- lution methods which exploit this. Finally, a broad computational study demonstrates the potential benefits of these dedicated drivers and identifies environments in which they are most useful. The third problem comes from the field of logistics and involves a large delivery firm serving an uncertain customer set. The firm wishes to build low cost delivery routes that remain efficient after the appearance and removal of some customers. We formulate this problem and present a heuristic which is both computationally cheaper and more versatile than comparative exact methods. A wide computational study illustrates our heuristic’s predictive power and its efficacy compared to natural alternative strategies

INQUIRIES IN INTELLIGENT INFORMATION SYSTEMS: NEW TRAJECTORIES AND PARADIGMS

Rapid Digital transformation drives organizations to continually revitalize their business models so organizations can excel in such aggressive global competition. Intelligent Information Systems (IIS) have enabled organizations to achieve many strategic and market leverages. Despite the increasing intelligence competencies offered by IIS, they are still limited in many cognitive functions. Elevating the cognitive competencies offered by IIS would impact the organizational strategic positions. With the advent of Deep Learning (DL), IoT, and Edge Computing, IISs has witnessed a leap in their intelligence competencies. DL has been applied to many business areas and many industries such as real estate and manufacturing. Moreover, despite the complexity of DL models, many research dedicated efforts to apply DL to limited computational devices, such as IoTs. Applying deep learning for IoTs will turn everyday devices into intelligent interactive assistants. IISs suffer from many challenges that affect their service quality, process quality, and information quality. These challenges affected, in turn, user acceptance in terms of satisfaction, use, and trust. Moreover, Information Systems (IS) has conducted very little research on IIS development and the foreseeable contribution for the new paradigms to address IIS challenges. Therefore, this research aims to investigate how the employment of new AI paradigms would enhance the overall quality and consequently user acceptance of IIS. This research employs different AI paradigms to develop two different IIS. The first system uses deep learning, edge computing, and IoT to develop scene-aware ridesharing mentoring. The first developed system enhances the efficiency, privacy, and responsiveness of current ridesharing monitoring solutions. The second system aims to enhance the real estate searching process by formulating the search problem as a Multi-criteria decision. The system also allows users to filter properties based on their degree of damage, where a deep learning network allocates damages in 12 each real estate image. The system enhances real-estate website service quality by enhancing flexibility, relevancy, and efficiency. The research contributes to the Information Systems research by developing two Design Science artifacts. Both artifacts are adding to the IS knowledge base in terms of integrating different components, measurements, and techniques coherently and logically to effectively address important issues in IIS. The research also adds to the IS environment by addressing important business requirements that current methodologies and paradigms are not fulfilled. The research also highlights that most IIS overlook important design guidelines due to the lack of relevant evaluation metrics for different business problems