This page has only limited features, please log in for full access.

Prof. Dr. Lee Der-Horng
Department of Civil and Environmental Engineering, National University of Singapore, Singapore 117576, Singapore

Basic Info

Basic Info is private.

Research Keywords & Expertise

0 Transportation Policy
0 public transportation
0 Urban and regional travel demand forecasting
0 Intelligent transport systems (ITSs)
0 Taxi and private-hire competition and strategy

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Journal article
Published: 26 February 2021 in Journal of Infrastructure, Policy and Development
Reads 0
Downloads 0

Ride-hailing or private hire has taken the Singapore transport network by storm in the past few years. Singapore has had more than three revisions of its ride-hailing regulation in the six years since the arrival of the disruptive technology. Often quoted in the list of cities with commendable public transport policy, Singapore still manages to find a viable and significant position for ride-hailing. Cities from around the world are all searching for a model of regulation for ride-hailing that can be elevated as a benchmark. Singapore, to a large extent, has formulated a successful model based on current market parameters and, more importantly, an adaptive one that evolves constantly with the constantly disruptive technology. The experts and regulators of the Singapore transport sector were interviewed in depth, tapping into their opinions and technocratic commentaries on the city-state’s Point-to-Point, or P2P, sector regulation. The data were analyzed using the three-element model of social practice theory as an alternative to conventional behavioral studies, thereby eliminating bias on the commuters and rather shifting focus to the practice. Content analysis utilizing QDA is executed for categorization through fine-level inductive matrix coding to elaborate upon the policy derivatives of the Singapore model. The unique addition of the research to ride-hailing policy is the comprehension of the commonalities and patterns across industrial and technological disruption, practice and policy irrespective of sectoral variations, thanks to the utilization of social practice theory. The first-of-its-kind policy exercise in the sector can be repeated for any city, which is a direct testament to the simplicity and exhaustivity of the methodology, benefiting both operators and investors through equitable policy formulation.

ACS Style

Sreyus Palliyani; Der-Horng Lee. Analyzing Singapore’s ride-hailing regulation through its technocracy using social practice theory. Journal of Infrastructure, Policy and Development 2021, 5, 1254 .

AMA Style

Sreyus Palliyani, Der-Horng Lee. Analyzing Singapore’s ride-hailing regulation through its technocracy using social practice theory. Journal of Infrastructure, Policy and Development. 2021; 5 (1):1254.

Chicago/Turabian Style

Sreyus Palliyani; Der-Horng Lee. 2021. "Analyzing Singapore’s ride-hailing regulation through its technocracy using social practice theory." Journal of Infrastructure, Policy and Development 5, no. 1: 1254.

Journal article
Published: 29 August 2020 in Transportation Research Part E: Logistics and Transportation Review
Reads 0
Downloads 0

This paper investigates the transshipment operations between vessels and trains in seaport rail terminals. In order to get a more effective transshipment plan, the schedule plan of trains and the transshipment plan of containers among vessels, yards, and trains are determined simultaneously. To this end, a mixed integer programming (MIP) model is proposed to integrate the two sub-problems with the objective of minimizing the total operation cost, in which the service time window and unloading time requirement of trains are considered. It is demonstrated that some variables in the model can be relaxed without influencing the optimal result. Moreover, a set of valid inequalities are introduced to tighten the constraints. The result experiments show that the enhanced model can be solved more effectively. Then, extensive experiments have been conducted to analyze the influence of several factors, including the handling capacity, the yard capacity, and the value of unit cost. The results report that the handling capacity shows a significant effect on the performance of the transfer plan, and increasing the storage cost of import containers leads to a more effective transshipment plan.

ACS Style

Baicheng Yan; Jian Gang Jin; Xiaoning Zhu; Der-Horng Lee; Li Wang; Hua Wang. Integrated planning of train schedule template and container transshipment operation in seaport railway terminals. Transportation Research Part E: Logistics and Transportation Review 2020, 142, 102061 .

AMA Style

Baicheng Yan, Jian Gang Jin, Xiaoning Zhu, Der-Horng Lee, Li Wang, Hua Wang. Integrated planning of train schedule template and container transshipment operation in seaport railway terminals. Transportation Research Part E: Logistics and Transportation Review. 2020; 142 ():102061.

Chicago/Turabian Style

Baicheng Yan; Jian Gang Jin; Xiaoning Zhu; Der-Horng Lee; Li Wang; Hua Wang. 2020. "Integrated planning of train schedule template and container transshipment operation in seaport railway terminals." Transportation Research Part E: Logistics and Transportation Review 142, no. : 102061.

