Transportation Research Part A-Policy and Practice最新文献

As a type of critical infrastructure, multimodal transportation networks are susceptible to disturbances from natural disasters and intentional attacks. Resilience reflects the performance of a multimodal transportation network after suffering from a disaster, and the failure of this network influences the public life and induces economic losses. This research aims to evaluate and improve the resilience of post-disaster multimodal intercity transportation networks to mitigate negative influences of disturbances. A comprehensive resilience performance metric, accounting for influences on unserved demand and adaptation of served demand was proposed to evaluate the resilience of multimodal transportation networks. The multimodal traffic assignment model was developed to derive the components of this comprehensive performance metric, integrating user equilibrium and modal split, while considering the capacity upper bound of some links. A route-based link recovery sequence was also proposed to improve network resilience, taking into account interdependencies and utilization of damaged links. The operational measure of capacity enlargement of functioning links was adopted to supplement the recovery sequence. The proposed resilience evaluation and improvement method was applied to a multimodal transportation network, namely, the constituent road, rail, and air networks in the Beijing–Tianjin–Hebei–Shandong region. Results show that the proposed route-based strategy outperforms volume-based, betweenness-based, and random strategies in enhancing resilience. Capacity enlargement of functioning links can further improve resilience by accommodating more affected demand, particularly effectively in scenarios characterized by inefficient repair sequences, higher fixed demand and a larger punishment multiplier. These findings highlight the interdependencies of links in establishing the recovery sequence, capacity enlargement in challenging scenarios, and enhanced availability and convenience of transportation modes to promote multimodal network resilience after a disruption.

Walking, as a form of active travel, has played a significant role in facilitating sustainable transport and the development of the built environment. A growing number of studies have examined the relationships between the built environment and active travel trips around transit stations. However, travellers’ propensity to walk to transit stops and their travel satisfaction with doing so, particularly for first-mile trips, and its relationship with the built environment, in developing countries, have so far received little attention in the literature. Thus, this paper examines the nonlinear influences of landscape configurations, walking access to transit services and the interactions between them on travel satisfaction. Gradient boosting decision tree models are used to control for trip attributes and factors related to the built environment both in residential areas and business/commercial districts where a lot of transit stations are located. We combine street view data and individual survey data for the Beijing metropolitan area to document that improving walking access to transit services has significant effects on travel satisfaction. The results show that landscape configurations tend to have nonlinear associations with walking access to transit services as well as having pronounced interaction effects on travel satisfaction. The findings of this study demonstrate the importance of planning the spatial placement of stations to make them more convenient and improve people’s travel satisfaction with first-mile journeys made on foot.

The link between transport disadvantage and social exclusion is now firmly-established. Smartphones emerge as an integral part of daily life with a strong potential to influence this link by improving people’s capacity to access transport information and availability, and enabling direct connections with others in society. However, the role of smartphone use for transport purposes in influencing people’s daily mobility and quality of life remains under-studied, in part impeding a more concrete discourse on how it can be better evaluated and considered in policymaking. This study seeks to shed light on the above issue through probing into the interrelationships among smartphone use, transport disadvantage and social inclusion, and their relation to subjective well-being. Using Beijing as a case study, we tested a series of hypotheses through structural equation models (SEM). Our findings highlighted potentially bidirectional interactions between smartphone use and transport disadvantage. By and large, smartphone use for both normal purposes and new modes can help mitigate transport disadvantage, and this may further stimulate more smartphone use as a proactive solution. Furthermore, the link between smartphone use for new modes and transport cost, and their consequent effect on social inclusion and subjective well-being were found to vary between low- and high-income groups. Findings suggest that smartphones and smart apps should be carefully integrated in policymaking to reduce the risk for people of being socially excluded due to a lack of transport options and improve subjective well-being.

