Paper

Ecommerce and Logistics Sprawl: A Spatial Exploration of Last-Mile Logistics Platforms

URL: https://doi.org/10.1016/j.jtrangeo.2023.103692

Publication: Journal of Transport Geography

Volume: 112

Publication Date: 2023

Summary:

The rise of ecommerce helped fuel consumer appetite for quick home deliveries. One consequence has been the placing of some logistics facilities in proximity to denser consumer markets. The trend departs from prevailing discussion on “logistics sprawl,” or the proliferation of warehousing into the urban periphery. This study spatially and statistically explores the facility- and region-level dimensions that characterize the centrality of ecommerce logistics platforms. Analyzing 910 operational Amazon logistics platforms in 89 U.S. metropolitan statistical areas (MSAs) between 2013 and 2021, this study estimates temporal changes in distances to relative, population centroids and population-weighted market densities. Results reveal that although some platforms serving last-mile deliveries are located closer to consumers than upstream distribution platforms to better fulfill time demands, centrality varies due to facility operating characteristics, market size, and when the platform opened.

Ecommerce has transformed the “consumption geography” of cities. These transformations have major implications for shopping behaviors and retail channels, last-mile operations and delivery mode choice, the management and pricing of competing uses for street and curb space, and the spatial ordering and functional role of logistics land uses. In the latter case, researchers have observed a diversification of logistics platforms to more efficiently serve home delivery demand. These platforms range from “dark stores” and “microfullfilment centers” that fulfill on-demand deliveries and omni-channeled retail without a consumer facing storefront, multi-use urban distribution centers that convert unproductive sites (e.g., abandoned rail depots) to more lucrative land uses, and “microhubs” that stage transloading between cargo vans and e-bicycles suited for dense urban neighborhoods.

Logistics spaces play an important role in improving urban livability and environmental sustainability. Planning decisions scale geographically from the region-level to the curb. Facilities such as urban consolidation centers and loading zones can mitigate common delivery inefficiencies, such as low delivery densities and “cruising” for parking, respectively. These inefficiencies generate many negative externalities including climate emissions, air and noise pollution, congestion, and heightened collision risks, especially for vulnerable road users such as pedestrians and bicyclists. Limited commercial data has made it difficult, however, to observe spatial patterns with regards to ecommerce logistics platforms.

Using detailed proprietary data, this paper explores the evolving spatial organization of ecommerce logistics platforms. Given the company’s preeminence as the leading online retailer in the U.S., the paper presents Amazon as a case study for understanding warehousing and distribution (W&D) activity in the larger ecommerce space. Utilizing proprietary data on Amazon logistics facilities between 2013 and 2021, this research explores the geographic shape and explanatory dimensions of ecommerce within major U.S. metropolitan areas. In the following section, this study defines the state of research related to broader W&D land use and its implications to ecommerce’s distinct consumption geography. Afterwards, two methodologies for measuring logistics centrality are tested: a temporally relative barycenter-based metric, the prevailing method in literature, and another GIS-based, population-weighted service distance metric. The two measurements reveal nuances between facility- and region-level differences in the spatial organization of ecommerce platforms, which has yet to be fully researched. After presenting results from an exploratory regression analysis, this study discusses implications for future urban logistics land use and transport decisions.

Authors: Travis FriedDr. Anne Goodchild

Recommended Citation:
Fried, T., & Goodchild, A. (2023). E-commerce and logistics sprawl: A spatial exploration of last-mile logistics platforms. Journal of Transport Geography, 112, 103692. https://doi.org/10.1016/j.jtrangeo.2023.103692

Paper

Seeking Equity and Justice in Urban Freight: Where to Look?

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URL: https://doi.org/10.1080/01441647.2023.2247165

Publication: Transport Reviews

Publication Date: 2023

Summary:

What do equity and social justice mean for urban freight planning and management? New Urban Freight Lab paper reviews transportation and mobility justice theory and finds that urban freight issues are absent from these discussions, which primarily concern passenger and personal mobility. When urban freight is considered, authors usually discuss topics such as emissions, pollution, congestion, noise, and collisions. This paper looks more in-depth at urban freight justice, including access to essential goods, community governance, employment opportunities and barriers, and regional and global perspectives.

