Paper

Double-Cycling Strategies for Container Ships and Their Effect on Ship Loading and Unloading Operations

URL: https://doi.org/10.1287/trsc.1060.0148

Publication: Transportation Science

Volume: 40(4)

Pages: 473-483

Publication Date: 2006

Summary:

Loading ships as they are unloaded (double cycling) can improve the efficiency of a quay crane and container port. This paper describes the double-cycling problem, and presents solution algorithms and simple formulae to determine reductions in the number of operations and operating time using the technique. We focus on reducing the number of operations necessary to turn around a row of a ship. The problem is first formulated as a scheduling problem, which can be solved optimally. A simple lower bound for all strategies is then developed. We also present a greedy algorithm that yields a simple and tight upper bound. The gap between the upper and lower bounds is so small that the formula for either bound is an accurate predictor of crane performance. The analysis is then extended to double cycling when ships have deck hatches. Results are presented for many simulated vessels, and compared to empirical data from a real-world trial. The research demonstrates that double cycling can create significant efficiency gains in crane productivity, typically reducing the number of cycles by about 20% and the operational time by about 10% when double cycling only below deck.

Authors: Dr. Anne Goodchild, C. Daganzo

Recommended Citation:
Goodchild, Anne V., and Carlos F. Daganzo. "Double-Cycling Strategies for Container Ships and Their Effect on Ship Loading and Unloading Operations." Transportation Science 40, no. 4 (2006): 473-483.

Paper

Estimating Intermodal Transfer Barriers to Light Rail using Smartcard Data in Seattle, WA

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URL: https://doi.org/10.1177/03611981221119190

Publication: Transportation Research Record: Journal of the Transportation Research Board

Publication Date: 2022

Summary:

Transit transfers are a necessary inconvenience to riders. They support strong hierarchical networks by connecting various local, regional, and express lines through a variety of modes. This is true in Seattle, where many lines were redrawn to feed into the Link Light Rail network. Previous transfer studies, using surveys, found that perceived safety, distance, and personal health were significant predictors of transfers. This study aims to use smartcard data and generalized linear modeling to estimate which elements of transfers are commonly overcome—and which are not—among riders boarding the Link Light Rail in Seattle and its suburbs. The aims of this research are twofold: (1) critical analysis of attributes of transfer barriers so that the future station area could serve improved riders’ accessibility; (2) equity of transfer barriers among the users by analyzing the user breakdown of the origin lines and the destination. We use Seattle’s One Regional Card for All smartcard data among the Link Light Rail riders in the Seattle metropolitan area in 2019, and applied a negative binomial generalized linear model. The model suggests that walking distance and walking grade have significant effects on transfers. For the users’ equity analysis, the disabled population tends to transfer less, while the low-income and youth riders populations tend to transfer more often. Future research could incorporate a more mixed-methods approach to confirm some of these findings or include station amenities, such as live schedule updates for common transfer lines.

Authors: Dr. Ed McCormack, James Eager (University of Washington Department of Urban Design and Planning), Chang-Hee Christine Bae (University of Washington Department of Urban Design and Planning)

Recommended Citation:
Eager, J., Bae, C.-H. C., & McCormack, E. D. (2022). Estimating Intermodal Transfer Barriers to Light Rail using Smartcard Data in Seattle, WA. Transportation Research Record. https://doi.org/10.1177/03611981221119190.

Paper

Modeling the Competing Demands of Carriers, Building Managers, and Urban Planners to Identify Balanced Solutions for Allocating Building and Parking Resources

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URL: https://doi.org/10.1016/j.trip.2022.100656

Publication: Transportation Research Interdisciplinary Perspectives

Volume: 15

Publication Date: 2022

Summary:

While the number of deliveries has been increasing rapidly, infrastructure such as parking and building configurations has changed less quickly, given limited space and funds. This may lead to an imbalance between supply and demand, preventing the current resources from meeting the future needs of urban freight activities.