Frequent and dramatic container shipping market turbulence has caused concerns among shipping stakeholders and governments around the world. While exogenous shocks such as economic recessions and pandemics are attributed to such turbulence, the changing shipping market structure with the formation of shipping alliances could also play a moderating role. The US government has begun to stipulate stricter policies that restrict shipping alliance development and aim to stabilize the freight rate. In this paper, we examine how shipping alliances can moderate freight rate volatility in the container shipping market. An analytical economic model is first derived to generate theoretical predictions, and an empirical study is then conducted by using real-world shipping market data to verify the theoretical predictions. Specifically, our analytical results suggest that shipping alliances can aggravate the volatility of freight rates when the market shock is from the demand side while alleviating the volatility caused from the supply side. Moreover, shipping alliances always lead to lower volatility in port charges. When the shipping demand (or shipping fuel price, respectively) is stochastic, the alliance-induced cost savings through economies of scale have no impact (or increases, respectively) on differences in volatility in both port charges and shipping freights with and without a shipping alliance. On the basis of panel data of 10 selected Chinese major container shipping routes from 2010 to 2021, a panel data regression model with two-way fixed effects (TWFE) is estimated. The empirical results confirm our analytical conclusions. We construct an integrated economic model to reveal that shipping alliances can affect market risk in a rather implicit way, i.e., through freight rate volatility, which has not been explored. Moreover, our empirical study results support the theoretical results and accurately quantify the impacts of shipping alliances on main international container shipping routes, thereby providing related policy implications for regulators.

Amongst the most popular alternatives to the current car-dominant planning model to have emerged in recent times is the 15-minute City (15mC). The 15mC prioritises the notion of local living. It seeks to address the pressing challenges of urban life by promoting lifestyles largely independent of motorised travel modes by focusing on active mobility and proximity to essential amenities. Despite the popularity of this concept, a knowledge gap exists regarding the diverse range of international practical definitions, strategies, instruments, and implementation experiences, as well as the requirements for, and challenges involved in, operationalising the 15mC and related concepts.

Consequently, this paper seeks to conduct a comprehensive analysis of the implementation of 15-minute cities and associated practices worldwide by combining an extensive literature review of both academic and grey literature sources with an expert survey. This culminates in the creation of a classification typology for the 15mC, based on the diversity of contexts and practices found, and informed by the Diffusion of Innovations Theory (DOI). Almost one hundred cities were identified as either in the process of implementing or planning to implement the 15mC concept. A diverse assortment of associated practices was identified, ranging from supporting active mobility to repurposing car space for other uses, promoting mixed land use and densification, and encouraging citizen engagement, among others. However, most cities are in the initial stages of executing their 15mC strategies, with the majority of practices still in the planning phase.

Although cities worldwide have shown considerable interest in the 15mC concept, many have yet to embark on adopting comprehensive strategies or measures aimed at achieving more radical change, notably in areas such as logistics and governance.

Equipped with sophisticated, AI-based driver assistance systems, passenger cars are becoming increasingly intelligent. It seems that in a matter of a few years, fully autonomous vehicles will operate without any driver intervention. In this context, researchers are addressing the question of how fully automated vehicles should make decisions in critical situations. Should they spare the driver, children jumping out into the road or elderly people standing on the sidewalk? Projects such as MIT’s Moral Machine are investigating the preferences of people from different nations and cultures for ethical decision algorithms. Evaluations of these automated decisions and how the may impact consumer perception and well-being are still scarce. In our experimental study, participants experienced a simulator-based driving situation in a fully autonomous car, after which they were confronted with alternative scenarios requiring automated action by the car in a critical situation. We measured the emotional status and well-being of our test-persons (N=33) in those critical situations using facial expression recognition (FER), electroencephalography (EEG), and standardized questions. The results show that there are detectable differences between the scenarios with respect to emotions as well as subjective well-being and behavioral intentions in the test group’s responses to the questionnaire. Regarding FER and EEG, no statistically significant differences could be shown due to the small subsample.

