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Paper

Evaluation of Emissions Reduction in Urban Pickup Systems Heterogeneous Fleet Case Study

 
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Publication: Transportation Research Record: Journal of the Transportation Research Board
Volume: 2224
Pages: 8-16
Publication Date: 2011
Summary:

A case study of the University of Washington Mailing Services, which operates a heterogeneous fleet of vehicles, provides insight into the impact of operational changes on cost, service quality, and emissions. An emissions minimization problem was formulated and solutions were identified with a creation and local search algorithm based on the I1 and 2-opts heuristics.

The algorithm could be used to find many solutions that could improve existing routing on both cost and emissions metrics, reduce emissions by an average of almost 6%, and reduce costs by an average of 9%. More significant cost and emissions savings could be found with service quality reductions. For example, reducing delivery frequency to once a day could lead to emissions and cost savings of close to 35% and 3%, respectively.

Rules of thumb for vehicle assignment within heterogeneous fleets were explored to gain an understanding of simple implementations, such as assigning cleaner vehicles to routes with more customers and longer travel distances.

This case study identified significant emissions reductions that could be obtained with minimal effects on cost and service and that offered new, practical applications that could be used by fleet managers interested in reducing their carbon footprint.

Authors: Dr. Anne Goodchild, Kelly Pitera, Felipe Sandoval
Recommended Citation:
Pitera, Kelly, Felipe Sandoval, and Anne Goodchild. "Evaluation of Emissions Reduction in Urban Pickup Systems: Heterogeneous Fleet Case Study." Transportation Research Record 2224, no. 1 (2011): 8-16. 
Paper

COVID-19 Impacts on Online and In-Store Shopping Behaviors: Why they Happened and Whether they Will Last Post Pandemic

 
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Publication:  Transportation Research Record: Journal of the Transportation Research Board
Publication Date: 2023
Summary:

Throughout the COVID-19 pandemic, online and in-store shopping behaviors changed significantly. As the pandemic subsides, key questions are why those changes happened, whether they are expected to stay, and, if so, to what extent. We answered those questions by analyzing a quasi-longitudinal survey dataset of the Puget Sound residents (Washington, U.S.). We deployed structural equation modeling (SEM) to build separate models for food, grocery, and other items shopping to explore the factors affecting such changes. The results revealed that people’s online and in-store shopping frequencies during the pandemic were affected by their perceived health risks, attitudes toward shopping, and pre-pandemic shopping frequencies. Similarly, it was shown that how frequently people expect to shop post pandemic is influenced by their attitudes toward shopping, changes during the pandemic, and their pre-pandemic frequencies. We also classified respondents into five groups, based on their current and expected future shopping behavior changes, and performed a descriptive analysis. The five groups—Increasers, Decreasers, Steady Users, Returnees, and Future Changers—exhibited different trends across online and in-store activities for shopping different goods. The analysis results showed that, while 25% of the respondents increased their online shopping, only 8% to 13% decreased their in-store activities, implying that online shopping did not completely substitute in-store shopping. Moreover, we found that online shopping is a substitution for in-store shopping for groceries, while it complements in-store shopping for food and other items. Additionally, more than 75% of new online shoppers expect to keep purchasing online, while 63%–85% of in-store Decreasers plan to return to their pre-pandemic frequencies.

The rise of e-commerce, busy lifestyles, and the convenience of next- and same-day home deliveries have resulted in exponential growth of online shopping in the U.S., rising from 5% of the total retail in 2011 to 15% in 2020, and it is expected to grow even further in the future. Worldwide, spending on e-commerce passed $4.9 trillion in 2021 and it is projected to surge to $7 trillion by 2025.

In the past few years, there has been ongoing research on how this growth would change people’s travel patterns and whether its effect on in-person activities would be substitution, complementing, or modification. However, there is no single answer to this question, given different product types, regions, demographics, and primary travel modes.

While online purchasing had already been experiencing a growth every year before 2020, the pandemic accelerated this trend. In 2020, online shopping constituted more than 20% of total spending on consumer goods worldwide in comparison to 16.4% in 2019 and 14.4% in 2018. Before COVID-19, it was predicted that total e-commerce sales in the U.S. would grow up to $674.88 billion, yet the actual number turned out to be $799.18 billion. With a 15.9% growth, the U.S. is among the top 10 countries with the highest growth rate in online retail shopping in 2022.