This study aimed to discover the future delivery rates that would overflow the current delivery systems and find the optimal number of resources. To achieve this objective, we introduced a multi-objective, simulation-based optimization model to define the complex freight delivery cost relationships among delivery workers, building managers, and city planners, based on the real-world observations of the final 50 feet of urban freight activities at an office building in downtown Seattle, Washington, U.S.A.

Our discrete-event simulation model with increasing delivery arrival rates showed an inverse relationship in costs between delivery workers and building managers, while the cost of city planners decreased up to ten deliveries/h and then increased until 18 deliveries/h, at which point costs increased for all three parties and overflew the current building and parking resources. The optimal numbers of resources that would minimize the costs for all three parties were then explored by a non-dominated sorting genetic algorithm (NSGA-2) and a multi-objective, evolutionary algorithm based on decomposition (MOEA/D).

Our study sheds new light on a data-driven approach for determining the best combination of resources that would help the three entities work as a team to better prepare for the future demand for urban goods deliveries.

Authors: Haena KimDr. Anne Goodchild, Linda Boyle

Recommended Citation:
Kim, H., Goodchild, A., & Boyle, L. N. (2022). Modeling The Competing Demands Of Carriers, Building Managers, And Urban Planners To Identify Balanced Solutions For Allocating Building And Parking Resources. In Transportation Research Interdisciplinary Perspectives (Vol. 15, p. 100656). Elsevier BV. https://doi.org/10.1016/j.trip.2022.100656

Paper

Challenges in Credibly Estimating the Travel Demand Effects of Mobility Services

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URL: https://doi.org/10.1016/j.tranpol.2021.02.001

Publication: Transport Policy

Volume: 103

Pages: 224-235

Publication Date: 2021

Summary:

Mobility services including carsharing and transportation network company (TNC) services have been growing rapidly in North America and around the world. Measuring the effects of these services on traveler behavior is challenging because the results of any such analysis are sensitive to how (1) outcomes are measured and (2) counterfactuals are constructed. The lack of good control groups or randomization of assignment leaves lingering uncertainty over the contributions of selection bias and treatment effects to reported differences in travel behavior between users and non-users of these services. This paper reports on two approaches for measuring the effects of mobility service adoption on travel rate and car ownership. We first tried a pretest-posttest randomized encouragement experiment to deal with the shortcomings of poor control groups. Then, we turned to the approach of self-reported effects based on hypothetical controls to investigate whether variations in survey question presentation could influence respondents’ answers and thus lead to changes in estimated effects. The data to conduct this study came from two sources: a panel survey administered by the authors at the University of Washington (UW), and a survey by Populus Technologies, Inc. (Populus). Various statistical tests were applied to analyze the data, and the results highlight the pivotal role that the research design plays in influencing the outcomes, and manifest the fundamental challenge of establishing credible estimates of the causal effects of adopting mobility services on travel behaviors.

Authors: Dr. Andisheh Ranjbari, Xiao Wen, Fan Qi, Regina R. Clewlow, Don MacKenzie

Recommended Citation:
Xiao Wen, Andisheh Ranjbari, Fan Qi, Regina R. Clewlow, Don MacKenzie. Challenges in credibly estimating the travel demand effects of mobility services. Transport Policy, (103:224-235) 2021. https://doi.org/10.1016/j.tranpol.2021.02.001.

Paper

Evaluating the Use of Electronic Door Seals (E-Seals) on Shipping Containers

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Publication: International Journal of Applied Logistics

Volume: 1(4)

Pages: 13-20

Publication Date: 2010

Summary:

Electronic door seals (E-seals) were tested on shipping containers that traveled through ports, over borders, and on roadways. The findings showed that using these RFID devices could increase supply chain efficiency and improve the security of containerized cargo movements, particularly when E-seals replace common mechanical seals. Before the benefits of E-seals can be realized, several barriers must be addressed. A major problem has been a lack of frequency standards for E-seals, hindering their acceptability for global trade. Routine use of E-seals would also require new processes that might slow their acceptance by the shipping industry. Disposable E-seals, which decrease industry concerns about costs and enforcement agency concerns about security by eliminating the need to recycle E-seals, are not common because they need to be manufactured in large quantities to be cost effective. Compatibility with existing highway systems could also promote E-seal acceptance, as containers could be tracked on roadways.

