Hongtai Yang - Academia.edu (original) (raw)

Papers by Hongtai Yang

2019 5th International Conference on Transportation Information and Safety (ICTIS)

Traditional taxi has been criticized for underserving regions far away from downtown, leading to ... more Traditional taxi has been criticized for underserving regions far away from downtown, leading to social inequity. However, there has been no evidence so far to support this argument. With the advent of e-hailing taxi services such as Uber and Lyft, it becomes possible to test this argument. Because e-hailing taxi trips are assigned to the drivers who are willing to undertake the rides, the e-hailing taxi trips plus the traditional taxi trips can be regarded as the true travel demand served by taxi. The proportion of e-hailing taxi trips to total taxi trips is used as an indicator of to what extent area is underserved by traditional taxi. All the origins of traditional taxi and e-hailing taxi trips in New York City from January 2015 to December 2017 are aggregated at the level of taxi zones, which is defined by the New York City Taxi Limousine Commission. Fractional Response Model (FRM) is used to identify factors that influence the proportion of e-hailing trips. Results show that the proportion of African-American, the proportion of households of income less than 50,000 dollars, the proportion of household of income between 100,000 to 200,000 dollars, road density, distance to the Midtown Center have positive impact on the proportion of e-hailing taxi trips, while the population density, subway station density, bus station density, existence of airport have negative impact on the proportion of e-hailing taxi trips.

Transportmetrica A: Transport Science

With the advent of e-hailing applications, ride-sourcing service has become popular and replaced ... more With the advent of e-hailing applications, ride-sourcing service has become popular and replaced a substantial portion of taxi services. It is crucial to study the impact of different management st...

Transportation Research Part A: Policy and Practice, 2020

Abstract Traffic engineers are making efforts to mitigate congestion and to improve efficiency at... more Abstract Traffic engineers are making efforts to mitigate congestion and to improve efficiency at intersections. The symmetric intersection (SI) can increase the capacity of intersections and is economical, practical, efficient and convenient. The pedestrians’ crossing patterns tailored for SI has not yet been studied. This paper not only develops three pedestrian crossing patterns but also analyzes crossing patterns from the aspects of efficiency and safety. For efficiency, delay models are proposed by considering through and diagonal pedestrian movements. For safety, exposure conflicts and the number of potential traffic accidents are analyzed. Then delay and potential accidents are converted into money value respectively and the total cost is calculated. The case study results show that SI performs better in terms of increasing capacity and decreasing pedestrian delay compared with conventional intersection. Crossing pattern 1 is efficient but unsafe while the total delay and safety cost of pattern 3 is usually the highest. The sensitivity analysis indicates that cycle length has a negative impact on average pedestrian cost and if critical flow ratio increases, the average pedestrian cost of pattern 1 and pattern 3 will increase and decrease respectively. Furthermore, the best pedestrian pattern choice under different values of cost per accident and cost of pedestrian delay is also studied.

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

Demand Responsive Connector (DRC) is a type of flexible transit service that connects the residen... more Demand Responsive Connector (DRC) is a type of flexible transit service that connects the residents of an area to a transportation hub. Previous studies on DRC have optimized the service design parameters with the objective to minimize the passengers’ travel time. However, the cost and profit of the service were neglected, making it difficult for DRC operators to use the optimization method and the optimized design. In order to fill this gap, the study explores the way to optimize DRC service design with the objective to maximize the profit considering under elastic demand. Rectangular service area and the case of one vehicle are used in this study. Travelling of the DRC vehicle in the service area is regarded as a traveling salesman problem. In this way, the expected travel distance, travel time, and service cycle are derived. The relationship between service design parameters and passenger demand has also been constructed. It has been observed that the profit can be expressed as a nonlinear function of the demand density and service design parameters, including fare, length and width of the service area. Optimal service design and the expected profit are given at different levels of demand density. Simulation is performed to verify the results. Sensitivity analysis is performed with respect to the design parameters when any other is fixed due to practical constraints. DRC operators can use the proposed method to perform feasibility study and to determine the profit of DRC service in an area.

