Current Travel Research Articles

Simulation of Shared Autonomous Vehicles Operations with Relocation Considering External Traffic: Case Study of Brussels

Simulation studies on Shared Autonomous Vehicles (SAVs) could offer several insights to transport policymakers about future mobility. Case studies using the agent-based approach have recently emerged worldwide to test the impacts of SAVs on local networks. However, as the most densely populated area in Belgium, a relevant SAV study for Brussels is currently lacking. In this paper, we have simulated the impacts of substituting Brussels private car trips for people who either only travel in Brussels or do not travel to external places by car. The simulation was carried out with various SAV fleet sizes implementing vehicle relocation strategy. This paper describes how we transferred certain car trips to SAVs, and the respective SAV parameters used for simulation. The results suggest that under a 10% current travel demand, if all current studied drivers groups are willing to carpool as long as the additional travel times do not exceed a certain threshold, 1000 SAVs will be sufficient to replace these car trips in Brussels with the average daily request waiting time of around 5 minutes. By deploying SAVs with the proposed operational scheme, agents’ overall travel time and traffic congestion in Brussels can also be significantly reduced.

Emerging trends in household travel survey programs

Transportation planners use household travel surveys to understand travel behavior, whether to develop forecasts of travel activity using travel demand or simulation models, to analyze personal motivations that drive the decision to travel, to identify users of existing transportation infrastructure and services, or to determine responsiveness to available or future travel options. Large urban area transportation planning organizations are faced with making decisions on their next household travel surveying effort to meet growing data needs. The New York Metropolitan Transportation Planning Council (NYMTC) has focused attention on surveying options, including conducting a pilot study to evaluate the ability to collect household travel data using a smartphone app. This research reviews current travel surveying strategies aimed at improving timeliness and accuracy, while reducing participant burden (e.g., using smartphone technologies). It also includes a vision for a long-term data program, facilitated by the establishment of a regional Community of Practice (CoP) to support multi-agency data collection efforts.

A systematic literature review of Mobility as a Service: Examining the socio-technical factors in MaaS adoption and bundling packages

Mobility as a Service (MaaS) has been gaining popularity as a result of massive information and communication technology development in the transport sector. Studies examining mobility bundles and the factors behind their uptake have been published in recent years. Current paper provides a systematic literature review focusing on the socio-technical factors related to the adoption of MaaS and the creation of mobility packages. First, several methods, such as data collection, experimental design, and modeling techniques are studied to examine user preferences toward MaaS. This is followed by an analysis including socio-demographic variables, travel characteristics, psychological factors, and built environment variables. Afterward, the creation process of mobility packages is reviewed, where the included transport modes in the bundles are analyzed. Furthermore, the subscription options and add-ons are discussed, such as parking, dining, food delivery, and a high service guarantee. Based on the analysis of 29 relevant articles, socio-demographic factors show inconsistency regarding their impact on user preferences, while travel pattern variables are found to be more solid. Mobility packages are mainly tailored using current travel pattern data. The review reveals some less included factors as well as methodological gaps in the literature. Finally, directions for future studies are suggested, including using revealed preference data, considering the built environment factors, expanding the study location, and examining new potential user groups of MaaS adopters.

Experimental study of soil responses around a pipeline in a sandy seabed under wave-current load

Wave and current coexist widely in the oceans. Ever-changing wave characteristics, such as height and length, have a significant influence on the dynamic response within the seabed soil due to the presence of currents. Some aspects of wave, seabed and pipeline interactions have been widely investigated over past years, incorporating both experimental and numerical approaches. However, previous studies on seabed dynamic response around pipelines have mainly focused on cases with wave loading. In this experimental laboratory study, the current loading and diverse backfill conditions which commonly occur far offshore are discussed in depth. It is found that when subjected to the combined wave and current loads, the response of the seabed around a pipeline is more complex than that subjected to pure wave loading as current velocity and propagation direction would significantly change the wave characteristics as well as seabed response. Most notably when comparing with the pure wave loading, the pore pressure amplitude and its attenuation rate within the seabed increases when current and wave travel in the same direction. This could increase the possibility of liquefaction around the pipeline. When current travels in opposing direction to the wave, the effect of current on the decrease of pore pressure and its attenuation rate is more significant than that of the co-current actions. This means that the counter-current will reduce the probability of soil liquefaction.