Authors: Dr. Ed McCormack, Mark Jensen, Al Hovde

Recommended Citation:
McCormack, E., Jensen, M., & Hovde, A. (2010). Evaluating the Use of Electronic Door Seals (E-Seals) on Shipping Containers. International Journal of Applied Logistics (IJAL), 1(4), 13-29.

Paper

The Effect of Distance on Cargo Flows: A Case Study of Chinese Imports and Their Hinterland Destinations

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URL: https://doi.org/10.1057/s41278-017-0079-3

Publication: Maritime Economics & Logistics

Volume: 20

Pages: 456-475

Publication Date: 2018

Summary:

With the rapid development of ports in China, competition for cargo is growing. The ability of a port to attract hinterland traffic is affected by many factors, including distance to the hinterland destinations. This paper studies the effects of distance on import cargo flows from a port to its hinterland. Two major findings are reported. Through a Spatial Concentration Analysis, this study shows that cargo imported through ports with relatively low throughput is primarily delivered to local areas, with the proportion of cargo delivered to local areas from larger ports being much smaller. The present study also shows (according to a gravity model, the Gompertz function and several other methods) that cargo flows from a large port to its hinterland increase with distance below a certain threshold, while cargo flows approach a stable state once they exceed this threshold. These results can be used to inform port managers and policy makers regarding the hinterland markets for ports of different sizes.

Authors: Dr. Anne Goodchild, Likun Wang, Yong Wang

Recommended Citation:
Wang, Likun, Anne Goodchild, and Yong Wang. (2017) The Effect of Distance on Cargo Flows: A Case Study of Chinese Imports and Their Hinterland Destinations. Maritime Economics & Logistics, 20(3), 456–475. https://doi.org/10.1057/s41278-017-0079-3

Paper

Effect of Tsunami Damage on Passenger and Forestry Transportation in Pacific County Washington

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URL: https://doi.org/10.3141/2604-11

Publication: Transportation Research Record: Journal of the Transportation Research Board

Volume: 2604 (1)

Pages: 88-94

Publication Date: 2017

Summary:

The outer coast of Washington State is exposed to significant seismic and tsunami hazards. A Cascadia Subduction Zone (CSZ) event is expected to cause high earthquake intensities and tsunami inundation resulting in considerable infrastructure loss, inundation of developed land, and degraded functioning of coastal communities.

One area of particular concern is Pacific County, located in southwest Washington, where over 85% of the population is expected to experience severe shaking intensities.

This paper establishes the pre-disaster passenger and freight transportation patterns and the damaged post-disaster road network in Pacific County. The hazard used in the analysis is the CSZ magnitude 9.1 earthquake and resulting tsunami. Passenger travel is compared to forestry travel along the following characteristics: overall change in travel distance, percentage of trips that are longer, the percentage of trips that are no longer possible, and the distributions of travel distance.

Because passenger and freight travel have different purposes and patterns, understanding how they are affected differently can serve as a foundation for community-based disaster recovery planning to increase community resilience to earthquakes and tsunamis.

Authors: Dr. Anne Goodchild, Maura Rowell

Recommended Citation:
Rowell, Maura, and Anne Goodchild. "Effect of Tsunami Damage on Passenger and Forestry Transportation in Pacific County, Washington." Transportation Research Record 2604, no. 1 (2017): 88-94.

Paper

Logistics Sprawl: Differential Warehousing Development Patterns in Los Angeles and Seattle

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URL: https://doi.org/10.3141/2410-12

Publication: Transportation Research Record: Journal of the Transportation Research Board

Volume: 2410

Pages: 105-112

Publication Date: 2014

Summary:

The warehousing industry experienced a period of rapid growth from 1998 to 2009. This paper compares how the geographic distribution of warehouses changed in both the Los Angeles and Seattle Metropolitan Areas over that time period. These two west coast cities were chosen due to their geographic spread and proximity to major ports as well as their difference in size. The phenomenon of logistics sprawl, or the movement of logistics facilities away from urban centers, which has been demonstrated in past research for the Atlanta and Paris regions, is examined for these two areas. The weighted geometric center of warehousing establishments was calculated for both areas for both years, along with the change in the average distance of warehouses to that center, an indicator of sprawl. We find that between 1998 and 2009, warehousing in Los Angeles sprawled considerably, with the average distance increasing from 25.91 to 31.96 miles, an increase of over 6 miles. However in Seattle, the region remained relatively stable, showing a slight decrease in average distance from the geographic center. Possible explanations for this difference are discussed.