This paper assesses the equity impacts of shared micromobility and investigates regulatory policies that improve transport equity and promote synergy between public transit and shared micromobility. We consider a multimodal transportation network, where a micromobility platform deploys docking stations and operates a fleet of micromobility vehicles to provide shared micromobility services and a public transit agency offers transit services over a transportation network. A market equilibrium model is developed to capture the intimate interactions among access and egress times of shared micromobility services, waiting times of transit services, the spatial distribution of docking stations, passenger demand, platform pricing and fleet sizing, vehicle repositioning and the micromobility platform profit. The platform decision problem is cast as a high-dimensional non-convex program. A solution method is proposed to efficiently compute the solution through problem reformulation and dimensionality reduction. Based on the proposed framework, we evaluate spatial equity in transport accessibility using the Gini index, and find that although shared micromobility improves overall transport accessibility, the benefits are not fairly distributed across different geographic zones, which leads to enlarged spatial inequity gaps after introducing shared micromobility. To promote transport equity, we investigate three policy directions: (a) to impose a vehicle density floor on shared micromobility; (b) to offer a subsidy on shared micromobility rides for first/last-mile connections; and (c) to promote collaboration between public transit and shared micromobility. We show that different regulatory policies have advantages and limitations. The minimum vehicle density requirement can simultaneously improve spatial equity and passengers’ surplus, but has limited equity improvements. In contrast, the subsidy on bundled services could significantly mitigate spatial inequity, but it hurts passengers and the platform profit. Compared to the other two policies, the transit-micromobility collaboration can lead to higher equity improvement, higher passenger surplus, while offering a guarantee on the platform profit, which turns out to be the most cost-effective approach. These insights are validated through realistic numerical studies for San Francisco.

This study investigates the influence of high-speed rail (HSR) station placements on urban economic activities within cities. Specifically, we assess their effects on government-driven new land supply and market-driven emerging economic activities. Using data from 2007 to 2017, our analysis encompasses 720 HSR stations across 319 Chinese cities, with a focus on remote stations situated in the peripheral counties. Our findings reveal that remote HSR stations typically function as new city subcenters. They consistently drive the expansion of both land supply and economic activities (distance effect) and draw them toward the quadrant surrounding the station (direction effect). However, the alignment between their impacts on land supply and economic activities varies based on the city characteristics. In cities experiencing population declines, remote HSR stations notably affect land supply but have a negligible influence on economic activities, leading to resource misallocation and an increased risk of ghost towns. Furthermore, better HSR accessibility and higher tertiary industry proportions can magnify the spatial spillover effects of HSR station location on both land supply and economic activities.

Electric vehicles (EVs) are considered a promising alternative to achieve a cleaner transportation sector. In the last decade, European countries have implemented financial incentive policies to boost EV adoption. This paper estimates the impacts of these policies on EV adoption in Europe using data from 30 countries from 2012 to 2021 and a multi-period difference-in-differences approach. Our results reveal that purchase incentive policies are associated with increased registrations of battery electric vehicles and plug-in hybrid vehicles, and that the effect holds over time. However, the magnitude and duration of these effects are more significant for battery electric vehicles. Ownership incentive policies do not contribute to EV registrations for either type. Further, the results suggest that policy impacts vary between countries with different levels of gross domestic product per capita and renewable energy consumption. These results contribute to the literature on evaluating financial incentive policies for EV adoption, enabling improved decision making by policymakers.

Evacuation during a catastrophic disaster is a crucial operation that needs to be appropriately managed and is of more importance when considering the elderly and people with disabilities. The uncertain and unpredictable nature of disasters can cause long-term repercussions, especially in traffic congestion. This study presents a mathematical model to formulate traffic balance for regular and assisted evacuation (that is, disabled and the elderly) whilst considering traffic congestion in evacuation clearance time by applying contraflow. A Branch and Price (B&P) related approach is developed to help solve the proposed model in large-size problems. The presented algorithm is applied to a case study of Australia’s 2013–14 bushfires in Gippsland, located in the eastern part of Victoria. A variation test is performed to evaluate the robustness of results generated by the developed model. Results indicate that the participation percentage of edges is different based on their location, capacity, and sustainability of blockage. The edges’ capacity influences the evacuated population most compared to route capacity and time window. The output of this approach enables authorities to improve the resilience of communities by making optimal strategic and operational decisions for enhancing an evacuation response as well as influencing appropriate policies.