Sustainability

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20 pages, 23510 KiB

Open AccessArticle

Going My Way? Understanding Curb Management and Incentive Policies to Increase Pooling Service Use and Public Transit Linkages in the San Francisco Bay Area

by Wesley Darling, Jacquelyn Broader, Adam Cohen and Susan Shaheen

Sustainability 2023, 15(18), 13964; https://doi.org/10.3390/su151813964 - 20 Sep 2023

Cited by 1 | Viewed by 1183

Abstract

Despite lower user costs, only 20% to 40% of transportation network company (TNC) users select a pooled, or shared, ride option. Why are existing TNC users not selecting the pooled option or using TNCs to connect to public transit, and what role do [...] Read more.

Despite lower user costs, only 20% to 40% of transportation network company (TNC) users select a pooled, or shared, ride option. Why are existing TNC users not selecting the pooled option or using TNCs to connect to public transit, and what role do built environment features and incentives play in their decision? This study explores the factors that influence TNC user decisions through a multi-method approach comprising photovoice small group discussions and a workshop. Between March 2021 and May 2021, 15 San Francisco Bay Area TNC users shared photographs they took of TNC pick-up locations through two-to-three-person guided small group discussions. The photos revealed that users prefer waiting in retail or in well-lit, good-visibility locations. Participants’ primary concern was personal safety, particularly female users who may take additional precautions when walking to pick-up locations and waiting for and taking rides. In July 2021, 12 photovoice participants and 5 stakeholders provided feedback on key findings from the photography discussions. The pooling improvement strategies identified include the following: designated TNC stops with lighting and marked pick-up areas; enhanced in-app safety features; TNC partnerships with employers and retailers to incentivize riders; and mode transfer discounts for connecting TNCs to public transit. The findings suggest that safety related to the built environment plays an outsized role in a TNC user’s decision to pool or connect to public transit, and the out-of-vehicle portion of the TNC trip should be equally considered when developing policies to increase pooling. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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15 pages, 5172 KiB

Open AccessArticle

Ebike Sharing vs. Bike Sharing: Demand Prediction Using Deep Neural Networks and Random Forests

by Maren Schnieder

Sustainability 2023, 15(18), 13898; https://doi.org/10.3390/su151813898 - 19 Sep 2023

Cited by 4 | Viewed by 1778

Abstract

Background: Conventional bike sharing systems are frequently adding electric bicycles. A major question now arises: Does the bike sharing system have a sufficient number of ebikes available, and are there customers who prefer to use an ebike even though none are available? Methods: [...] Read more.

Background: Conventional bike sharing systems are frequently adding electric bicycles. A major question now arises: Does the bike sharing system have a sufficient number of ebikes available, and are there customers who prefer to use an ebike even though none are available? Methods: Trip data from three different bike sharing systems (Indego in Philadelphia, Santander Cycles in London, and Metro in Los Angeles and Austin) have been used in this study. To determine if an ebike was available at the station when a customer departed, an algorithm was created. Using only those trips that departed while an ebike was available, a random forest classifier and deep neural network classifier were used to predict whether the trip was completed with an ebike or not. These models were used to predict the potential demand for ebikes at times when no ebikes were available. Results: For the system with the highest prediction accuracy, Santander Cycles in London, between 21% and 27% of the trips were predicted to have used an ebike if one had been available. The most important features were temperature, distance, wind speed, and altitude difference. Conclusion: The prediction methods can help bike sharing operators to estimate the current demand for ebikes. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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19 pages, 6449 KiB

Open AccessArticle

Integrated Variable Speed Limits and User Information Strategy

by Ernesto Cipriani, Lorenzo Giannantoni and Livia Mannini

Sustainability 2023, 15(14), 10954; https://doi.org/10.3390/su151410954 - 12 Jul 2023

Viewed by 1068

Abstract

This paper deals with the study of variable speed limits (VSLs) for traffic control and their integration with user information strategies. As few studies have addressed the integrated VSL and user information strategy, we focus on comparing the adoption of the latter with [...] Read more.