Authors: Dr. Anne Goodchild, Laetitia Dablanc, Scott Ogilvie

Recommended Citation:
Dablanc, Laetitia, Scott Ogilvie, and Anne Goodchild. "Logistics sprawl: differential warehousing development patterns in Los Angeles, California, and Seattle, Washington." Transportation Research Record 2410, no. 1 (2014): 105-112.

Paper

Crane Double-Cycling in Container Ports: Planning Methods and Evaluation

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URL: https://doi.org/10.1016/j.trb.2007.02.006

Publication: Transportation Research Part B: Methodological

Volume: 41(8)

Pages: 875-891

Publication Date: 2007

Summary:

The Clean Trucks Program is a Clean Air Action Plan initiative currently being adopted by the Ports of Los Angeles and Long Beach. This paper examines the Clean Trucks Program’s current requirements and estimates the impact on terminal operations. Using terminal operations data supplied by three terminal operating companies, we conduct a simple queuing analysis and present a regression model that allows us to consider the potential impact of the policy changes.

While this paper does not estimate the impact at a specific terminal, we consider order of magnitude effects. While the program itself does not require terminal operations changes, the program will modestly increase incentives to improve operational efficiency outside the terminal and reduce terminal gate processing time. It will also require technology that could be used for further operational changes.

We show, however, that unless gate time improvements are matched with these operational improvements in the terminal, they will only move the delay inside the terminal and not reduce total terminal time.

Our research considers the impact of the Clean Trucks Program on the Ports of Los Angeles and Long Beach, but similar concerns are driving changes at ports around the globe.

Authors: Dr. Anne Goodchild, C.F. Daganzo

Recommended Citation:
Goodchild, A.V., and C.F. Daganzo. “Crane Double Cycling in Container Ports: Planning Methods and Evaluation.” Transportation Research Part B: Methodological, vol. 41, no. 8, 2007, pp. 875–891., doi:10.1016/j.trb.2007.02.006.

Paper

A Meta-Heuristic Solution Approach to Isolated Evacuation Problems

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URL: https://doi.org/10.1109/WSC57314.2022.10015470

Publication: IEEE (Institute of Electrical and Electronics Engineers)

Volume: 2022 Winter Simulation Conference (WSC) INFORMS

Publication Date: 2022

Summary:

This paper provides an approximation method for the optimization of isolated evacuation operations, modeled through the recently introduced Isolated Community Evacuation Problem (ICEP). This routing model optimizes the planning for evacuations of isolated areas, such as islands, mountain valleys, or locations cut off through hostile military action or other hazards that are not accessible by road and require evacuation by a coordinated set of special equipment. Due to its routing structure, the ICEP is NP-complete and does not scale well. The urgent need for decisions during emergencies requires evacuation models to be solved quickly. Therefore, this paper investigates solving this problem using a Biased Random-Key Genetic Algorithm. The paper presents a new decoder specific to the ICEP, that allows to translate in between an instance of the S-ICEP and the BRKGA. This method approximates the global optimum and is suitable for parallel processing. The method is validated through computational experiments.

Authors: Dr. Anne GoodchildFiete Krutein, Linda Ng Boyle (University of Washington Dept. of Industrial & Systems Engineering)

Recommended Citation:
K. F. Krutein, L. N. Boyle and A. Goodchild, "A Meta-Heuristic Solution Approach to Isolated Evacuation Problems," 2022 Winter Simulation Conference (WSC), Singapore, 2022, pp. 2002-2012, doi: 10.1109/WSC57314.2022.10015470.