Embracing digital technologies and bringing shops into homes are among the immediate impacts of the pandemic restrictions and lockdowns, with the majority of people reducing their frequency of going to stores and adopting alternative shopping approaches such as curbside pick-up and home delivery. Based on the reports by the U.S. Bureau of Transportation Statistics (BTS), in Nov–Dec 2020, when the penetration of the coronavirus reached its first peak in the U.S., the percentage of people who decided to shop online instead of going to stores increased by up to 10%. During the early pandemic, about 35% of U.S. workers switched to remote working, and from March to April 2020, the average daily number of people staying home increased by 32 million and the total number of trips decreased by 2.5B. Dining-in restaurants were also banned in half of the U.S. states for several months in 2020, which resulted in a significant drop in the restaurant dine-in demand and shifted people toward online food delivery services, and buying groceries online rather than going to store.

These changes were also influenced by socio-demographic characteristics. For instance, according to the BTS, the percentage of people with an annual income close to $125,000 who replaced their in-store shopping by online shopping in Nov–Dec 2020 was twice those with an annual income of $25,000. People in the neighborhoods with higher number of positive COVID-19 cases or higher spread rate of positive new cases were more likely to change their in-store shopping to online-shopping. Senior people were also shown to have higher tendency to shop online compared with younger generations, perhaps because of health and safety concerns. It is worth noting that these changes were not the same across all products; for example, online sales of food and beverage in the U.S. doubled in 2020, while home furniture online sales only increased by about 50%.

Another factor that is proved to have a major effect on people’s shopping behaviors and travel patterns during the pandemic is their risk perception and fears for their health. Irawan et al. found that perceiving COVID-19 as a severe disease decreased people’s tendency to do in-store grocery shopping. Similarly, Moon et al. found out that, during the pandemic, people who considered themselves less vulnerable to the infection were less likely to use online channels for shopping. Several studies have mentioned that the perceived health risk varies among different groups of population and depends on region, age, gender, education, race, and marital status.

Moreover, people’s online and in-store shopping behaviors are affected by their socio-demographic factors and their attitudes toward the activity. The advantages and disadvantages of online shopping over in-store shopping play a role in attitudes toward the activity. The advantages, such as receiving goods without leaving home, having access to a wider variety of products and information, and being able to compare them easily and efficiently, result in a positive attitude toward online shopping, especially during the pandemic given high perceived health risk, formal penalties, or both. On the other hand, online shopping has some disadvantages, such as transaction security concerns and long delivery times, and in-store shopping offers specific benefits, such as the ability to see, touch, feel, and try the products, ensuring the store’s environment quality, immediate possession of the product, social interaction, and entertainment. Therefore, even during the pandemic, some people maintained frequent in-store shopping trips.

Whether the pandemic-induced changes in online and in-store shopping are permanent is still debatable. Sheth discussed that people may find the new routine more convenient, affordable, and accessible, and therefore stick to it even after the pandemic is over. On the contrary, Dannenberg et al. argued that people’s motives to shop online only hold for the time of crisis, and online retailing will decline when circumstances change. Watanabe and Omori showed that most people used to shop online long before the pandemic, and they merely increased their frequency because of infection risk. So, the reasons behind the surge in online shopping might dissipate as COVID-19 recedes.

In this paper, we study how online and in-store shopping behaviors for different goods were affected during COVID-19, and whether those changes are expected to stay post pandemic. We analyze a quasi-longitudinal survey dataset from the Puget Sound region in Washington State, U.S., that includes data on people’s shopping behavior before and during pandemic, as well as their expected shopping behavior after pandemic. The dataset also contains information on socio-demographic characteristics, as well as psychometric questions about COVID-19 risk perception and attitudes toward shopping. Through descriptive analysis and structural equation modeling (SEM), we explore the factors that directly or indirectly affected people’s three shopping activities (online and in-store), for food, grocery, and other items (clothing, home goods, etc.), and investigate the similarities and differences amongst them.