This paper deals with the study of variable speed limits (VSLs) for traffic control and their integration with user information strategies. As few studies have addressed the integrated VSL and user information strategy, we focus on comparing the adoption of the latter with the VSL alone strategy application and the no-control case, highlighting the benefits the integration brings. The integrated strategy is able to smooth the severity of congestion, shifting its occurrence in a section of the mainstream mostly suited to vehicle accumulation. An application on a real network is carried out. The traffic congestion conditions along the real highway are simulated by means of Dynameq simulation software and the METANET macroscopic model. The VSLs are applied in a control area aiming to evaluate the potential and the limitations of the strategy on a real network as well as the integration of variable speed limits and user information strategies. Two different cases of road congestion caused by the presence of on-ramps are studied. Results show that the integration of the two strategies leads to a redistribution of flows, achieving a reduction in the total travel time spent in the network and an increase in the traveled distances, i.e., reducing the overall network time despite the increase in assigned flows. However, an integrated strategy requires adequate transportation supply and mainly crossing demand. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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10 pages, 10055 KiB

Open AccessArticle

Investigating the Effects of Automated Vehicles on Large Urban Road Networks: Some Evidence from Rome

by Umberto Crisalli, Andrea Gemma and Marco Petrelli

Sustainability 2023, 15(13), 10714; https://doi.org/10.3390/su151310714 - 7 Jul 2023

Cited by 1 | Viewed by 909

Abstract

This paper explores the possibility of applying simulation models formalized in the macrosimulation approach to predict the effects from the presence of automated vehicles in our cities. It is based on the use of a robust equilibrium assignment model allowing us to obtain [...] Read more.

This paper explores the possibility of applying simulation models formalized in the macrosimulation approach to predict the effects from the presence of automated vehicles in our cities. It is based on the use of a robust equilibrium assignment model allowing us to obtain multiclass traffic flows, including automated vehicles (AVs) and conventional ones (CVs) on large real-sized road networks. This modelling framework has been successfully applied to the road network of the metropolitan area of Rome, allowing us to assess the effects of AVs in future traffic at increasing penetration rates and the effects of possible transport policies involving AVs. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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19 pages, 1472 KiB

Open AccessArticle

Performances and Environmental Impacts of Connected and Autonomous Vehicles for Different Mixed-Traffic Scenarios

by Andrea Gemma, Tina Onorato and Stefano Carrese

Sustainability 2023, 15(13), 10146; https://doi.org/10.3390/su151310146 - 26 Jun 2023

Cited by 2 | Viewed by 1510

Abstract

As the transition towards connected and autonomous vehicles gradually happens, different phases with CAVs and human-driven vehicles sharing the same network will occur. This paper’s purpose is to increase the knowledge of these mixed situations, studying the impacts of an increasing number of [...] Read more.

As the transition towards connected and autonomous vehicles gradually happens, different phases with CAVs and human-driven vehicles sharing the same network will occur. This paper’s purpose is to increase the knowledge of these mixed situations, studying the impacts of an increasing number of CAVs within the vehicle fleet on road capacity, travel time savings and energy consumption, providing new insights into the debate that is still open. The methodology focused on a microsimulation-based approach on an urban motorway in the city of Rome. Some of the outcomes from simulations, run with the software PTV Vissim^TM 21, were used to analyse variations in general performances of the transportation system, whereas the remaining results were fed into the emission model COPERT for assessing the impacts of CAV penetration on the energy consumption of the fleet. Results show how, in congested cases, appreciable improvements can be recorded in terms of road capacity, mean speeds, and environmental impacts, while in lower-congested situations, any enhancement in traffic fluidification counteracts the environmental performances of the whole system. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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16 pages, 6573 KiB

Open AccessArticle

Motorway Traffic Emissions Estimation through Stochastic Fundamental Diagram

by Andrea Gemma, Orlando Giannattasio and Livia Mannini

Sustainability 2023, 15(13), 9871; https://doi.org/10.3390/su15139871 - 21 Jun 2023

Cited by 1 | Viewed by 993

Abstract

Travel time, or, more generally, level of service, has always been considered the main parameter with which to design roads, particularly in extra-urban areas where geometries and policies, such as speed limits, play a key role in the performance achieved. Unfortunately, this type [...] Read more.

Travel time, or, more generally, level of service, has always been considered the main parameter with which to design roads, particularly in extra-urban areas where geometries and policies, such as speed limits, play a key role in the performance achieved. Unfortunately, this type of approach does not consider the impact on emissions that is obtained when only performance-based goals are pursued. The paper deals with the analysis of the impact on emissions and fuel consumption under different traffic conditions, and we present a new methodology for emission estimation based on the stochastic formulation of the fundamental diagram in a highway environment. The proposed methodology estimates the emissions using a stochastic adaptation of the CORINAIR methodology based on COPERT software on both specific vehicle types and the average Italian vehicle fleet. As expected, due to the convexity of the emission function, accounting for speed dispersion leads to an increase in energy consumption and emissions. Tests show that the stochastic component can lead to an increase in the emission estimation up to 5.5% and, therefore, it should be considered. The methodology has been applied by means of real trajectories, and the results of the application show that performance optimization strategies can contrast with sustainability and emission reduction policies. Results show that for some vehicular classes, emissions or fuel consumption are highly dependent on speed, with different proportionalities. In all cases, the minimum consumption is obtained at speeds ranging from 70 to 90 km/h. The analysis of the curves shows that an increase in speeds, even to reach low speeds, generally leads to an increase in energy consumption and emissions per kilometer traveled and, therefore, is independent of the decrease in travel time. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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14 pages, 1064 KiB