Journal article
Published: 25 February 2020 in Transportation Research Part C: Emerging Technologies
Reads 0
Downloads 0

Rapid urbanization and modern civilization require sound integration with public transportation systems. In the same time, the volume and complexity of public transportation network are increasing, making it harder to understand the public transportation dynamics. As a first step, understanding the similarity among subway stations is imperative. In this paper, we proposed a semantic framework inspired from natural language processing (NLP) to interpret subway stations as compound words. Specifically, we transplanted context and literal meaning of compound words into mobility and location attributes of stations. Using smart card data, we trained stacked autoencoders (SAE) with designed flow matrices as an embedding method to learn the mobility attributes. Subsequently, to discover the location attributes, we have applied affinity propagation clustering to classify 9 point of interest (POI) categories. Combined with urban planning knowledge, we manage to comprehend the land use meanings of 9 POI clusters. The location semantics is chosen from those categories reflecting its urban land use pattern. By choose meaningful combination of mobility and location semantics for stations’ similarity case studies, we summarized potential applications of this semantic framework.

ACS Style

Dingyi Zhuang; Siyu Hao; Der-Horng Lee; Jian Gang Jin. From compound word to metropolitan station: Semantic similarity analysis using smart card data. Transportation Research Part C: Emerging Technologies 2020, 114, 322 -337.

AMA Style

Dingyi Zhuang, Siyu Hao, Der-Horng Lee, Jian Gang Jin. From compound word to metropolitan station: Semantic similarity analysis using smart card data. Transportation Research Part C: Emerging Technologies. 2020; 114 ():322-337.

Chicago/Turabian Style

Dingyi Zhuang; Siyu Hao; Der-Horng Lee; Jian Gang Jin. 2020. "From compound word to metropolitan station: Semantic similarity analysis using smart card data." Transportation Research Part C: Emerging Technologies 114, no. : 322-337.

Journal article
Published: 17 January 2020 in Computers & Industrial Engineering
Reads 0
Downloads 0

This paper tackles the sea-rail transshipment operation problem of seaport rail terminals, which includes two key sub-problems involved in sea-rail intermodal container transportation, namely train schedule template and transshipment plan of inbound containers. With limited resources and time constraints, operators need to decide the placed-in and taken-out time of trains to coordinate with vessels’ unloading time and the transshipment plan of inbound containers (i.e. the amount of containers that are transshipped between different vessels and trains in each time slot) to maximize the number of direct-transshipment containers while minimizing the storage time and dwell time of inbound containers. The problem is formulated as an integer programming model, and a tailored rolling horizon approach with the adaptive horizon and backtracking strategy is proposed. The performance of the algorithm is verified by a set of instances. The results suggest that the handling capacity of rail-mounted gantry cranes shows a more significant effect on the performance of transshipment operation than other factors. The negative effect caused by insufficient handling capacity could be alleviated by methods like prolonging the feasible service time of trains and enhancing the operational capacity of shunting engines.

ACS Style

Baicheng Yan; Xiaoning Zhu; Der-Horng Lee; Jian Gang Jin; Li Wang. Transshipment operations optimization of sea-rail intermodal container in seaport rail terminals. Computers & Industrial Engineering 2020, 141, 106296 .

AMA Style

Baicheng Yan, Xiaoning Zhu, Der-Horng Lee, Jian Gang Jin, Li Wang. Transshipment operations optimization of sea-rail intermodal container in seaport rail terminals. Computers & Industrial Engineering. 2020; 141 ():106296.

Chicago/Turabian Style

Baicheng Yan; Xiaoning Zhu; Der-Horng Lee; Jian Gang Jin; Li Wang. 2020. "Transshipment operations optimization of sea-rail intermodal container in seaport rail terminals." Computers & Industrial Engineering 141, no. : 106296.

