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Digital Twins for Assessing the Impact of Autonomous Vehicles on Built-Environment Changes

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Abstract

This chapter explores the multifaceted impact of Autonomous Vehicles (AVs) on the built environment and identifies limitations in traditional methodologies for prediction. Proposing a transformative solution, the chapter advocates for integrating Digital Twin technology as a dynamic and data-driven assessment tool to evaluate the impact of AVs on urban density, diversity, design, distance to other transits, and destination accessibility (5Ds). In this case, Urban Digital Twins offer real-time data analysis, modeling, and simulation of AVs interaction with the users and built environment, leveraging artificial intelligence/machine learning, and immersive 3D visualization. The discussion underscores the importance of a comprehensive Urban Digital Twin architecture to monitor and simulate the AV’s impacts on 5Ds and provide robust safety and security measures to ensure reliability of deploying AVs to the city environment. The chapter envisions a future where Urban Digital Twins play a pivotal role in informed decision-making, proactive urban planning, and adaptive development amid the transformative integration of Autonomous Vehicles.

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Introducing autonomous vehicles (AVs) reduces generalized transportation costs and encourages people to relocate. Understanding the subsequent changes in urban structure can help predict the future development of urban economies and policies. Transportation connects multiple zones in cities, and by improving traffic flow and ease directly impacts the economies of various markets. Each direct impact then also indirectly affects related markets. Therefore, a spatial computable general equilibrium model that connects multiple zones via a transportation network is suitable for analyzing the impact of a new transport system. This study constructs a model to simulate the effects of AVs on residential location choice. The results show that increased prevalence of AVs steers people toward suburbs with poor public transportation. Thus, high-income workers react more to technological progress, while low-income workers react more to lowered ownership costs. Consumers’ location choices and budgets also affect residential zones’ development. Therefore, regional policy goals must be clarified and appropriate target consumer groups set when introducing AVs.
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Autonomous vehicles (AVs) are pointed out as the technology that will reshape the concept of mobility, with significant implications for the economy, the environment, and society. This fact will bring new challenge to cities urban planning. Research to anticipate the AVs impacts, maximizing their benefits and reduce trade-offs are currently crucial. This work investigates the potential challenges and benefits of gradually replace internal combustion engine human driven vehicles with different penetration rates of AVs - 10%, 30%, 50%, 70%, 90%, and 100% - in urban roads of different characteristics, either in terms of traffic singularities or volumes, and its related implications on air quality. For that purpose, two urban areas with distinct features, Porto and Aveiro, were selected as case studies, and a modelling setup composed of a traffic model, an emission model, and a local air quality model was applied. The results revealed that the AVs benefits are directly linked with the urban design and the road characteristics. In the Aveiro case study, the AVs promoted positive changes with average reductions in daily NOx emissions (compared with the baseline scenario, without AVs) ranging between −2.1% (for C10%) and −7.7% (for C100%). In line with the emissions impacts, positive effects were found on air quality, with average reductions of NO2 concentrations up to −4% (for C100%). In Porto urban area, slight differences in NOx emissions were obtained (<2%), which implied no changes in the air quality levels. The distinct impact of AVs in the study areas is mostly explained by the traffic light coordination system and directional split distributions in the main roads. These results provide valuable insights to support decision-makers in the definition of strategies that allow the integration of these new emerging technologies in the road infrastructure, considering the features of the urban design, traffic profile and road characteristics.
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Artificial Intelligence (AI) technology is extensively applied in all walks of life with continuous acceleration of the construction of smart cities. The current research status of intelligent development of transportation infrastructure is classified and predicted oriented to smart cities, which is mainly based on space type, function type, and facility use. The classification is mainly between residents and vehicles, between and vehicles, and between vehicles and transportation systems. The related scholars analyzed that Digital Twins (DTs) technology and AI technology show significant advantages in the classification of transportation infrastructure and the management of transportation spatial information network. The intelligent development of transportation infrastructure is analyzed, and it is predicted in functional design, intelligent development, and effective integration with new media, aiming to provide a reference for the subsequent intelligent development and construction of transportation infrastructure in smart cities.