Transportation Research Part D: Transport and Environment, 2022

Sustainable Cities and Society, 2021

Romanian Journal of Transport Infrastructure, 2020

This study aims to find the potential of Bus Rapid Transit (BRT) to attract the vehicle owners fr... more This study aims to find the potential of Bus Rapid Transit (BRT) to attract the vehicle owners from their personal vehicles i.e., motorcars and motorcycles. Stated preference survey (questionnaires) and interviews were conducted at BRT (Metro Bus) Stations for the prediction of the individuals shifting from their private vehicles to BRT. Questions were designed critically as per the requirements of the research related to numerous aspects of BRT use i.e., vehicle ownership of the travelers, driving license holder, demographic characteristics, choice to use BRT if the fare increases, trip purpose and their prior mode of transportation for the same trip. A total of 374 responses, as per the population of the study area (Islamabad-Rawalpindi, Pakistan), were collected. The Multinomial Logistic Regression (MNL) model has been employed for four categories of vehicle ownerships i.e., “Car owners using BRT”, “Bike owners using BRT”, “Both Car and Bike owners using BRT” and the last one whi...

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

As the popularity and importance of metro system increase in urban transportation systems around ... more As the popularity and importance of metro system increase in urban transportation systems around the world, metro station service area and accessibility gain wide attention from various audiences. This study employs a modeling approach to explore the impact of land use, metro service coverage, and station accessibility on metro ridership in six cities of the United States. Our analysis shows that the optimal metro buffer radius is not the same in different cities. The service coverage boundaries of 600 meters and 1200 meters are suitable for estimating the passenger level of metro transit. We also find that the adjusted R2 of each city in each buffer zone has a trend of first rising and then declining. Moreover, the model results of ridership on weekdays and weekends have similar trend. In addition, we collect 22 attributes to analyze and summarize the influencing factors of metro ridership. We find that the number of automobiles owned by families, urban population, number of workers and income have significantly positive influence on metro ridership.

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

Bike-sharing systems are becoming more and more popular both in the United States and around the ... more Bike-sharing systems are becoming more and more popular both in the United States and around the world due to their easy accessibility and environmental friendliness. At the end of 2016, more than 430 bike-sharing programs and nearly 2.3 million bikes were available to the public around the world. In the United States, 123 million trips have been made using shared bikes since 2010. In 2017, the number of trips made using shared bikes has reached 35 million, which is 25\% higher than that of 2016. As an increasingly popular mode of transportation, bike-sharing systems are designed for short-distance trips, which not only improves the efficiency of short-distance travels but also alleviates traffic congestion and air pollution. In addition, interests in bike-sharing systems have been fueled by several cities, including Washington DC, where bike share has quickly become a convenient and popular transportation option. Feasibility is the first to study for parties considering implementing a bike-sharing system, detailed information such as the location of stations, number of shared bikes and especially the appropriate size of catchment area should be estimated precisely by system planners. Afterwards, with such information reasonable policies can be made to ensure the operational efficiency of system and maximize system-wide ridership. However, little information is available on what size of an appropriate catchment area should be used. Due to its simplicity in application, direct demand model is gaining more attention in demand forecasting. In this study, direct demand models were used to explore the best catchment area of the bike-sharing stations in Chicago, USA. In order to find out the best catchment area, multiple radii distance range from 200 m to 800 m were established around stations in the system. Results indicated that model fitting results do not vary among different catchment areas. Thus, for purpose of completing their studies, whatever catchment area is readily available or calculated can be used by direct demand modelers. And more attention should be paid by researchers to explore the appropriate boundaries in the future.

ABSTRACTBike sharing, as an important component of urban public transportation, has played a more... more ABSTRACTBike sharing, as an important component of urban public transportation, has played a more important role during the COVID-19 pandemic because users could ride bikes in open space and avoid the risk of infection. Leveraging the trip data of the Divvy bike sharing system in Chicago, this study sets to explore the change of ridership that COVID-19 has brought and the built environment factors that influence the spatial variation of ridership under the pandemic. Results show that the ridership declines by xx% in total. To account for the spatially heterogeneous relationship between the built environment and the ridership, the geographically weighted regression (GWR) model and the semi-parametric GWR (S-GWR) model are constructed. By comparing the model results, we find that the S-GWR model outperforms the GWR and the multiple linear regression model. The results of the S-GWR model indicates that education employment density, distance to subway, COVID-19 cases and ridership befor...