Journal article
Published: 14 November 2019 in Transportation Research Part A: Policy and Practice
Reads 0
Downloads 0

As a green transport means, electric vehicle (EV) has received widespread attention in recent years and an increasing number of cities have been establishing their EV transport systems including EV fleet management and charging infrastructure. Transport policy-makers are concerning about the system performance of an EV charging system measured by energy consumption and user experience. We in this paper aim to develop an effective method for the expected total energy consumption estimation (ETEC) of EV charging systems deployed in a dense city. To achieve this objective, we firstly introduce the nonlinear charging profile, its impacts on energy consumption as well as user experience, and present an approach for estimating the nonlinear charging time. We then elaborate our method to estimate energy consumption for one-time EV charging by addressing four kinds of energy losses in charging process. Next, charging frequency by considering multi-type EVs, and their heterogeneities and different charging needs for normal and fast charging systems is analyzed in depth. These two together determine the network-wide energy consumption and a pro-rated approach is used to figure out the spatial distribution of energy consumption. A case study of Singapore is conducted in the end to validate the proposed methodology. Numerical results reveal a trade-off between energy saving and user experience, and also demonstrate the importance of considering heterogeneities of driving range, charging preference and daily travel mileage.

ACS Style

Hua Wang; De Zhao; Qiang Meng; Ghim Ping Ong; Der-Horng Lee. Network-level energy consumption estimation for electric vehicles considering vehicle and user heterogeneity. Transportation Research Part A: Policy and Practice 2019, 132, 30 -46.

AMA Style

Hua Wang, De Zhao, Qiang Meng, Ghim Ping Ong, Der-Horng Lee. Network-level energy consumption estimation for electric vehicles considering vehicle and user heterogeneity. Transportation Research Part A: Policy and Practice. 2019; 132 ():30-46.

Chicago/Turabian Style

Hua Wang; De Zhao; Qiang Meng; Ghim Ping Ong; Der-Horng Lee. 2019. "Network-level energy consumption estimation for electric vehicles considering vehicle and user heterogeneity." Transportation Research Part A: Policy and Practice 132, no. : 30-46.

Journal article
Published: 02 December 2018 in Transportation Research Part A: Policy and Practice
Reads 0
Downloads 0

In the recent decade, electric vehicles (EVs), as a clean and cost-effective transport means, are paving the way to replace conventional gasoline vehicles. To facilitate wider adoption of EVs, corresponding charging infrastructures have to be established first. In this paper, we propose a four-step method to deploy normal and fast charging stations that can satisfy the charging demand of private EVs, 1-shift and 2-shift EV taxis in a mature city. The proposed four-step method provides an easy-to-implement procedure for charging demand estimation and distribution. First, we derive the charging frequency and type of charging facilities for each type of EVs based on their technical specifications and operational characteristics. Then, total demand for normal and fast charging facilities can be generated by using up-to-date transport statistics, and these demand is allocated to various charging sites (car parks or petrol stations) based on spatial distribution of EVs. Given the average daily engaged working hours of a charger, service capacity at each charging station is thus determined. A case study of Singapore is put forward in the end and a scenario analysis is conducted to demonstrate the impact of driving range.

ACS Style

Hua Wang; De Zhao; Qiang Meng; Ghim Ping Ong; Der-Horng Lee. A four-step method for electric-vehicle charging facility deployment in a dense city: An empirical study in Singapore. Transportation Research Part A: Policy and Practice 2018, 119, 224 -237.

AMA Style

Hua Wang, De Zhao, Qiang Meng, Ghim Ping Ong, Der-Horng Lee. A four-step method for electric-vehicle charging facility deployment in a dense city: An empirical study in Singapore. Transportation Research Part A: Policy and Practice. 2018; 119 ():224-237.

Chicago/Turabian Style

Hua Wang; De Zhao; Qiang Meng; Ghim Ping Ong; Der-Horng Lee. 2018. "A four-step method for electric-vehicle charging facility deployment in a dense city: An empirical study in Singapore." Transportation Research Part A: Policy and Practice 119, no. : 224-237.

Research article
Published: 01 January 2017 in Transportation Research Record: Journal of the Transportation Research Board
Reads 0
Downloads 0

This study investigated the personal rapid transit (PRT) guideway network design problem at a strategic level. PRT is known as an on-demand mobility method serving the first or last mile of travel demand, which can fluctuate significantly during a day. This on-demand property may make the system vulnerable to changes in the pattern of demand. The robustness of the PRT guideway network refers to the capability to fit different demand patterns. The motivation of this study was to take the uncertainty of demand into consideration in the process of network design to enhance the robustness of the PRT guideway network in operation. This problem was formulated as a two-stage stochastic linear programming model. The model was applied to a case study with real travel demand data from Singapore. The results of the comparison study show that the network designed via the proposed model is robust and cost-effective.

ACS Style

Kangjia Zhao; Jian Gang Jin; Der-Horng Lee. Two-Stage Stochastic Programming Model for Robust Personal Rapid Transit Network Design. Transportation Research Record: Journal of the Transportation Research Board 2017, 2650, 152 -162.

