Asian Transport Studies最新文献

Over ten years have passed since Japan Airlines (JAL) filed for bankruptcy. This paper treats how the Japanese government undertook the bailout in January 2010 and subsequent measures to facilitate competition between JAL and the other national air carrier, All Nippon Airways (ANA). After describing the bailout process and post-bailout measures regarding slot allocation at Haneda Airport, the paper assesses the impact of these government interventions on airline productivity. Although JAL's total factor productivity (TFP) plunged with bankruptcy, they managed to turn the business around and TFP rapidly recovered thereafter to exceed that of ANA. Regression Discontinuity (RD) design analysis shows evidence of positive impact of these government interventions on TFP growth rate of the two airlines. As of 2016, JAL and ANA's TFP figures are more-or-less equal. In Japan, a new era of competition of the two legacy air carriers has emerged.

When data are available from two time points—older data with a larger number of observations and more recent data with a smaller number of observations—then model updating is utilised to take advantage of the different merits of each data set. However, the author's previous study demonstrated that conventional model updating methods—transfer scaling, joint context estimation, Bayesian updating, and combined transfer estimation—were inferior to models using only the more recent data. The present study examines an updating method that the author calls an ‘updating function model’ in which the parameters are assumed to follow the functions of gross domestic product per capita. The present study demonstrates that the updating function model often produces statistically significantly better forecasts than models using only the more recent data. The study extends the applicability of the model updating to cases in which the more recent time point has more observations than the older time point.

Personal mobility vehicles (PMVs) are small and slow vehicles that are designed to move within relatively dense pedestrian traffic on sidewalks or shared-use paths. Although various types of PMVs have been developed recently, the requirements of PMV performance in various traffic conditions are yet to be discussed in depth. This study aims to evaluate the impact of geometry and traffic conditions on the safety of mixed traffic flow between pedestrians and standing-type PMVs using a traffic simulation model. As a surrogate safety measure, an objective risk index based on collision probability and collision intensity is proposed. The results of the traffic simulations showed that the objective risk was affected by sidewalk width, traffic demand, and PMV movement parameters. A linear regression model was estimated to explain the safety index as a function of these variables, and combinations of applicable settings for PMV–pedestrian mixed traffic flow in terms of safety are discussed.

This study analyzed the single-regime speed-density (v-k) relationships for urban expressways using high resolution Zen Traffic Data (ZTD) containing all vehicles’ trajectory data obtained using image sensing technology. The steady-state traffic data were extracted for varying spatiotemporal resolutions, followed by estimation of traffic flow parameters, namely, jam density, kinematic-wave-speed, and proportionality factor, a behavioral parameter, using empirical data. Functional and shape parameters were estimated using the Levenberg–Marquardt algorithm. Statistical metrics were used to assess the performance and model fitness in all categories of linear, exponential and logarithmic, and complex forms of v-k relationships for different resolutions. The theoretical analysis revealed that certain relationships satisfy all the static properties and that only one satisfies both the dynamic properties of traffic behavior. Highly parameterized forms had the lowest errors. However, the linear form of model developed by May and Keller has high application potential.

With the aging of the population, the number of elderly drivers is increasing. Elderly drivers tend to overestimate their driving abilities, despite their maneuvering skills and cognitive function worsening with aging. Therefore, understanding the driving behavior of older drivers is becoming increasingly important for assisting their safe driving. This research analyzes the characteristics of old drivers' driving behaviors by utilizing the GPS trajectory data collected by the driving recorders installed in their vehicles. The analysis conducted was from the perspectives of route choice, driving time, driving distance, risky driving event, and driving speed. Furthermore, a linear regression model was used to explore the influence of drivers’ socioeconomic attributes and travel behaviors on driving speed. The results show that older drivers prefer short-distance travel in the daytime and tend to have more risky driving behaviors with aging.