Journal of Advanced Transportation, 2021

Direct ridership models can predict station-level urban rail transit ridership. Previous research... more Direct ridership models can predict station-level urban rail transit ridership. Previous research indicates that the direct modeling of urban rail transit ridership uses different coverage overlapping area processing methods (such as naive method or Thiessen polygons), area analysis units (such as census block group and census tract), and various regression models (such as linear regression and negative binomial regression). However, the selection of these methods and models seems arbitrary. The objective of this research is to suggest methods of station-level urban rail transit ridership model selection and evaluate the impact of this selection on ridership model results and prediction accuracy. Urban rail transit ridership data in 2010 were collected from five cities: New York, San Francisco, Chicago, Philadelphia, and Boston. Using the built environment characteristics as the independent variables and station-level ridership as the dependent variable, an analysis was conducted to...

ISPRS International Journal of Geo-Information, 2021

Population aging has become a notable and enduring demographic phenomenon worldwide. Older adults... more Population aging has become a notable and enduring demographic phenomenon worldwide. Older adults’ walking behavior is determined by many factors, such as socioeconomic attributes and the built environment. Although a handful of recent studies have examined the influence of street greenery (a built environment variable readily estimated by big data) on older adults’ walking behavior, they have not focused on the spatial heterogeneity in the influence. To this end, this study extracts the socioeconomic and walking behavior data from the Travel Characteristic Survey 2011 of Hong Kong and estimates street greenery (the green view index) based on Google Street View imagery. It then develops global models (linear regression and Box–Cox transformed models) and local models (geographically weighted regression models) to scrutinize the average (global) and location-specific (local) relationships, respectively, between street greenery and older adults’ walking time. Notably, green view indic...

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

This paper takes the New York Citi Bike public bicycle system as the research object, and uses th... more This paper takes the New York Citi Bike public bicycle system as the research object, and uses the public bicycle historical operation data, weather data, and holiday information to propose a short-term demand forecasting method for the total lending amount of the stations in the next hour based on machine learning approaches. This study extends the existing literature in the following three aspects: (1) we clustered bike stations creatively by a new spatial constrained clustering method; (2) it used the nested sliding window method to reduce the over-fitting risk of the prediction model and verifies the accuracy of the model prediction results; (3) we exacted new time series features and applied them to the linear prediction model, the prediction results are compared with the nonlinear models, and it is found that the linear model outperformed the non-linear model in predicting station demand.

Journal of Transport Geography, 2020

Bus rapid transit (BRT) systems have mushroomed worldwide in the last few decades. An enriched un... more Bus rapid transit (BRT) systems have mushroomed worldwide in the last few decades. An enriched understanding of BRT capitalization effects is essential. Although the BRT accessibility effect on housing prices has been extensively explored, the effect of proximity to the BRT corridor (which may be related to unattractive landscape and noise pollution) has been little scrutinized. More importantly, whether and how the two effects vary across price levels and space have yet to be sufficiently studied. To this end, we estimate the effect of BRT accessibility and proximity on housing prices by applying a battery of econometric methods (including hedonic pricing models, spatial regression models, quantile regression models, and a geographically weighted regression model) to 5185 observations in the housing market in Xiamen Island, China. The results of this study are: (1) BRT accessibility premiums and proximity penalties simultaneously exist in the housing market; (2) buyers of high-priced housing have a greater willingness to pay for avoiding the nuisances attributed to proximity to the BRT corridor; (3) the effect of BRT on housing prices is spatially heterogeneous; (4) the BRT accessibility effect is larger in suburban areas than in urban areas; and (5) housing prices are more predictable near the city centers than outside the area, which may be because a greater proportion of the price of a house near the city centers is derived from the location (rather than the building structure). Finally, policy implications (e.g., building acoustic barriers and planting vegetation along the BRT corridor and improving the transit service in suburban areas) are discussed.