Open AccessArticle

MaaS Adoption and Sustainability for Systematic Trips: Estimation of Environmental Impacts in a Medium-Sized City

by Riccardo Ceccato, Andrea Baldassa, Federico Orsini, Riccardo Rossi and Massimiliano Gastaldi

Sustainability 2023, 15(11), 8690; https://doi.org/10.3390/su15118690 - 27 May 2023

Cited by 1 | Viewed by 1634

Abstract

Mobility as a Service (MaaS) is often seen as a promising solution to address societal and environmental challenges. Despite the importance of quantifying its potential benefits, few previous works have focused on the impacts on the environment, and all of them considered large [...] Read more.

Mobility as a Service (MaaS) is often seen as a promising solution to address societal and environmental challenges. Despite the importance of quantifying its potential benefits, few previous works have focused on the impacts on the environment, and all of them considered large cities. This study aims to forecast the diffusion of MaaS in a medium-sized city and quantify the consequent reduction in pollutant emissions for commuting trips. Answers from a mobility survey administered to employees of the Municipality of Padua (Italy) were used to calibrate a model predicting MaaS adoption, which was applied to real working trips to estimate daily vehicle emissions savings in future scenarios with different MaaS bundles. The results indicated that the opportunity to have multimodal mobility options providing door-to-door travel is a fundamental element to ensure wide MaaS diffusion. Furthermore, public transport was confirmed to be the backbone of such a system. Compared to the current scenario, we observed up to a 41% reduction in pollutant emissions. The analysis pointed out that MaaS adoption is highly dependent on the characteristics of the proposed bundles, thus highlighting the importance of a proper design of the service and ex ante evaluation of emission savings. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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16 pages, 2111 KiB

Open AccessArticle

Connected Vehicles and Digital Infrastructures: A Framework for Assessing the Port Efficiency

by Orlando Marco Belcore, Massimo Di Gangi and Antonio Polimeni

Sustainability 2023, 15(10), 8168; https://doi.org/10.3390/su15108168 - 17 May 2023

Cited by 10 | Viewed by 2106

Abstract

In logistics and freight distribution, scheduling and cost efficiency are two crucial issues for transportation companies that look with favour at the innovation introduced by Intelligent Transportation Systems (ITS). Moreover, an infrastructure level of service, safety and environmental defence are important for planners [...] Read more.

In logistics and freight distribution, scheduling and cost efficiency are two crucial issues for transportation companies that look with favour at the innovation introduced by Intelligent Transportation Systems (ITS). Moreover, an infrastructure level of service, safety and environmental defence are important for planners and public administrations. In this sense, terminal capacity and landside operations at the maritime infrastructure represent an interesting task for the community. Thus, this paper contributes to the research by: (i) proposing a generic framework for the integration of autonomous and connected vehicles with physical infrastructures; (ii) evaluating the opportunity to manage traffic arrivals according to vehicles’ priority and testing the effects of the introduction of a buffer zone outside the maritime port; (iii) improving efficiency and security within the terminal area by reducing waiting time and avoiding interference between flows. Moreover, the proposal for a discrete-event simulation model to assess terminal capacity in a ro-ro terminal is presented. Therefore, the paper contributes to some critical aspects towards sustainable development. First, regarding policy measures and actions, it proposes a valuable tool to assess what-if scenarios. Secondly, it represents a step forward in the process of smart corridor design for freight vehicles; in fact, it proposes a tool for managing landside operations at maritime ports and focuses on intervention in solving specific barriers and bottlenecks for freight who cross a ro-ro terminal daily. Furthermore, it offers a viable solution for managing connected vehicles in a context where full automation still needs to be achieved. The results evidenced the framework’s capability to deal with the traffic demand, thus improving the efficiency of the terminal landside operations. Full article

(This article belongs to the Special Issue Looking Back, Looking Ahead: Vehicle Sharing and Sustainability)

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