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The agent-based land use/transport model SILO/MITO/MATSim is adapted to simulate the impact of AVs on household relocation. The revised model accounts for the fact that households who own conventional cars are sensitive to parking availability at their dwelling. As AVs could park themselves anywhere, this sensitivity to parking is reduced for households who own AVs. Distance to work, which serves as a hard constraint for household relocation with conventional cars, becomes less critical for households who use an AV to commute as they may perform other activities while commuting. The induced demand of travel by AV is represented and leads to increased congestion. Several scenarios were designed to analyze the effects of reduced value of time for AV travel, parking restrictions and increase of congestion. The simulation shows that AVs will compete with transit and reduce transit ridership by three quarters. The average commute distance is expected to double, and the vehicle-kilometers traveled will increase by one third. The impact of AVs on the distribution of population, however, is marginal. The urban sprawl caused by less burdensome commuting is largely compensated by the increased attractiveness of core cities in the absence of parking issues for AVs.
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Implementing autonomous vehicles (AVs) can provide plenty of advantages, such as improving network capacity and reducing crashes. If morning commuters take AVs to the workplace, they can assign AVs an induced trip to a low-cost parking lot or even park AVs at their origins with no cost. This travel behavior might result in a more congested city network. This study firstly considers the equilibriums in route choice, mode choice, and parking lot choice in one optimization model. The solution algorithm is proposed to solve the optimization program iteratively. The Sioux Falls network is used to test the potential impacts of induced AV trips and the preference to choose an AV. The results using the test network find that scenarios with AVs increase the average travel time by approximately 50%, while 14.60% to 32.27% (scenario-based) of the area that is currently used as parking spaces can be re-purposed.
Article
Shared mobility is a promising travel mode in the era of autonomous driving. Travelers may no longer own a vehicle, but use shared autonomous vehicle (SAV) services. This study investigates the effects and feasibility of SAV-based shared mobility, which includes ride-sharing and car-sharing strategies, by using a data-driven modeling approach. Ride-sharing indicates that two trips with similar origin–destination information can be combined into a new one, whereas car-sharing indicates that trips can be fulfilled by a single vehicle consecutively. On the basis of license plate recognition data of Langfang, China, this study extracts the urban-scale vehicle travel demand information. Models for ride-sharing and car-sharing are formulated to generate SAV assignment strategies for fulfilling travel demands. This study reveals the prospects and potential problems of SAV-supported shared mobility at different development stages by setting a variety of scenarios with different participation levels of ride-sharing and car-sharing. The minimum fleet size to fulfil the vehicle travel demand in the road network and the total vehicle stock in the urban area are compared under different scenarios, and the effects of shared mobility on vehicle kilometers traveled (VKT) and parking demand are evaluated. This study also reveals the impacts of SAVs in a practical scenario, which is constructed based on an online survey. Results show that ride-sharing and car-sharing with high participation will lead to considerable benefits, i.e., reductions in fleet size, vehicle stock, and parking demand. Under the shared mobility scenario with 100% ride-sharing and car-sharing participation levels, one SAV can potentially replace 3.80 private conventional vehicles in the road network. However, ride-sharing and car-sharing exhibit opposite effects on VKT. Car-sharing alone increases VKT whereas car-sharing and ride-sharing together have the potential to decrease VKT. This study provides insights for understanding the development of shared mobility and facilitating the efficient utilization of SAVs.
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Sustainable urban road planning should endeavour to meet current and future traffic-related demands and achieve financial, environmental, and social benefits, which is a complex and interdisciplinary issue that needs to consider various factors and data. Multi-criteria decision making (MCDM) can provide reasonable solutions, and some existing studies integrated MCDM with geographic information system (GIS) technology. This paper presents an urban road planning approach based on digital twin (DT), MCDM, and GIS called DT-MCDM-GIS framework. DT can digitalize the physical world to provide various data for the whole process; MCDM can provide criteria and evaluation methods; GIS can provide an integrated environment for analysis. Building demolition and land use, traffic congestion, driving route selection habits, air quality, and noise are all considered in the framework for urban road planning. The proposed approach can provide a functional, economic, people-friendly, eco-friendly urban road planning scheme considering new road construction and existing old road widening to alleviate traffic congestion and provide an alternative route for drivers that conforms to their habits.