AMA Style

Kangjia Zhao, Jian Gang Jin, Der-Horng Lee. Two-Stage Stochastic Programming Model for Robust Personal Rapid Transit Network Design. Transportation Research Record: Journal of the Transportation Research Board. 2017; 2650 (1):152-162.

Chicago/Turabian Style

Kangjia Zhao; Jian Gang Jin; Der-Horng Lee. 2017. "Two-Stage Stochastic Programming Model for Robust Personal Rapid Transit Network Design." Transportation Research Record: Journal of the Transportation Research Board 2650, no. 1: 152-162.

Conference paper
Published: 25 October 2016 in MATEC Web of Conferences
Reads 0
Downloads 0
ACS Style

Katarzyna A. Marczuk; Harold S.H. Soh; Carlos Lima Azevedo; Der-Horng Lee; Emilio Frazzoli. Simulation Framework for Rebalancing of Autonomous Mobility on Demand Systems. MATEC Web of Conferences 2016, 81, 01005 .

AMA Style

Katarzyna A. Marczuk, Harold S.H. Soh, Carlos Lima Azevedo, Der-Horng Lee, Emilio Frazzoli. Simulation Framework for Rebalancing of Autonomous Mobility on Demand Systems. MATEC Web of Conferences. 2016; 81 ():01005.

Chicago/Turabian Style

Katarzyna A. Marczuk; Harold S.H. Soh; Carlos Lima Azevedo; Der-Horng Lee; Emilio Frazzoli. 2016. "Simulation Framework for Rebalancing of Autonomous Mobility on Demand Systems." MATEC Web of Conferences 81, no. : 01005.

Journal article
Published: 01 June 2016 in Transportation Science
Reads 0
Downloads 0
ACS Style

Jian Gang Jin; Der-Horng Lee; Jin Xin Cao. Storage Yard Management in Maritime Container Terminals. Transportation Science 2016, 50, 1300 -1313.

AMA Style

Jian Gang Jin, Der-Horng Lee, Jin Xin Cao. Storage Yard Management in Maritime Container Terminals. Transportation Science. 2016; 50 (4):1300-1313.

Chicago/Turabian Style

Jian Gang Jin; Der-Horng Lee; Jin Xin Cao. 2016. "Storage Yard Management in Maritime Container Terminals." Transportation Science 50, no. 4: 1300-1313.

Journal article
Published: 01 April 2016 in Transportation Research Part E: Logistics and Transportation Review
Reads 0
Downloads 0

This paper investigates the network design problem arising from the regional hazardous waste management system. The problem is to identify the locations of various waste facilities, and determine the transportation routes of hazardous wastes and waste residues between those waste facilities. Aiming at minimizing jointly the total cost and total risk, the problem is formulated as a multi-objective mixed integer linear programming model. By exploiting the advantages of the model, three multi-objective optimization approaches are customized to find highly qualified non-dominated solutions. The effectiveness and efficiency of the approaches are examined both on a hypothetical case and a realistic case.

ACS Style

Jun Zhao; Lixia Huang; Der-Horng Lee; Qiyuan Peng. Improved approaches to the network design problem in regional hazardous waste management systems. Transportation Research Part E: Logistics and Transportation Review 2016, 88, 52 -75.

AMA Style

Jun Zhao, Lixia Huang, Der-Horng Lee, Qiyuan Peng. Improved approaches to the network design problem in regional hazardous waste management systems. Transportation Research Part E: Logistics and Transportation Review. 2016; 88 ():52-75.

Chicago/Turabian Style

Jun Zhao; Lixia Huang; Der-Horng Lee; Qiyuan Peng. 2016. "Improved approaches to the network design problem in regional hazardous waste management systems." Transportation Research Part E: Logistics and Transportation Review 88, no. : 52-75.