This study estimates the price elasticity of demand per airline route using a demand function and airfare function with Japanese data including the access and egress cost to clarify the relationship between airlines and railways by focusing on the travel time. The study also estimates the access and egress cost elasticity of demand per airline route to explore the effect of the access and egress cost on the demand. From the results of estimation, We conclude that reducing the total travel time would increase the airline demand and change the relationship between airlines and railways. Additionally, we consider that passengers would be more sensitive to the cost in the case that the average access and egress cost ratio exceeds 30% than in the case that the average ratio is under 30%.

Pedestrianization is often suggested as a means to revitalize downtown Cebu City. However, commercial establishments fear that the closure of main roads like Colon St to vehicle traffic will hurt their business rather than help. Studies in other countries point to many contextual factors that affect the outcomes of pedestrianization projects. This study reveals that improving walkways, though desirable, is not the most important intervention that will increase visitation to the area. Respondent pedestrians and commercial establishments gave priority to improving security and addressing urban environmental concerns such as cleanliness and flooding. If current clientele visit the area at least once more within a year, it is estimated that 30 million pesos and 31 million pesos in additional business revenue can be created for Colon St and Osmena Blvd respectively. This scale of benefit may help economically justify the needed interventions for improving the pedestrian environment in downtown Cebu City.

The 36-month taxi crash data include 41,538 taxi crash records distributed throughout 29 districts of Singapore (including Changi Airport), involving 16,933 taxis and 16,705 taxi drivers. We purposely use these data to analyze the impacts of nine influential factors on taxi crashes and give quantitative and practical suggestions on taxi driving safety. Our solid analysis shows that the maximum daily working time for a taxi driver is suggested to be less than 10 h for safety concerns because it could reduce the possible taxi crashes. In addition, the likelihood of taxi crashes in the daylight is the highest when compared to road conditions with streetlights or one without streetlights at all. We further use the random forest method to find the critical influential factors in blue and yellow taxi crashes. The relief and switcher modes are the two unique factors contributing to taxi crashes that are different from private car crashes. The findings of this study are of significant value for taxi operators and policymakers.

App-based ride hailing services (ABRHS) are becoming increasingly popular among masses in recent years. The assessment of customer's satisfaction with service quality of ride hailing services is essential for success of these services in the long run. Therefore, the current study aims to understand better the complexities of factors influencing the customer satisfaction and intentions towards app-based ride hailing services through the finding of a questionnaire study in Lahore, Pakistan. The collected data from 865 respondents were analyzed using exploratory factor analysis and structural model of traveler's satisfaction with the service quality was constructed. Structural Equation Modelling (SEM) also revealed that the commuter's overall satisfaction with service quality of app-based ride hailing service has positive impact on user's intentions to continue using services in future. The SEM further explained that overall satisfaction with the services mediates the relationship between service quality attributes including service & system attributes, service attraction attributes, network design attributes, and service reliability & professionalism attributes and commuter's intentions to continue using in the future. The further improvements in the quality attributes of app-based ride hailing services would enhance the traveler's overall satisfaction and their intentions to continuing using these services in the future.

The roadside rest area (RRA), called “Michi no eki” in Japanese, is a facility that provides comfortable rest and diverse services to road users through community initiatives. There are many RRAs developed since its first establishment in 1993. It is important to identify the RRAs and regions where a certain function is weak, so as to build more substantial RRAs in the future. In this research, we divided the RRA functions into four categories, rest, information, regional collaboration, and disaster prevention, and listed their evaluation items. By checking the performance of RRAs in terms of the four functions, we can evaluate whether their performance can be improved by sharing functions with or complementing neighboring RRAs. We then calculated the evaluation results. During the evaluation, we compared two types of cases: one where the RRA was evaluated alone and the other where overlay evaluation was performed. The latter considered the distance among RRAs so that a complementary relationship with others could be expressed. Furthermore, we devised a method to calculate the impact of RRAs on an area and evaluate the region for this. By applying these methods, we were able to answer the question: “Where and for what functions are roadside rest areas needed?"