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Shared autonomous vehicles (SAVs) can have significant impacts on the transport system and land use by replacing private vehicles. Sharing vehicles without drivers is expected to reduce parking demand, and as a side effect, increase congestion owing to the empty fleets made by SAVs picking up travelers and relocating. Although the impact may not be uniform over a region of interest owing to the heterogeneity of travel demand distribution and network configuration, few studies have debated such impact at a local scale, such as in transportation analysis zones (TAZs). To understand the impact in relation to geographical situations, this study aims to estimate the impacts of SAVs at the local scale by simulating their operation on a developed simulator. Using the mainland of Okinawa, Japan as a case study, it was found that parking demand was reduced the most in residence-dominant zones in terms of quantity and office-dominant zones in terms of proportion. As a side effect of replacing private vehicles with SAVs, empty fleets increase congestion, particularly at the periphery of the city. Overall, the results show the heterogeneous impacts of the SAVs at the TAZ level on both land use and traffic, thus suggesting the importance of developing appropriate strategies for urban and transport planning when considering the characteristics of the zones.
Article
This study considers a closed core-suburb city connected by a highway. Two travel modes, namely on-demand and frequency-based autonomous vehicles (AVs), are used for commuting between the suburb and urban core. Each resident attempts to maximize his/her individual utility with consideration to environment quality by choosing a residential location, travel mode, departure time, and non-housing composite consumption good within an expenditure budget. The traffic equilibria are analytically derived for two right-of-way policies, namely (i) the two travel modes sharing the right-of-way and (ii) frequency-based AVs-priority, with consideration of the effect of AVs on travel and urban characteristics. It was found from the analytical results that at any level of AV automation, adopting the frequency-based AVs-priority policy can reduce travel cost for suburban residents while alleviating traffic congestion. Furthermore, an increase in AV automation level results in an increase in expected trip time if the highway capacity is less elastic than the value of travel time for on-demand AVs with respect to the automation level. In addition, if the environment quality depends solely on the residential density, with an increasing level of AV automation, the suburban population and the number of residents using on-demand AVs increase, the land rent in the urban core reduces, the suburb expands, and the utility for all residents increases. These findings help to provide a better understanding of the interactions between AVs, travel and urban characteristics, and serve as a valuable reference to transportation-urban planning in the era of driving automation.
Article
Autonomous vehicle technology and its enabled mobility services are evolving at a more rapid pace than the understanding of the infrastructure required for them to be efficiently and safely implemented. This has not been systematically investigated in literature or practice. This research makes exploratory efforts to investigate this research area by examining and evaluating the infrastructure requirements needed to support autonomous vehicles. It formulates an infrastructure change guideline and an evaluation framework to prioritise the safety, efficiency and accessibility when integrating autonomous vehicles alongside conventional vehicles and multimodal users such as public transport commuters and pedestrians. The case study results show that for different type of regions, being a regional commercial and transportation hub in a residential area and a regional CBD street in a multimodal and spatially limited area, different arrangement and trade-offs can be made. Promisingly, the proposed guideline and framework work sufficiently, and serve as a first step towards a more systematic guideline for autonomous vehicle integration. The outcome of the research consists of a review of approaches that can guide urban planners and other users to understand and prioritise the implementation of autonomous vehicles.
Article
Automated vehicles (AVs) have great potential to revolutionize the transportation sector and landscapes of future cities. The impacts of AVs on urban space, however, are far from clear. Mobility-on-Demand (MOD) services, on the other hand, are readily available in many places. This study seeks to explore (1) how Automated Mobility-on-Demand (AMOD) might affect urban residents' levels of accessibility and their residential relocation decisions; and (2) how these impacts might vary across space and socioeconomic groups. We use an agent-based microsimulation platform to assess two future AMOD scenarios in Singapore relative to a baseline. Results suggest that the addition of AMOD could enhance the overall accessibility of the population, but not if private transport modes, including private cars, taxis, and human-driven on-demand services, are prohibited. On the other hand, if private modes are eliminated, AMOD could alleviate inequality in accessibility as it appears to benefit the disadvantaged socioeconomic groups to a larger extent. We also find that AMOD deployment would not induce outward migration, nor would it increase home-work location imbalance. This study demonstrates how large-scale microsimulation can be leveraged to assess AMOD scenarios. The findings have some implications for preparing for the inevitable and potentially disruptive emergence of AVs.