Journal article
Published: 01 January 2016 in Transportation Research Record: Journal of the Transportation Research Board
Reads 0
Downloads 0

Agent-based models have gained wide acceptance in transportation planning because with increasing computational power, large-scale people-centric mobility simulations are possible. Several modeling efforts have been reported in the literature on the demand side (with sophisticated activity-based models that focus on an individual’s day activity patterns) and on the supply side (with detailed representation of network dynamics through simulation-based dynamic traffic assignment models). This paper proposes an extension to a state-of-the-art integrated agent-based demand and supply model—SimMobility—for the design and evaluation of autonomous vehicle systems. SimMobility integrates various mobility-sensitive behavioral models in a multiple time-scale structure comprising three simulation levels: ( a) a long-term level that captures land use and economic activity, with special emphasis on accessibility; ( b) a midterm level that handles agents’ activities and travel patterns; and ( c) a short-term level that simulates movement of agents, operational systems, and decisions at a microscopic granularity. In that context, this paper proposes several extensions at the short-term and midterm levels to model and simulate autonomous vehicle systems and their effects on travel behavior. To showcase these features, the first-cut results of a hypothetical on-demand service with autonomous vehicles in a car-restricted zone of Singapore are presented. SimMobility was successfully used in an integrated manner to test and assess the performance of different autonomous vehicle fleet sizes and parking station configurations and to uncover changes in individual mobility patterns, specifically in regard to modal shares, routes, and destinations.

ACS Style

Carlos Lima Azevedo; Katarzyna Marczuk; Sebastian Raveau; Harold Soh; Muhammad Adnan; Kakali Basak; Harish Loganathan; Neeraj Deshmunkh; Der-Horng Lee; Emilio Frazzoli; Moshe Ben-Akiva. Microsimulation of Demand and Supply of Autonomous Mobility On Demand. Transportation Research Record: Journal of the Transportation Research Board 2016, 2564, 21 -30.

AMA Style

Carlos Lima Azevedo, Katarzyna Marczuk, Sebastian Raveau, Harold Soh, Muhammad Adnan, Kakali Basak, Harish Loganathan, Neeraj Deshmunkh, Der-Horng Lee, Emilio Frazzoli, Moshe Ben-Akiva. Microsimulation of Demand and Supply of Autonomous Mobility On Demand. Transportation Research Record: Journal of the Transportation Research Board. 2016; 2564 (1):21-30.

Chicago/Turabian Style

Carlos Lima Azevedo; Katarzyna Marczuk; Sebastian Raveau; Harold Soh; Muhammad Adnan; Kakali Basak; Harish Loganathan; Neeraj Deshmunkh; Der-Horng Lee; Emilio Frazzoli; Moshe Ben-Akiva. 2016. "Microsimulation of Demand and Supply of Autonomous Mobility On Demand." Transportation Research Record: Journal of the Transportation Research Board 2564, no. 1: 21-30.

Proceedings article
Published: 13 July 2015 in CICTP 2015
Reads 0
Downloads 0

As a key component of bus dwell time, passenger movement time in boarding and alighting processes plays an important role in affecting service reliability and service quality. Boarding and alighting processes are impacted by several factors, including vehicle configuration, friction between boarding and alighting passengers, bus floor level, and fare payment methods. The crowding effect refers to the interaction between passengers boarding, alighting, and on-board. In this paper, we introduce two indices, namely rank and occupancy, to describe the crowding effect. Rank reflects the sequence of passengers boarding and alighting, which reveals how passengers’ movement time changes in boarding/alighting process. Occupancy indicates level of crowdedness in vehicle, and quantifies the friction from on board passengers during boarding and alighting process. Based on time-stamped smart card transactions, we measured the inter-tapping interval between two successive boarding (alighting) passengers to identify the effect of rank and occupancy in determining boarding/alighting processes. Before our analysis, a cluster based outlier detection method is applied to guarantee data quality. Using large quantities of boarding/alighting observations from smart card data, we found that both rank and occupancy have strong effects on boarding and alighting processes. For occupancy, 60% is a critical threshold for boarding process, after which a dramatic increase of average boarding time is observed. This research may help better understand the passenger behavior in boarding and alighting processes.

ACS Style

Kangjia Zhao; Lijun Sun; Jian Gang Jin; Der-Horng Lee; Siyu Li. Analysis of Crowding Effect on Passengers’ Movement Time Based on Smart Card Data. CICTP 2015 2015, 1479 -1489.

AMA Style

Kangjia Zhao, Lijun Sun, Jian Gang Jin, Der-Horng Lee, Siyu Li. Analysis of Crowding Effect on Passengers’ Movement Time Based on Smart Card Data. CICTP 2015. 2015; ():1479-1489.

Chicago/Turabian Style

Kangjia Zhao; Lijun Sun; Jian Gang Jin; Der-Horng Lee; Siyu Li. 2015. "Analysis of Crowding Effect on Passengers’ Movement Time Based on Smart Card Data." CICTP 2015 , no. : 1479-1489.