Residency and worker status identification based on mobile device location data

Mobile device location data (MDLD) have been widely recognized for their rich human mobility information and thus considered as a supplementary data source for the current travel data bank consisting of travel survey data and traffic monitoring data. However, the lack of ground truth information about the device owners raises concern about the biases and representativeness of the nonprobability MDLD sample and significantly limits the applications of MDLD. This paper focuses on identifying two important socio-demographic characteristics for the MDLD sample devices: residency and worker status, including four worker types (normal commuters, professional drivers, mobility-for-work workers, and nonworkers/home-based workers). Based on the spatial–temporal patterns of location sightings and derived trips from MDLD, a comprehensive imputation framework is proposed with parameters calibrated against public domain ground truth data. A national-level case study in the U.S. based on a commercial MDLD dataset further evaluates the performances of the proposed heuristic rules. The multi-level validation results indicate a satisfying match against the ground truth data and prove the effectiveness of the proposed methods. As one of the earliest efforts to identify the residency and worker status information for a large-scale national-level MDLD dataset, mobile workers—including professional drivers and mobility-for-work workers—are also identified from MDLD for the first time.

Attitude changes, modelling travel behaviour, and ex ante project evaluations

The literature has increasingly recognized that people’s attitudes can change for many reasons. This paper argues that attitude changes can have important implications for modelling travel behaviour and ex ante evaluations of candidate policy options. Limiting ourselves to the transport system and the built environment, we discuss why attitudes could change, how these changes are not addressed in current aggregate travel behaviour models, mainly the four step model, and how they could influence the assessment of candidate policy options. We suggest related avenues for future research. The core point we want to make is that attitude changes are not included in aggregate models, which leads to an underestimation of the impacts (often: benefits) of unconventional transport policy options.

Density-driven exchange flow propagating over an array of densified obstacles

The evolution of bottom-propagating gravity currents with the presence of an array of densified obstacles submerged in a channel is investigated using large-eddy simulations. Our attention is particularly focused on the flow transition of gravity currents over rough surfaces with extra resistance that provokes significant dissipative processes. Two geometric parameters of the roughness elements, namely, the submergence ratio of the obstacle D/H and the gap-spacing ratio λ/D between obstacles, govern their kinematic and dynamic effects on the propagation of gravity currents. Physically, D/H plays a significant role in the control of the current diversion, and λ/D regulates the flow pathway of gravity current propagation. The integrated measures show that two distinct flow morphologies are identified. For a low submergence ratio (D/H<0.15), an overtopping flow is formed in which the gravity current travels on the top of the array and undergoes an inconspicuous loss of buoyancy, subject to minimal vertical convective instability interacting with the underlying ambient fluid within the gap regions. For a sufficiently high submergence ratio (D/H≥0.15) and a certain gap spacing (2≤λ/D<4), an overrunning flow is formed in which the current rapidly decelerates to a buoyancy–inertia state and then transitions to a drag-dominated state with a gain in excessive drag, in which the front velocity is proportional to t−0.5. However, the simulation results show a turning point toward an increase in the gap spacing as λ/D≥4, that the maximum drag acting on the gravity current is measured when it impinges on the second obstacle of an array, and that the drag coefficient goes up by 10%–40%, depending on D/H. The propagation of the gravity current does not show a higher sensitivity to the retarding effect instead. Meanwhile, the promotion of energy conversion occurs because of the gravity current encountering the continuous climbing and plunging flow behavior between two adjacent obstacles in regular motions.

Propagation Speed of the Frontal Head Through Lock-Exchange Density Current in Cold Fresh Water: Simulations without the Effect of Back-reflected Waves

The behaviour of warm water discharged at 4\(^{\circ}\)C through lock-exchange in cold fresh water was investigated numerically, fixing lock volume at the centre of the domain. This investigation as presented here is practical and can also enhance policy making towards the protection of the aquatic ecosystems. Though, the aim of this study is to better fathom and as well, gain more insight into such ows. Our results have shown a speedy movement of the lock volume at the centre of the domain with a leading head at two front on the oor which resulted in a hat shape within the first few time frame. Fluid movement in the second phase is independent of the back reflected waves. We were able to identify two regimes of ow with a stepwise decreasing velocity in the second phase. Our results have shown that velocity with which the current travels with in the second regime is higher within the first time frame as compared to those with the effect of back reflected waves. One major factor that is responsible for decrease in the velocity here is mixing. Previous results have also shown that the front velocities in the collapsing phase are independent of lock volume. But this seem not to be the same here because fluid movement in the first phase (regime) is not totally independent of the lock volume and its position here, where density difference is as a result of temperature. However, our scaling power laws here in the second phase show some variations with previous studies where we have effect of back reflected waves. But results in the collapsing phase here are in strong agreement with those in the first phase of our previous simulations with small lock volume. Generally, the spreading behaviour here is dependent on lock volume, barrier position, density difference and Reynolds number.