Article
Autonomous vehicles (AVs) hold great promise for increasing the capacity of existing roadways and intersections, providing more mobility to a wider range of people, and are likely to reduce vehicle crashes. However, AVs are also likely to increase travel demand which could diminish the potential for AVs to reduce congestion and cause emissions of greenhouse gases (GHG) and other air pollutants to increase. Therefore, understanding how AVs will affect travel demand is critical to understanding their potential benefits and impacts. We evaluate how adoption of AVs affects travel demand, congestion and vehicle emissions over several decades using an integrated travel demand, land-use and air quality modeling framework for the Albuquerque, New Mexico metropolitan area. We find that AVs are likely to increase demand and GHG emissions as development patterns shift to the region's periphery and trips become longer. Congestion declines along most roadways as expanded capacity from more efficient AV operation outpaces increasing demand. Most of the population can also expect a reduction in exposure to toxic vehicle emissions. Some locations will experience an increase in air pollution exposure and traffic congestion from changes in land-use and traffic patterns caused by the adoption of AVs.
Article
Shared autonomous vehicles (SAVs) have been widely studied in the recent literature. Agent-based simulations and theoretical models have extensively explored the effects on travel service, fleet size, and congestion using heuristic dispatching strategies to match SAVs with on-demand passengers. A major question that simulations have sought to address is the service rate or replacement rate: the number of passengers each SAV can serve. Thus far, the service rate has mostly been estimated through simulation. This paper investigates an analytical max-pressure dispatch policy, which aims to maximize passenger throughput under any stochastic demand pattern, which takes the form of a model predictive control algorithm. An analytical proof using Lyapunov drift techniques is presented to show that the dispatch policy achieves maximum stability. The service rate and minimum fleet sizes are derived analytically in this paper and can be achieved with the proposed dispatch policy. Simulation results show that the maximum stable demand is linearly related to the fleet size given. Also, it demonstrates how asymmetric demand necessitates rebalancing trips that affect service rates. Even though decreasing average waiting time is not the primary goal of this paper, stability ensures bounded waiting times, which is demonstrated in simulation.
Article
It is anticipated that Shared Autonomous Vehicles (SAV) may revolutionise the way people travel as it may lead to less ownership of vehicles and a gradual increase in demand responsive mobility. These vehicles are likely to able to park far away from popular destinations after they drop off their clients. It is, therefore, capable of releasing parking spaces around central business districts while cutting down parking search time and cost. But the magnitude at which these spaces will be released in relation to SAV fleet size is not currently known. This work therefore seeks to understand this relationship using the University of the West of England, Frenchay campus characterised by 23 carparks of varying size – as a case study – to quantitatively understand these impacts. This was done by simulating 2181 parking slot within the campus; motor traffic (SAVs and non-SAVs); and the route networks from the 3 entry stations – East, North and Longmead entrances – to each parking slot. Carpark preference data was obtained and analysed. It formed the context on which drivers choose a parking space within the system. These data alongside with the graphical features of the Frenchay campus were imported into ARENA simulation toolkit: a discrete event-based simulation software. Results indicated the obvious that as SAV fleet size increases, spaces released also increases but in addition, individual carpark reacted dynamically in response to the demand on neighbouring carparks. It also showed that there is currently an excess of parking supply compared to the number of vehicles entering the campus daily. It further discusses the potential of multiple occupancy SAVs to further release all parking spaces on the Frenchay campus. The work concludes with the potentials for this research to be extended to a citywide approach with a special interest in the ability for SAV to release kerb parking spaces.
Article
The coming of automated vehicles (AVs) and Mobility-on-Demand (MoD services) is expected to reduce urban parking demand and correspondingly alter the urban parking landscape in a significant way. Multiple modeling efforts have already demonstrated that Shared AVs (SAVs) have promising potential to decrease urban parking demand. However, previous studies have only examined SAV parking demand at one point in time, with various market penetrations. It remains unclear what the demand reduction trajectory will be like during the transition period when there is a mix of SAVs, Privately-Owned AVs (PAVs), Shared Conventional Vehicles (SCVs), and Conventional Private Vehicles (CPVs). This study fills this gap by developing an agent-based simulation model to examine the spatially and temporally explicit parking reduction trends with mixed travel modes from 2020–2040. The results indicate that in the most optimal AV and MoD adoption scenario, the parking demand will decrease by over 20% after 2030, especially in core urban areas. Meanwhile, the parking demand in residential zones may double, which could lead to transportation equity concerns. Additionally, parking relocation may also induce environmental issues by generating a considerable amount of empty Vehicle Miles Traveled (VMT). To reap the benefits brought by AVs and MoD systems and to mitigate the accompanying social and environmental issues, our results suggest that proactive policymakers in the next decade will need to modify land use regulations for both new developments and existing parking infrastructure in commercial and residential zones, as well as update travel demand management policies.