Proceedings article
Published: 13 July 2015 in CICTP 2015
Reads 0
Downloads 0

The application of network science has greatly improved our understanding about the structure and properties of public transport network (PTN). Using tools and methods provided from network science, several standardized representations have been developed and analyzed to understand the topological structure of PTN from different aspects. In this paper, we present an empirical study on the bus network in Singapore. Different from previous studies based on a direct mapping of PTN on road networks, we focus on the weighted C-space representation of public transport networks to better characterize the interaction of different bus services. By exploring the statistical properties of this representation, we find that the bus network in Singapore exhibits similar patterns as many other cities in terms of distributions of edge weight, vertex degree and vertex strength. However, a superlinear scaling is found when we examine the dependency of a vertex’s strength on degree, indicating that PTN in Singapore provides people with more alternatives to travel and transfer. The C-space representation also enables us to further explore the interactions between services by examining the community structure and the corresponding reverse mapping on road networks. This helps us to identify those crucial ‘bridges’ in a city, which is shared by different communities and connect diverse regions.

ACS Style

Lijun Sun; Yang Lu; Der-Horng Lee. Understanding the Structure of Urban Bus Networks: TheC-Space Representation Approach. CICTP 2015 2015, 1557 -1567.

AMA Style

Lijun Sun, Yang Lu, Der-Horng Lee. Understanding the Structure of Urban Bus Networks: TheC-Space Representation Approach. CICTP 2015. 2015; ():1557-1567.

Chicago/Turabian Style

Lijun Sun; Yang Lu; Der-Horng Lee. 2015. "Understanding the Structure of Urban Bus Networks: TheC-Space Representation Approach." CICTP 2015 , no. : 1557-1567.

Proceedings article
Published: 13 July 2015 in CICTP 2015
Reads 0
Downloads 0

Personal rapid transit (PRT) is a new kind of mobility method aiming for sustainable and environmental friendly city development. This automated on-demand public transportation system could be a promising solution for first-mile and last-mile problem of existing public transit network. PRT provides passengers end-to-end service via small autonomous electrical cars operated on a dedicated network of guideway. The performance of this transportation system depends on the framework of guideway network, since the merge and station would lead to vehicles’ delay and queueing. Thus, it’s necessary to evaluate the performance of guideway network in the stage of PRT system planning and design. In this paper, we model the problem of network performance evaluation via Jackson queueing networks. The performances of network are measured by two parameters, namely average queue length and meanwaiting time at each queue. In the case study, these two performance parameters are calculated. This paper provides a straightforward and practical way of PRT guideway network performance evaluation for PRT system planning and design.

ACS Style

Kangjia Zhao; Der-Horng Lee; Jian Gang Jin; Siyu Li. A Queueing Network Based Method for Evaluating Personal Rapid Transit Guideway Network Performance. CICTP 2015 2015, 296 -307.

AMA Style

Kangjia Zhao, Der-Horng Lee, Jian Gang Jin, Siyu Li. A Queueing Network Based Method for Evaluating Personal Rapid Transit Guideway Network Performance. CICTP 2015. 2015; ():296-307.

Chicago/Turabian Style

Kangjia Zhao; Der-Horng Lee; Jian Gang Jin; Siyu Li. 2015. "A Queueing Network Based Method for Evaluating Personal Rapid Transit Guideway Network Performance." CICTP 2015 , no. : 296-307.

Conference paper
Published: 01 July 2015 in 2015 IEEE 7th International Conference on Cybernetics and Intelligent Systems (CIS) and IEEE Conference on Robotics, Automation and Mechatronics (RAM)
Reads 0
Downloads 0

Autonomous mobility on demand (AMOD) has emerged as a promising solution for urban transportation. Compared to prevailing systems, AMOD promises sustainable, affordable personal mobility through the use of self-driving shared vehicles. Our ongoing research seeks to design AMOD systems that maximize the demand level that can be satisfactorily served with a reasonable fleet size. In this paper, we introduce an extension for SimMobility - a high-fidelity agent-based simulation platform - for simulating and evaluating models for AMOD systems. As a demonstration case study, we use this extension to explore the effect of different fleet sizes and stations locations for a station-based model (where cars self-return to stations) and a free-floating model (where cars self-park anywhere). Simulation results for evening peak hours in the Singapore Central Business District show that the free-floating model performed better than the station-based model with a “small number” of stations; this occurred primarily because return legs comprised “empty” trips that did not serve customers but contributed to road congestion. These results suggest that making use of distributed parking facilities to prevent congestion can improve the overall performance of an AMOD system during peak periods.