Investigating The Effect of Nickel Buttering on Corrosion Resistance

Cladding is usually employed for improving corrosion and/or abrasion resistance of a component. Buttering layer between clad layer and structural steel is also sometimes provided to promote bonding between the cladding and the substrate. The buttering layer may also give desired corrosion resistance. Nickel is known to be a common austenite stabilizer, and it is often put inside cladding, coating, buttering, etc. to enhance hardness and corrosion protection of steel. In the current investigation, 316 austenitic stainless steel is deposited over nickel plated medium carbon steel substrate with the help of metal active gas welding. Nickel is accumulated on medium carbon steel by electroplating to act as a buttering layer. Welding current and torch travel speed, two important process parameters are varied with constant arc voltage to develop different values of heat input. Accelerated corrosion test in chloride atmosphere is done on ground and polished clad surface. Corrosion rate is observed to be decreased significantly for all the clad samples relative to the base material. However, no clear trend of corrosion rate against increment in heat input is found for reporting, but corrosion rate shows a typical pattern with the variation of heat input.

Exploring Users’ Preferences for Automated Minibuses and Their Service Type: A Stated Choice Experiment in the Netherlands

In this paper, we study the deployment potential of automated minibuses (AmBs) on the first-mile part of public transport (PT) trips or short (sub)urban commutes by comparing “regular” (fixed route and fixed schedule) and “flexible” (door-to-door and on-demand) service types. For reaching that goal, we run a stated choice experiment in the Netherlands. The participants have assessed the referred two AmB alternatives compared to their current travel mode (car, PT, or active modes (AM) – bicycle and walking) used as the main mode for unimodal travellers or as access travel mode to transit lines for multimodal travellers. The results of a joint mixed logit model estimation based on data obtained from Dutch travellers show that there are similarities and differences in the preferences for the AmBs service type within and between the segments of travellers (car, PT, and AM) and that these are mostly in instrumental variables (cost and time) and attitudes. Current PT users prefer the flexible service to regular service based on their perception of in-vehicle travel time and waiting time, while current users of car and AM do not show a difference in preference between the two services concerning these variables. Moreover, their perception of in-vehicle travel time and waiting time is not significantly different from PT users’ perception of those variables in the regular service. This may mean that for non-PT users (car and AM), AmB’s flexibility of door-to-door transport is not seen as offering a significant advantage over what they think about public transport. When looking at the preferences of potential users explained by underlying psychological factors, we conclude that a positive attitude towards riding in AmBs is a significant factor in all three segments of travellers. Trust, usefulness, and enjoyment in using AmBs are important prerequisites for car and PT users to choose either service type. The experience with technology positively influences the preferences of current PT users for both AmB services.

Babymoon Tourism: Co-Creating Well-Being for Traveling Mothers

This article aims to provide insight into how babymoon tourism can contribute to well-being by using a multimethod approach, combining autoethnography and netnography. The findings show that mothers-to-be experience well-being derived from co-creation and meaning. Participation in activities and everyday-like events at the destination can lead to happiness and improved quality of life. Self-development, empowerment, interpersonal interactions, and engagement with local culture all inspire well-being. In contrast, destinations’ representations of babymoon tourism focus on physical facilities, where culture and co-creation are absent in the realization of well-being. Viewing co-creation of well-being through a cultural interaction lens suggests an untapped potential for tourism businesses and could be a way forward for promoting babymoons. The study makes theoretical and practical contributions. Its original methodological approach, namely an autoethnographic narrative of babymoon tourism, could lower the threshold for conducting autoethnographic studies in current travel research, and encourage further studies of babymoon tourism.

The substitution of short-haul flights with rail services in German air travel markets: A quantitative analysis

In recent years, a ban on short-haul flights for which alternative, more environmentally friendly transportation is available has been on European regulatory agendas, particularly in countries like Germany, with its well-developed high-speed rail (HSR) and a dense network of low-cost, point-to-point airline traffic. This study aims to quantify the potential impact on CO2 emissions of substituting short-haul flights with rail frequencies in 87 German air travel corridors. Using OAG data on passenger bookings and airline schedules for 2019, as well as current rail travel times, we determine the target flights by looking at the actual proportion of connecting passengers per frequency. We estimate a potential reduction in CO2 emissions of between 2.7% and 22%, depending on how strict the flight substitution is. However, the social benefits of those carbon emissions might fall short of the travel time losses experienced by the passengers. Increased investment to improve rail speeds and intermodal accessibility appears necessary before the substitution policies can be implemented.