Sustainability, 2020

Walking and cycling are not only frequently-used modes of transport but also popular physical act... more Walking and cycling are not only frequently-used modes of transport but also popular physical activities. They are beneficial to traffic congestion mitigation, air pollution reduction, and public health promotion. Hence, examining and comparing the built environment correlates of the propensity of walking and cycling is of great interest to urban practitioners and decision-makers and has attracted extensive research attention. However, existing studies mainly look into the two modes separately or consider them as an integral (i.e., active travel), and few compare built environment correlates of their propensity in a single study, especially in the developing world context. Thus, this study, taking Xiamen, China, as a case, examines the built environment correlates of the propensity of walking and cycling simultaneously and compares the results wherever feasible. It found (1) built environment correlates of the propensity of walking and cycling differ with each other largely in direc...

International Journal of Injury Control and Safety Promotion, 2020

Abstract Although many studies have investigated the correlations between injury severities and s... more Abstract Although many studies have investigated the correlations between injury severities and seat positions, few researchers explored the correlates of injury severities (e.g., seat positions) within a crash that results in multiple occupant injuries. Therefore, we examine the injury correlates within and between crashes, and study the correlations between seat positions and occupant injury severity by constructing a hierarchical ordered probit model. A total of 20,327 occupant injuries in 16,405 motor vehicle crashes in South Australia (2012 − 2016) are used. The results of this study indicate that the rear left passenger seat is associated with a 7.66% higher chance of getting injured (including moderate and severe injury), and the front left passenger seat is associated with a 2.94% higher chance of getting injured compared with the driver seat. Besides, the higher injury chances for other passenger seats including the rear right and rear middle seats are 4.97% and 4.74%, respectively, compared with the driver seat. Thus, this study offers passengers insightful suggestions about how to protect themselves by choosing the right passenger seat in a vehicle.

Journal of Advanced Transportation, 2020

In this paper, a bus priority signal control (BPSC) method based on delays of passengers and pede... more In this paper, a bus priority signal control (BPSC) method based on delays of passengers and pedestrians at adjacent intersections, is proposed. The influences of BPSC on passenger and pedestrian delay at adjacent intersections under the condition of coordinated control of green waves are studied. The implementation of BPSC at intersections not only reduces the delay of bus passengers, social vehicle passengers and pedestrians, but also improves the traffic flow of priority buses and social vehicles at downstream intersections. This study takes the green phase extension as an example of the active BPSC strategy, and analyzes three cases of priority vehicles reaching downstream intersection. Firstly, passenger and pedestrian delays at adjacent intersections are calculated under different traffic situations. Secondly, models with the goal of maximizing the reduced total delays are established. Thirdly, three algorithms are used to solve the problem to obtain the optimal signal timing ...

Transportation Research Part D: Transport and Environment, 2019

Mini electric cars (mini-EVs) are gaining popularity in many areas in China (∼4-5 million ownersh... more Mini electric cars (mini-EVs) are gaining popularity in many areas in China (∼4-5 million ownership). Mini-EVs are a class of enclosed vehicle smaller than conventional cars. The average range of a mini-EVs is about 100 km, with a maximum speed ranging from 40 to 60 km/h. Their adoption has generated regulatory uncertainty and their classification is ambiguous. While there have been many studies focused on New Energy Vehicles (NEV) (e.g., battery electric conventional car) acceptance rates, purchase intention, and driving behavior; little research has focused on mini-EVs. This paper relies on structured interviews to shed initial light the motives for mini-EV choice and purchase, model choice, travel behavior, and safety. The intention of this paper is to explore key market issues for further analysis and policy intervention; specifically, we aim to profile users and use patterns to inform policy on vehicle standards, licensing, on-road regulations, and subsidy policy. This is the first paper to do this. In-depth interviews with 34 mini-EV owners in Kunming, China reveal an owner profile that is predominately retired male with high household income. Less than half of users have a driver license. Their purchase motives are mostly driven by their age or physical limitations, the convenience and low cost of the vehicle and charging, and the vehicles' low speed. Most users transitioned from using e-bikes and public transit. Policy implications include standardizing mini-EVs designs, imposing a license system for mini-EVs and their users, and sustaining low-speed vehicle infrastructure.