Article
The goal of this study is to assess and quantify the potential employment accessibility benefits of shared-use automated vehicle (AV) mobility service (SAMS) modes across a large diverse metropolitan region considering heterogeneity in the working population. To meet this goal, this study proposes employing a welfare-based (i.e. logsum-based) measure of accessibility, obtained via estimating a hierarchical work destination-commute mode choice model. The employment accessibility logsum measure incorporates the spatial distribution of worker residences and employment opportunities, the attributes of the available commute modes, and the characteristics of individual workers. The study further captures heterogeneity of workers using a latent class analysis (LCA) approach to account for different worker clusters valuing different types of employment opportunities differently, in which the socio-demographic characteristics of workers are the LCA model inputs. The accessibility analysis results in Southern California indicate: (i) the accessibility benefit differences across latent classes are modest but young workers and low-income workers do see higher benefits than high-and middle-income workers; (ii) there are substantial spatial differences in accessibility benefits with workers living in lower density areas benefiting more than workers living in high-density areas; (iii) nearly all the accessibility benefits come from the SAMS-only mode as opposed to the SAMS+Transit mode; and (iv) the SAMS cost per mile assumption significantly impacts the magnitude of the overall employment accessibility benefits.
Article
Objective Digitisation and automation are expected to change the transport system and settlement structures in a disruptive way. Due to new developments in sensor and communication technology different business models of automated vehicles (AV) - such as private AV, car-sharing-AV, ride-sharing-AV and public transport-AV – are likely to enter the transport market. Further, different penetration rates of AVs, extension of user groups (elderly and young, people without driving licenses etc.), different cost scenarios of AV veh-kms, parking regimes/fees, etc. will have significant impact on future transport demand. The objective of the work presented in this paper was to develop a simulation-based approach to analyse the potential impacts of different vehicle automation scenarios in Austria. Method A multitude of complex cause-effect-chains and feedback loops characterise the relationship between AV take up, travel demand and environmental effects. The method of System Dynamics (SD) is designed to deal with such complexities. As a first step the qualitative method of Causal Loop Diagrams (CLD) was used to identify all potential automation related factors influencing the attractiveness of car and public transport use. In a second step the identified factors were coded into an operational version of the Stock-Flow based land use and transport interaction model MARS (Metropolitan Activity Relocation Simulator). As a third step sensitivity tests and scenarios were defined and simulated. Finally the resulting quantitative impacts were assessed and discussed. Results In this paper we describe briefly how MARS was adapted to be able to simulate the effects of different AV-take up rates on the national level of Austria. Simulation results are presented for the scenario elements road capacity, remote parking, value of travel time, access for new user groups in the business models private car, car-sharing and ride-sharing and automation of the first and last mile in public transport. The results show that with a fleet share of 90% of private AVs in 2050, the nationwide changes in veh-kms travelled are between −2% (impact on road capacity) and +22 percent (new user groups in the case of AVs as private cars). Policy implications An uncontrolled market take-up of AVs into the transport system will very likely increase the dependency on motorised transport, veh-kms driven and related emissions. Compensating policies have to be implemented in parallel to avoid un-sustainable developments.
Article
We adapt the classic monocentric city model to consider three main topics related to the possible widespread adoption of autonomous vehicles (AVs): sprawl, energy consumption, and housing affordability. AVs are modeled to reduce marginal commuting costs and in some cases, reduce demand for center-city and residential parking. This creates opposing forces that lead to sprawl in some models and increasing density in others. All models point to welfare increases, but also increases to energy consumption due to longer commutes, greater traffic congestion, and higher productivity, calling into question claims that autonomous vehicles will save energy. In most models, AVs lead to greater housing affordability by making suburban areas more accessible, and by reclaiming land that was previously used for parking. Effects of AVs on cities are substantial and depend on the manner in which this new technology is implemented.