Damping coefficient by long waves—viscoelastic mud–current interaction

In this work, we study the damping of long linear waves propagating on a thin mud layer, which obeys a viscoelastic behavior, in the presence of a marine current; two cases are considered: (1) a current traveling in an opposite way to the wave propagation and (2) in the same way to the wave propagation. We obtain an asymptotic solution to the dimensionless governing equations, which allows identifying the competition between the different mechanisms involved to gain insight into the physics by which coastal mud responds to water waves. To determine the shear stresses into the viscoelastic mud, we have used the well-known Maxwell rheological model. At the interface water–mud, we assume the presence of a small Stokes' layer, and this condition allows us to consider the continuity of shear stresses and velocities at the interface. The effects of the mud physical parameters as well as the hydrodynamics impact of the water waves on the damping coefficient, fluid velocities, and shear stresses and on the free surface elevation are analyzed. The results show that the maximum value of the damping coefficient occurs when the mud thickness is of the same order of magnitude as the Stokes' layer and for increments of the current magnitude traveling in an opposite way to the wave propagation. The asymptotic solution is compared with solutions reported in the specialized literature and the results adjust properly.

Orientation and Mobility Assessments for Children and Youths With Visual Impairments: How, Why, When, and Where?

Introduction: This study analyzed survey responses from 114 orientation and mobility (O&M) specialists regarding the content and procedures they used in completing O&M assessments. Methods: O&M specialists completed an online survey in 2020 on their assessment practices for children and youths who are visually impaired. Results: Over 85% of participants identified that they interview the student, parent, classroom teacher, and teacher of students with visual impairments as part of the assessment. The only visual skills addressed by at least 80% of participants were depth perception, distance acuity, scanning, and peripheral visual fields. Students without additional disabilities in kindergarten through 12th grade were more likely to be taught the two-point touch cane technique when compared to students with additional disabilities, who were more likely to be taught constant contact. Discussion: Participants identified that O&M assessments for students in 9th–12th grade were more likely to focus on skills that would be needed for employment or post-secondary education or both, such as the use of public transportation. For students with additional disabilities or children under the age of five years, participants were more likely to conduct assessments focused on safety and immediate needs and environments. Implications for Practitioners: Appropriate O&M assessments need to be conducted in natural environments that provide equal challenges to the environments where students need to travel. O&M specialists must adapt the assessment content and procedures to address the current and future travel needs of all students with visual impairments.

Global monkeypox outbreak 2022: First case series in Singapore

Monkeypox is a global health emergency. Prior to 2022, there were few reports of monkeypox outside of endemic countries, which were mostly travel-related. Since May 2022, an exponential increase in monkeypox infections in previously non-endemic countries has been reported. Unlike previous outbreaks of monkeypox, which were zoonotically transmitted and presented with generalised vesicular eruptions after prodromal symptoms, cases of the current outbreak feature significant travel and sexual history, and atypical localised genital eruptions with unpredictable onset relative to viral prodrome-like symptoms. We summarise the 15 Singapore cases reported to date as of August 2022, and highlight salient clinical clues that may aid physicians in narrowing the broad differential diagnosis of an acute vesicular genital eruption. Although research into vaccination and antiviral strategies is ongoing, monkeypox is currently conservatively managed. Clinical vigilance and a high index of suspicion are required to facilitate early detection and isolation of cases to contain transmission in Singapore.

Improving future travel demand projections: a pathway with an open science interdisciplinary approach

Transport accounts for 24% of global CO2 emissions from fossil fuels. Governments face challenges in developing feasible and equitable mitigation strategies to reduce energy consumption and manage the transition to low-carbon transport systems. To meet the local and global transport emission reduction targets, policymakers need more realistic/sophisticated future projections of transport demand to better understand the speed and depth of the actions required to mitigate greenhouse gas emissions. In this paper, we argue that the lack of access to high-quality data on the current and historical travel demand and interdisciplinary research hinders transport planning and sustainable transitions toward low-carbon transport futures. We call for a greater interdisciplinary collaboration agenda across open data, data science, behaviour modelling, and policy analysis. These advancemets can reduce some of the major uncertainties and contribute to evidence-based solutions toward improving the sustainability performance of future transport systems. The paper also points to some needed efforts and directions to provide robust insights to policymakers. We provide examples of how these efforts could benefit from the International Transport Energy Modeling Open Data project and open science interdisciplinary collaborations.