2019 5th International Conference on Transportation Information and Safety (ICTIS)

Traditional taxi has been criticized for underserving regions far away from downtown, leading to ... more Traditional taxi has been criticized for underserving regions far away from downtown, leading to social inequity. However, there has been no evidence so far to support this argument. With the advent of e-hailing taxi services such as Uber and Lyft, it becomes possible to test this argument. Because e-hailing taxi trips are assigned to the drivers who are willing to undertake the rides, the e-hailing taxi trips plus the traditional taxi trips can be regarded as the true travel demand served by taxi. The proportion of e-hailing taxi trips to total taxi trips is used as an indicator of to what extent area is underserved by traditional taxi. All the origins of traditional taxi and e-hailing taxi trips in New York City from January 2015 to December 2017 are aggregated at the level of taxi zones, which is defined by the New York City Taxi Limousine Commission. Fractional Response Model (FRM) is used to identify factors that influence the proportion of e-hailing trips. Results show that the proportion of African-American, the proportion of households of income less than 50,000 dollars, the proportion of household of income between 100,000 to 200,000 dollars, road density, distance to the Midtown Center have positive impact on the proportion of e-hailing taxi trips, while the population density, subway station density, bus station density, existence of airport have negative impact on the proportion of e-hailing taxi trips.

Transportmetrica A: Transport Science

With the advent of e-hailing applications, ride-sourcing service has become popular and replaced ... more With the advent of e-hailing applications, ride-sourcing service has become popular and replaced a substantial portion of taxi services. It is crucial to study the impact of different management st...

Transportation Research Part A: Policy and Practice, 2020

Abstract Traffic engineers are making efforts to mitigate congestion and to improve efficiency at... more Abstract Traffic engineers are making efforts to mitigate congestion and to improve efficiency at intersections. The symmetric intersection (SI) can increase the capacity of intersections and is economical, practical, efficient and convenient. The pedestrians’ crossing patterns tailored for SI has not yet been studied. This paper not only develops three pedestrian crossing patterns but also analyzes crossing patterns from the aspects of efficiency and safety. For efficiency, delay models are proposed by considering through and diagonal pedestrian movements. For safety, exposure conflicts and the number of potential traffic accidents are analyzed. Then delay and potential accidents are converted into money value respectively and the total cost is calculated. The case study results show that SI performs better in terms of increasing capacity and decreasing pedestrian delay compared with conventional intersection. Crossing pattern 1 is efficient but unsafe while the total delay and safety cost of pattern 3 is usually the highest. The sensitivity analysis indicates that cycle length has a negative impact on average pedestrian cost and if critical flow ratio increases, the average pedestrian cost of pattern 1 and pattern 3 will increase and decrease respectively. Furthermore, the best pedestrian pattern choice under different values of cost per accident and cost of pedestrian delay is also studied.

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

Demand Responsive Connector (DRC) is a type of flexible transit service that connects the residen... more Demand Responsive Connector (DRC) is a type of flexible transit service that connects the residents of an area to a transportation hub. Previous studies on DRC have optimized the service design parameters with the objective to minimize the passengers’ travel time. However, the cost and profit of the service were neglected, making it difficult for DRC operators to use the optimization method and the optimized design. In order to fill this gap, the study explores the way to optimize DRC service design with the objective to maximize the profit considering under elastic demand. Rectangular service area and the case of one vehicle are used in this study. Travelling of the DRC vehicle in the service area is regarded as a traveling salesman problem. In this way, the expected travel distance, travel time, and service cycle are derived. The relationship between service design parameters and passenger demand has also been constructed. It has been observed that the profit can be expressed as a nonlinear function of the demand density and service design parameters, including fare, length and width of the service area. Optimal service design and the expected profit are given at different levels of demand density. Simulation is performed to verify the results. Sensitivity analysis is performed with respect to the design parameters when any other is fixed due to practical constraints. DRC operators can use the proposed method to perform feasibility study and to determine the profit of DRC service in an area.