ACS Style

Katarzyna Anna Marczuk; Harold Soh Soon Hong; Carlos Miguel Lima Azevedo; Muhammad Adnan; Scott Drew Pendleton; Emilio Frazzoli; Der Horng Lee. Autonomous mobility on demand in SimMobility: Case study of the central business district in Singapore. 2015 IEEE 7th International Conference on Cybernetics and Intelligent Systems (CIS) and IEEE Conference on Robotics, Automation and Mechatronics (RAM) 2015, 167 -172.

AMA Style

Katarzyna Anna Marczuk, Harold Soh Soon Hong, Carlos Miguel Lima Azevedo, Muhammad Adnan, Scott Drew Pendleton, Emilio Frazzoli, Der Horng Lee. Autonomous mobility on demand in SimMobility: Case study of the central business district in Singapore. 2015 IEEE 7th International Conference on Cybernetics and Intelligent Systems (CIS) and IEEE Conference on Robotics, Automation and Mechatronics (RAM). 2015; ():167-172.

Chicago/Turabian Style

Katarzyna Anna Marczuk; Harold Soh Soon Hong; Carlos Miguel Lima Azevedo; Muhammad Adnan; Scott Drew Pendleton; Emilio Frazzoli; Der Horng Lee. 2015. "Autonomous mobility on demand in SimMobility: Case study of the central business district in Singapore." 2015 IEEE 7th International Conference on Cybernetics and Intelligent Systems (CIS) and IEEE Conference on Robotics, Automation and Mechatronics (RAM) , no. : 167-172.

Journal article
Published: 19 May 2015 in Transportation
Reads 0
Downloads 0

Daily activity pattern is the reflection and abstraction of actual individual activity participation on daily basis. It carries information on activity type, frequency and sequence. Preference of daily activity patterns varies among population, and thus can be interpreted as personal life styles. This paper advances studies on human daily activity patterns by providing new perspective and methodology in the modeling and learning of daily activity patterns using probabilistic context-free grammars. In this paper, similarities between daily activity pattern—which is defined as activity sequence—and language are explored. We developed context-free grammars to parse and generate daily activity patterns. To replicate people’s heterogeneity in selecting daily activity patterns, we introduced probabilistic context-free grammars and proposed several formulations to estimate the probability of a context-free grammar with daily activity patterns observed in household travel survey. We conducted experiments on the proposed formulations, finding that under proper context-free grammar and problem formulation, the estimated probabilistic context-free grammar is able to reproduce the observed pattern distribution in household travel survey with satisfactory precision. Practically, the proposed methodology sheds light on the issue of generating stochastic and accessibility-dependent choice sets for daily activity pattern models in certain activity-based modeling frameworks.

ACS Style

Siyu Li; Der-Horng Lee. Learning daily activity patterns with probabilistic grammars. Transportation 2015, 44, 49 -68.

AMA Style

Siyu Li, Der-Horng Lee. Learning daily activity patterns with probabilistic grammars. Transportation. 2015; 44 (1):49-68.

Chicago/Turabian Style

Siyu Li; Der-Horng Lee. 2015. "Learning daily activity patterns with probabilistic grammars." Transportation 44, no. 1: 49-68.

Journal article
Published: 01 March 2015 in Transportation Research Part C: Emerging Technologies
Reads 0
Downloads 0
ACS Style

Lijun Sun; Yang Lu; Jian Gang Jin; Der-Horng Lee; Kay W. Axhausen. An integrated Bayesian approach for passenger flow assignment in metro networks. Transportation Research Part C: Emerging Technologies 2015, 52, 116 -131.

AMA Style

Lijun Sun, Yang Lu, Jian Gang Jin, Der-Horng Lee, Kay W. Axhausen. An integrated Bayesian approach for passenger flow assignment in metro networks. Transportation Research Part C: Emerging Technologies. 2015; 52 ():116-131.

Chicago/Turabian Style

Lijun Sun; Yang Lu; Jian Gang Jin; Der-Horng Lee; Kay W. Axhausen. 2015. "An integrated Bayesian approach for passenger flow assignment in metro networks." Transportation Research Part C: Emerging Technologies 52, no. : 116-131.