Tourist Attraction Recommendation Method Based on Megadata and Artificial Intelligence Algorithm

As China’s economy continues to grow of informational technology and mobile Internet industry, the online tourism industry has received more and more extensive attention and use. However, as an emerging industry, users often need to spend a lot of time to choose travel services that match their needs because of the complex amount of relevant information. Under such circumstances, this paper studied the recommendation method in travel platform. First, the big data is used to extract user data. Secondly, the current online travel business recommendation for users has the problem of low accuracy. The reason is that the services provided are still in traditional recommendation algorithm. In this paper, the Bayesian network is used to evaluate the user’s attribute preference and generate a data model, using effective methods in artificial intelligence algorithms to improve collaborative filtering algorithms and finally generate hybrid recommendation algorithms. Compared with the traditional recommendation method, the experimental results showed that the research can improve the recommendation accuracy of tourist attractions by 6.55%, increase the user’s satisfaction for the platform, and enhance the visit rate and retention rate of the tourist attraction recommendation platform.

Why Mean Potential Vorticity Cannot Be Materially Conserved in the Eddying Southern Ocean

Abstract Downstream of Drake Passage, the Antarctic Circumpolar Current (ACC) veers abruptly northward along the continental slope of South America. This spins down the ACC, akin to the western boundary currents of ocean gyres. During this northward excursion, the mean potential vorticity (PV) increases dramatically (decreases in magnitude) by up to a factor of 2 along mean geostrophic streamlines on middepth buoyancy surfaces. This increase is driven by drag near the continental slope, or by breaking eddies further offshore, and is balanced by a remarkably steady, eddy-driven decrease of mean PV along these northern circumpolar streamlines in the open ocean. We show how two related eddy processes that are fundamental to ACC dynamics—poleward buoyancy fluxes and downward fluxes of eastward momentum—are also concomitant with materially forcing PV to increase on the northern flank of a jet at middepth, and decrease on the southern flank. For eddies to drive the required mean PV decrease along northern streamlines, the ACC merges with the subtropical gyres to the north, so these streamlines inhabit the southern flanks of the combined ACC–gyre jets. We support these ideas by analyzing the time-mean PV and its budget along time-mean geostrophic streamlines in the Southern Ocean State Estimate. Our averaging formalism is Eulerian, to match the model’s numerics. The thickness-weighted average is preferable, but its PV budget cannot be balanced using Eulerian 5-day averaged diagnostics, primarily because the z-level buoyancy and continuity equations’ delicate balances are destroyed upon transformation into the buoyancy-coordinate thickness equation. Significance Statement The Antarctic Circumpolar Current is the world’s largest ocean current and a key controller of Earth’s climate. As the westerly winds that drive this current shift poleward under global warming, it is vital to know whether the current will follow. To begin addressing this, we study the current’s fundamental dynamics, and constraints, under present-day conditions. By analyzing angular momentum and stratification together, we show that the current is weakened near boundaries and strengthened by eddies elsewhere. The strengthening effects of eddies are isolated to the current by merging the current with oceanic gyres to the north. This gives a new perspective on why the current travels so far northward alongside South America, and may provide dynamical constraints on future changes.

Editorial: academic peer reviewers – The good, bad, and the ugly

Editorial: academic peer reviewers – The good, bad, and the ugly

Development of Marketing Mix in Tourism With Technology Acceptance Model (TAM) in the Tourist Area of Kerinci Regency

The current travel trends are increasingly inclined to the “back to nature” concept. In Kerinci Regency, Indonesia, tourism is expected to contribute to the area’s economic growth. The present study was conducted to analyze the factors in the marketing mix in tourism that influence the perceived ease of use of the Technology Acceptance Model (TAM) in using travel applications. The study uses primary data obtained or collected independently directly from the source through a questionnaire and interviews with 400 respondents. The TAM was tested using SEM (Structural Equation modeling) with Amos 25. The results showed that the variable price and people had a significant effect on the TAM. Additionally, the TAM influences people’s intention to use travel applications.
 Keywords: marketing mix tourism, Technology Acceptance Model (TAM), intention to use travel application