Transportation Research Part D: Transport and Environment, 2022

Sustainable Cities and Society, 2021

Romanian Journal of Transport Infrastructure, 2020

This study aims to find the potential of Bus Rapid Transit (BRT) to attract the vehicle owners fr... more This study aims to find the potential of Bus Rapid Transit (BRT) to attract the vehicle owners from their personal vehicles i.e., motorcars and motorcycles. Stated preference survey (questionnaires) and interviews were conducted at BRT (Metro Bus) Stations for the prediction of the individuals shifting from their private vehicles to BRT. Questions were designed critically as per the requirements of the research related to numerous aspects of BRT use i.e., vehicle ownership of the travelers, driving license holder, demographic characteristics, choice to use BRT if the fare increases, trip purpose and their prior mode of transportation for the same trip. A total of 374 responses, as per the population of the study area (Islamabad-Rawalpindi, Pakistan), were collected. The Multinomial Logistic Regression (MNL) model has been employed for four categories of vehicle ownerships i.e., “Car owners using BRT”, “Bike owners using BRT”, “Both Car and Bike owners using BRT” and the last one whi...

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

As the popularity and importance of metro system increase in urban transportation systems around ... more As the popularity and importance of metro system increase in urban transportation systems around the world, metro station service area and accessibility gain wide attention from various audiences. This study employs a modeling approach to explore the impact of land use, metro service coverage, and station accessibility on metro ridership in six cities of the United States. Our analysis shows that the optimal metro buffer radius is not the same in different cities. The service coverage boundaries of 600 meters and 1200 meters are suitable for estimating the passenger level of metro transit. We also find that the adjusted R2 of each city in each buffer zone has a trend of first rising and then declining. Moreover, the model results of ridership on weekdays and weekends have similar trend. In addition, we collect 22 attributes to analyze and summarize the influencing factors of metro ridership. We find that the number of automobiles owned by families, urban population, number of workers and income have significantly positive influence on metro ridership.

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

Bike-sharing systems are becoming more and more popular both in the United States and around the ... more Bike-sharing systems are becoming more and more popular both in the United States and around the world due to their easy accessibility and environmental friendliness. At the end of 2016, more than 430 bike-sharing programs and nearly 2.3 million bikes were available to the public around the world. In the United States, 123 million trips have been made using shared bikes since 2010. In 2017, the number of trips made using shared bikes has reached 35 million, which is 25\% higher than that of 2016. As an increasingly popular mode of transportation, bike-sharing systems are designed for short-distance trips, which not only improves the efficiency of short-distance travels but also alleviates traffic congestion and air pollution. In addition, interests in bike-sharing systems have been fueled by several cities, including Washington DC, where bike share has quickly become a convenient and popular transportation option. Feasibility is the first to study for parties considering implementing a bike-sharing system, detailed information such as the location of stations, number of shared bikes and especially the appropriate size of catchment area should be estimated precisely by system planners. Afterwards, with such information reasonable policies can be made to ensure the operational efficiency of system and maximize system-wide ridership. However, little information is available on what size of an appropriate catchment area should be used. Due to its simplicity in application, direct demand model is gaining more attention in demand forecasting. In this study, direct demand models were used to explore the best catchment area of the bike-sharing stations in Chicago, USA. In order to find out the best catchment area, multiple radii distance range from 200 m to 800 m were established around stations in the system. Results indicated that model fitting results do not vary among different catchment areas. Thus, for purpose of completing their studies, whatever catchment area is readily available or calculated can be used by direct demand modelers. And more attention should be paid by researchers to explore the appropriate boundaries in the future.

ABSTRACTBike sharing, as an important component of urban public transportation, has played a more... more ABSTRACTBike sharing, as an important component of urban public transportation, has played a more important role during the COVID-19 pandemic because users could ride bikes in open space and avoid the risk of infection. Leveraging the trip data of the Divvy bike sharing system in Chicago, this study sets to explore the change of ridership that COVID-19 has brought and the built environment factors that influence the spatial variation of ridership under the pandemic. Results show that the ridership declines by xx% in total. To account for the spatially heterogeneous relationship between the built environment and the ridership, the geographically weighted regression (GWR) model and the semi-parametric GWR (S-GWR) model are constructed. By comparing the model results, we find that the S-GWR model outperforms the GWR and the multiple linear regression model. The results of the S-GWR model indicates that education employment density, distance to subway, COVID-19 cases and ridership befor...