This study is distinguished in several ways from the previous ones that investigated the impacts of COVID-19 on people’s shopping behavior: (1) it applies a unique descriptive analysis by classifying respondents based on their current and expected future shopping trends and studies how socio-demographic characteristics (directly and indirectly) influence people’s shopping behaviors by analyzing the similarities and differences between those groups; (2) it models online and in-store shopping jointly, considering covariations and dependencies between those two modes; (3) it applies the same methodology and set of variables to three different shopping activities (for food, grocery, and other items) and compares and contrasts their observed/expected trends and influencing factors; and (4) in addition to socio-demographic and attitudinal variables, it considers people’s baseline shopping behaviors (how frequently they shopped online and in-store before the pandemic) as factors affecting their expected post-pandemic shopping behaviors.

Authors: Dr. Andisheh Ranjbari, Jorge Manuel Diaz-Gutierrez (Pennsylvania State University, Helia Mohammadi-Mavi (Pennsylvania State University)
Recommended Citation:
Diaz-Gutierrez, J. M., Mohammadi-Mavi, H., & Ranjbari, A. (2023). COVID-19 Impacts on Online and In-Store Shopping Behaviors: Why they Happened and Whether they Will Last Post Pandemic. Transportation Research Record: Journal of the Transportation Research Board, 036119812311551. https://doi.org/10.1177/03611981231155169 
Paper

Data Stories from Urban Loading Bays

 
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Publication: European Transport Research Review
Volume: 9
Publication Date: 2017
Summary:

Freight vehicle parking facilities at large urban freight traffic generators, such as urban retail malls, are often characterized by a high volume of vehicle arrivals and a poor parking supply infrastructure. Recurrent congestion of freight parking facilities generates environmental (e.g. pollution), economic (e.g. delays in deliveries), and freight and social (e.g. traffic) negative externalities. Solutions aimed at either improving or better managing the existing parking infrastructure rely heavily on data and data-driven models to predict their impact and guide their implementation. In the current work, we provide a quantitative study of the parking supply and freight vehicle drivers’ parking behavior at urban retail malls.

We use as case studies two typical urban retail malls located in Singapore, and collect detailed data on freight vehicles delivering or picking up goods at these malls. Insights from this data collection effort are relayed as data stories. We first describe the parking facility at a mall as a queueing system, where freight vehicles are the agents and their decisions are the parking location choice and the parking duration.

Using the data collected, we analyze (i) the arrival rates of vehicles at the observed malls, (ii) the empirical distribution of parking durations at the loading bays, (iii) the factors that influence the parking duration, (iv) the empirical distribution of waiting times spent by freight vehicle queueing to access the loading bay, and (v) the driver parking location choices and how this choice is influenced by system congestion.

This characterization of freight driver behavior and parking facility system performance enables one to understand current challenges, and begin to explore the feasibility of freight parking and loading bay management solutions.

Authors: Dr. Giacomo Dalla Chiara, Lynette Cheah
Recommended Citation:
Dalla Chiara, G., Cheah, L. Data stories from urban loading bays. Eur. Transp. Res. Rev. 9, 50 (2017). https://doi.org/10.1007/s12544-017-0267-3
Paper

Network Design with Elastic Demand and Dynamic Passenger Assignment to Assess the Performance of Transit Services

 
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Publication: Journal of Transportation Engineering, Part A: Systems
Volume: 146:05:00
Publication Date: 2020
Summary:

This study proposes a solution framework for operational analysis and financial assessment of transit services that considers the passenger behavior and the elasticity of transit demand to service characteristics. The proposed solution framework integrates a dynamic transit passenger assignment model (Fast-Trips) with a mode choice model and a service design module, and iterates these methods until an equilibrium between fares and frequencies is reached. The solution framework was implemented for a newly conceived intercity transit service in Arizona, and the system performance was studied for multiple fare policy and frequency design scenarios. The results showed that the scenarios with designed-oriented frequencies had lower ratios of revenue to operating cost (R/C) compared with those in which frequencies were set based on the passenger path-choice behaviors and route usage, which emphasizes the importance of considering elastic transit demand in network and service designs. The sensitivity analysis also indicated that there are multiple ways to achieve a certain R/C ratio, and therefore it is the other objectives and the operator’s priorities that define the final design and service characteristics.