Journal article
Published: 06 January 2015 in Journal of The Royal Society Interface
Reads 0
Downloads 0

Understanding the long-term impact that changes in a city's transportation infrastructure have on its spatial interactions remains a challenge. The difficulty arises from the fact that the real impact may not be revealed in static or aggregated mobility measures, as these are remarkably robust to perturbations. More generally, the lack of longitudinal, cross-sectional data demonstrating the evolution of spatial interactions at a meaningful urban scale also hinders us from evaluating the sensitivity of movement indicators, limiting our capacity to understand the evolution of urban mobility in depth. Using very large mobility records distributed over 3 years, we quantify the impact of the completion of a metro line extension: the Circle Line (CCL) in Singapore. We find that the commonly used movement indicators are almost identical before and after the project was completed. However, in comparing the temporal community structure across years, we do observe significant differences in the spatial reorganization of the affected geographical areas. The completion of CCL enables travellers to re-identify their desired destinations collectively with lower transport cost, making the community structure more consistent. These changes in locality are dynamic and characterized over short timescales, offering us a different approach to identify and analyse the long-term impact of new infrastructures on cities and their evolution dynamics.

ACS Style

Lijun Sun; Jian Gang Jin; Kay W. Axhausen; Der-Horng Lee; Manuel Cebrian. Quantifying long-term evolution of intra-urban spatial interactions. Journal of The Royal Society Interface 2015, 12, 20141089 .

AMA Style

Lijun Sun, Jian Gang Jin, Kay W. Axhausen, Der-Horng Lee, Manuel Cebrian. Quantifying long-term evolution of intra-urban spatial interactions. Journal of The Royal Society Interface. 2015; 12 (102):20141089.

Chicago/Turabian Style

Lijun Sun; Jian Gang Jin; Kay W. Axhausen; Der-Horng Lee; Manuel Cebrian. 2015. "Quantifying long-term evolution of intra-urban spatial interactions." Journal of The Royal Society Interface 12, no. 102: 20141089.

Journal article
Published: 01 January 2015 in Transportation Research Part E: Logistics and Transportation Review
Reads 0
Downloads 0
ACS Style

Jian Gang Jin; Der-Horng Lee; Hao Hu. Tactical berth and yard template design at container transshipment terminals: A column generation based approach. Transportation Research Part E: Logistics and Transportation Review 2015, 73, 168 -184.

AMA Style

Jian Gang Jin, Der-Horng Lee, Hao Hu. Tactical berth and yard template design at container transshipment terminals: A column generation based approach. Transportation Research Part E: Logistics and Transportation Review. 2015; 73 ():168-184.

Chicago/Turabian Style

Jian Gang Jin; Der-Horng Lee; Hao Hu. 2015. "Tactical berth and yard template design at container transshipment terminals: A column generation based approach." Transportation Research Part E: Logistics and Transportation Review 73, no. : 168-184.

Research article
Published: 01 January 2015 in Transportation Research Record: Journal of the Transportation Research Board
Reads 0
Downloads 0

The path size logit (PSL) aims at capturing correlations between path alternatives by including a correction term, path size, to the multinomial logit (MNL). Several path size formulations have been proposed in the literature and applied to various route choice models extensively in road networks. However, the path size formulation has rarely been studied in the public transport context considering the special characteristics of the public transport network. This paper proposes a new path size formulation for route choice modeling in public transport networks. The new path size formulation accounts for both the correlation attributed to spatial overlapping of path alternatives and the correlation attributed to frequency variations. Direct application of existing path size formation in route choice model estimation and prediction based on smart card data from the Singapore public transport network were used in a comparative analysis of the new path size formulation against an MNL and a base PSL. The results show that the new path size formulation has outperformed other models in both estimation and prediction.

ACS Style

Rui Tan; Muhammad Adnan; Der-Horng Lee; Moshe E. Ben-Akiva. New Path Size Formulation in Path Size Logit for Route Choice Modeling in Public Transport Networks. Transportation Research Record: Journal of the Transportation Research Board 2015, 2538, 11 -18.

AMA Style

Rui Tan, Muhammad Adnan, Der-Horng Lee, Moshe E. Ben-Akiva. New Path Size Formulation in Path Size Logit for Route Choice Modeling in Public Transport Networks. Transportation Research Record: Journal of the Transportation Research Board. 2015; 2538 (1):11-18.

Chicago/Turabian Style

Rui Tan; Muhammad Adnan; Der-Horng Lee; Moshe E. Ben-Akiva. 2015. "New Path Size Formulation in Path Size Logit for Route Choice Modeling in Public Transport Networks." Transportation Research Record: Journal of the Transportation Research Board 2538, no. 1: 11-18.