Journal of Advanced Transportation, 2021

Direct ridership models can predict station-level urban rail transit ridership. Previous research... more Direct ridership models can predict station-level urban rail transit ridership. Previous research indicates that the direct modeling of urban rail transit ridership uses different coverage overlapping area processing methods (such as naive method or Thiessen polygons), area analysis units (such as census block group and census tract), and various regression models (such as linear regression and negative binomial regression). However, the selection of these methods and models seems arbitrary. The objective of this research is to suggest methods of station-level urban rail transit ridership model selection and evaluate the impact of this selection on ridership model results and prediction accuracy. Urban rail transit ridership data in 2010 were collected from five cities: New York, San Francisco, Chicago, Philadelphia, and Boston. Using the built environment characteristics as the independent variables and station-level ridership as the dependent variable, an analysis was conducted to...

ISPRS International Journal of Geo-Information, 2021

Population aging has become a notable and enduring demographic phenomenon worldwide. Older adults... more Population aging has become a notable and enduring demographic phenomenon worldwide. Older adults’ walking behavior is determined by many factors, such as socioeconomic attributes and the built environment. Although a handful of recent studies have examined the influence of street greenery (a built environment variable readily estimated by big data) on older adults’ walking behavior, they have not focused on the spatial heterogeneity in the influence. To this end, this study extracts the socioeconomic and walking behavior data from the Travel Characteristic Survey 2011 of Hong Kong and estimates street greenery (the green view index) based on Google Street View imagery. It then develops global models (linear regression and Box–Cox transformed models) and local models (geographically weighted regression models) to scrutinize the average (global) and location-specific (local) relationships, respectively, between street greenery and older adults’ walking time. Notably, green view indic...

2019 5th International Conference on Transportation Information and Safety (ICTIS), 2019

This paper takes the New York Citi Bike public bicycle system as the research object, and uses th... more This paper takes the New York Citi Bike public bicycle system as the research object, and uses the public bicycle historical operation data, weather data, and holiday information to propose a short-term demand forecasting method for the total lending amount of the stations in the next hour based on machine learning approaches. This study extends the existing literature in the following three aspects: (1) we clustered bike stations creatively by a new spatial constrained clustering method; (2) it used the nested sliding window method to reduce the over-fitting risk of the prediction model and verifies the accuracy of the model prediction results; (3) we exacted new time series features and applied them to the linear prediction model, the prediction results are compared with the nonlinear models, and it is found that the linear model outperformed the non-linear model in predicting station demand.

Journal of Transport Geography, 2020

Bus rapid transit (BRT) systems have mushroomed worldwide in the last few decades. An enriched un... more Bus rapid transit (BRT) systems have mushroomed worldwide in the last few decades. An enriched understanding of BRT capitalization effects is essential. Although the BRT accessibility effect on housing prices has been extensively explored, the effect of proximity to the BRT corridor (which may be related to unattractive landscape and noise pollution) has been little scrutinized. More importantly, whether and how the two effects vary across price levels and space have yet to be sufficiently studied. To this end, we estimate the effect of BRT accessibility and proximity on housing prices by applying a battery of econometric methods (including hedonic pricing models, spatial regression models, quantile regression models, and a geographically weighted regression model) to 5185 observations in the housing market in Xiamen Island, China. The results of this study are: (1) BRT accessibility premiums and proximity penalties simultaneously exist in the housing market; (2) buyers of high-priced housing have a greater willingness to pay for avoiding the nuisances attributed to proximity to the BRT corridor; (3) the effect of BRT on housing prices is spatially heterogeneous; (4) the BRT accessibility effect is larger in suburban areas than in urban areas; and (5) housing prices are more predictable near the city centers than outside the area, which may be because a greater proportion of the price of a house near the city centers is derived from the location (rather than the building structure). Finally, policy implications (e.g., building acoustic barriers and planting vegetation along the BRT corridor and improving the transit service in suburban areas) are discussed.