Authors: Dr. Andisheh Ranjbari, Mark Hickman, Yi-Chang Chiu
Recommended Citation:
Ranjbari, A., Hickman, M., & Chiu, Y. C. (2020). Network Design with Elastic Demand and Dynamic Passenger Assignment to Assess the Performance of Transit Services. Journal of Transportation Engineering, Part A: Systems, 146(5), 04020030. https://doi.org/10.1061/jtepbs.0000326.
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

Rails-Next-to-Trails: A Methodology for Selecting Appropriate Safety Treatments at Complex Multimodal Intersections

 
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Publication: Transportation Research Record: Journal of the Transportation Research Board
Volume: 2672 (10)
Pages: 27-Dec
Publication Date: 2018
Summary:

There are more than 212,000 at-grade railroad crossings in the United States. Several feature paths running adjacent to the railroad tracks, and crossing a highway; they serve urban areas, recreational activities, light rail station access, and a variety of other purposes. Some of these crossings see a disproportionate number of violations and conflicts between rail, vehicles, and pedestrians and bikes. This research focuses on developing a methodology for appropriately addressing the question of treatments in these complex, multimodal intersections. The methodology is designed to be able to balance a predetermined, prescriptive approach with the professional judgment of the agency carrying out the investigation. Using knowledge and data from the literature, field studies, and video observations, a framework for selecting treatments based on primary issues at a given location is developed. Using such a framework allows the agency to streamline their crossing improvement efforts; to easily communicate and inform the public of the decisions made and their reasons for doing so; to secure stakeholder buy-in prior to starting a project or investigation; to make sure that approach and selected treatments are more standardized; and to ensure transparency in the organization to make at-grade crossings safer for pedestrians and bicyclists, without negatively impacting trains or vehicles.

Recommended Citation:
Alligood, Anna & Sheth, Manali & Goodchild, Anne & McCormack, Edward & Butrina, Polina. (2018). Rails-Next-to-Trails: A Methodology for Selecting Appropriate Safety Treatments at Complex Multimodal Intersections. Transportation Research Record: Journal of the Transportation Research Board, 2672(10), 12–27. https://doi.org/10.1177/0361198118792763
Paper

Evaluating Global Positioning System (GPS) Data Usability for Freight Performance Measures

Publication: Transportation Research Board 96th Annual Meeting - Transportation Research Board
Volume: 17-04053
Publication Date: 2017
Summary:

Freight Performance Measures (FPM) are of interest to transportation planning agencies. One of the key tools that aids in the study of freight system activity is the data from Global Positioning System (GPS) devices located in trucks and cars. While commercially available GPS data has a common basic output format, the level of aggregation of the raw data, impacts the data’s ultimate usability and applications. This paper categorizes the different level of GPS data – from raw to highly aggregate and highlights the different strength, weakness, and applications of the data. Based on the insights learned from previous studies related to GPS data types, the authors make recommendations for how to match the GPS data to different analytical needs.

Recommended Citation:
Sankarakumaraswamy, Saravanya. Edward McCormack, Anne Goodchild, and Mark Hallenbeck. Evaluating Global Positioning System (GPS) Data Usability for Freight Performance Measures. No. 17-04053. 2017. 
Paper

Identifying Truck Route Choice Priorities: The Implications for Travel Models

Publication: Transportation Letters
Volume: 6 (2)
Pages: 98-106
Publication Date: 2014
Summary:

This article identifies the truck routing priorities of freight companies through a survey of Washington state shippers, carriers, and receivers. To elicit these priorities, the survey prompted the respondents to rate 15 items believed to affect route choice decision making with respect to each item’s influence on route choice. Item response theory (IRT) and latent class analysis (LCA) highlights priorities that were common among all survey respondents and priorities that were different among the sample.

Minimizing cost and meeting customer requirements were priorities for all. The influence of other items such as road grade, hours of service limits, and driver availability depended on whether the respondent was best described as a long-haul, local-regional, or urban trucking provider. These three classes of companies were derived from the LCA, and each class has a distinct response pattern to the 15 routing items. This result suggests that truck routing priorities are not constant and uniform across a state’s trucking industry but rather variable and largely dependent on trip length. The paper concludes with practical recommendations as to how these priorities can be implemented within a truck routing model.

Authors: Dr. Anne Goodchild, Maura Rowell, Andrea Gagliano
Recommended Citation:
Rowell, Maura, Andrea Gagliano, and Anne Goodchild. "Identifying Truck Route Choice Priorities: The Implications for Travel Models." Transportation Letters 6, no. 2 (2014): 98-106. 
Paper

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

 
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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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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.