Sustainability, 2020

Walking and cycling are not only frequently-used modes of transport but also popular physical act... more Walking and cycling are not only frequently-used modes of transport but also popular physical activities. They are beneficial to traffic congestion mitigation, air pollution reduction, and public health promotion. Hence, examining and comparing the built environment correlates of the propensity of walking and cycling is of great interest to urban practitioners and decision-makers and has attracted extensive research attention. However, existing studies mainly look into the two modes separately or consider them as an integral (i.e., active travel), and few compare built environment correlates of their propensity in a single study, especially in the developing world context. Thus, this study, taking Xiamen, China, as a case, examines the built environment correlates of the propensity of walking and cycling simultaneously and compares the results wherever feasible. It found (1) built environment correlates of the propensity of walking and cycling differ with each other largely in direc...

International Journal of Injury Control and Safety Promotion, 2020

Abstract Although many studies have investigated the correlations between injury severities and s... more Abstract Although many studies have investigated the correlations between injury severities and seat positions, few researchers explored the correlates of injury severities (e.g., seat positions) within a crash that results in multiple occupant injuries. Therefore, we examine the injury correlates within and between crashes, and study the correlations between seat positions and occupant injury severity by constructing a hierarchical ordered probit model. A total of 20,327 occupant injuries in 16,405 motor vehicle crashes in South Australia (2012 − 2016) are used. The results of this study indicate that the rear left passenger seat is associated with a 7.66% higher chance of getting injured (including moderate and severe injury), and the front left passenger seat is associated with a 2.94% higher chance of getting injured compared with the driver seat. Besides, the higher injury chances for other passenger seats including the rear right and rear middle seats are 4.97% and 4.74%, respectively, compared with the driver seat. Thus, this study offers passengers insightful suggestions about how to protect themselves by choosing the right passenger seat in a vehicle.

Journal of Advanced Transportation, 2020

In this paper, a bus priority signal control (BPSC) method based on delays of passengers and pede... more In this paper, a bus priority signal control (BPSC) method based on delays of passengers and pedestrians at adjacent intersections, is proposed. The influences of BPSC on passenger and pedestrian delay at adjacent intersections under the condition of coordinated control of green waves are studied. The implementation of BPSC at intersections not only reduces the delay of bus passengers, social vehicle passengers and pedestrians, but also improves the traffic flow of priority buses and social vehicles at downstream intersections. This study takes the green phase extension as an example of the active BPSC strategy, and analyzes three cases of priority vehicles reaching downstream intersection. Firstly, passenger and pedestrian delays at adjacent intersections are calculated under different traffic situations. Secondly, models with the goal of maximizing the reduced total delays are established. Thirdly, three algorithms are used to solve the problem to obtain the optimal signal timing ...

Transportation Research Part D: Transport and Environment, 2019

Mini electric cars (mini-EVs) are gaining popularity in many areas in China (∼4-5 million ownersh... more Mini electric cars (mini-EVs) are gaining popularity in many areas in China (∼4-5 million ownership). Mini-EVs are a class of enclosed vehicle smaller than conventional cars. The average range of a mini-EVs is about 100 km, with a maximum speed ranging from 40 to 60 km/h. Their adoption has generated regulatory uncertainty and their classification is ambiguous. While there have been many studies focused on New Energy Vehicles (NEV) (e.g., battery electric conventional car) acceptance rates, purchase intention, and driving behavior; little research has focused on mini-EVs. This paper relies on structured interviews to shed initial light the motives for mini-EV choice and purchase, model choice, travel behavior, and safety. The intention of this paper is to explore key market issues for further analysis and policy intervention; specifically, we aim to profile users and use patterns to inform policy on vehicle standards, licensing, on-road regulations, and subsidy policy. This is the first paper to do this. In-depth interviews with 34 mini-EV owners in Kunming, China reveal an owner profile that is predominately retired male with high household income. Less than half of users have a driver license. Their purchase motives are mostly driven by their age or physical limitations, the convenience and low cost of the vehicle and charging, and the vehicles' low speed. Most users transitioned from using e-bikes and public transit. Policy implications include standardizing mini-EVs designs, imposing a license system for mini-EVs and their users, and sustaining low-speed vehicle infrastructure.