Urban freight systems embed and reflect spatial inequities in cities and imbalanced power structures within transport decision-making. These concerns are principal domains of “transportation justice” (TJ) and “mobility justice” (MJ) scholarship that have emerged in the past decade. However, little research exists situating urban freight within these prevailing frameworks, which leaves urban freight research on socio-environmental equity and justice ill-defined, especially compared to passenger or personal mobility discussions. Through the lens that derives from TJ and MJ’s critical dialogue, this study synthesizes urban freight literature’s engagement with equity and justice.

Namely, the review evaluates:

How do researchers identify equitable distributions of urban freight’s costs and benefits?
At what scale do researchers evaluate urban freight inequities?
And who does research consider entitled to urban freight equity and how are they involved in urban freight governance?

The findings help inform researchers who seek to reimagine urban freight management strategies within broader equity and justice discourse.

Decades-long growth in urbanization and the more recent surge in e-commerce have spurred concerns around the uneven impacts of freight’s swelling urban footprint. Transport scholars note increasing conflicts between freight vehicles and vulnerable road users, like bicyclists and pedestrians in dense urban areas. Meanwhile, environmental justice (EJ) scholars have long measured unequal exposure to freight traffic pollution along socio-economic and ethnic lines.

However, relatively few urban freight studies engage with social equity. Those that do usually avoid critical discussions contained in justice-oriented theory, instead portraying the movement of goods as an “apolitical science of circulation”. In the U.S., for instance, politicizing urban freight overlooks a history of city industrial zoning practices, infrastructure construction, exclusionary decision-making, and consequent path dependency that placed key logistics facilities including highways, manufacturing plants, warehouses and distribution centers disproportionately near low-income households and non-white, populations of color. The longitudinal effects of these institutional decisions are still largely visible today.

Transportation research also inconsistently defines and measures equity. In a review of equity in transportation literature, Lewis et al. describe equity as an empty conceptual space that “authors then fill … either explicitly with clearly defined arguments or implicitly with whatever idea of justice intuitively comes to mind” (p. 2). Arbitrarily engaging with equity concepts, the authors argue, creates confusion that is both normative (e.g. what does an equitable urban freight system look like?) and positive (e.g. what measurable thresholds determine whether an urban freight outcome is inequitable?). Consequently, most equity research measure unequal distributions of burdens and/or benefits but spend less time identifying when and why unequal distributions are unjust.

Therefore, this paper synthesizes prevailing discourse around equity and, by extension, justice in transportation research and urban freight literature.

Authors: Travis FriedDr. Anne Goodchild, Ivan Sanchez Diaz (Chalmers University), Michael Browne (Gothenburg University)

Recommended Citation:
Travis Fried, Anne Goodchild, Michael Browne & Ivan Sanchez-Diaz (2023). Seeking Equity and Justice in Urban Freight: Where to Look? Transport Reviews, DOI: https://doi.org/10.1080/01441647.2023.2247165

Paper

An Empirical Analysis of Passenger Vehicle Dwell Time and Curb Management Strategies for Ride-Hailing Pick-Up/Drop-Off Operations

URL: https://doi.org/10.1007/s11116-023-10380-6

Publication: Transportation

Publication Date: 2023

Summary:

With the dramatic and recent growth in demand for curbside pick-up and drop-off by ride-hailing services, as well as online shopping and associated deliveries, balancing the needs of roadway users is increasingly critical. Local governments lack tools to evaluate the impacts of curb management strategies that prioritize different users’ needs. The dwell time of passenger vehicles picking up/dropping off (PUDO) passengers, including ride-hailing vehicles, taxis, and other cars, is a vital metric for curb management, but little is understood about the key factors that affect it. This research used a hazard-based duration modeling approach to describe the PUDO dwell times of over 6,000 passenger vehicles conducted in Seattle, Wash. Additionally, a before-after study approach was used to assess the effects of two curb management strategies: adding PUDO zones and geofencing. Results showed that the number of passenger maneuvers, location and time of day, and traffic and operation management factors significantly affected PUDO dwell times. PUDO operations took longer with more passengers, pick-ups (as opposed to drop-offs), vehicle´s trunk access, curbside stops, and in the afternoon. More vehicles at the curb and in adjacent travel lanes were found to be related to shorter PUDO dwell times but with a less practical significance. Ride-hailing vehicles tended to spend less time conducting PUDOs than other passenger vehicles and taxis. Adding PUDO zones, together with geofencing, was found to be related to faster PUDO operations at the curb. Suggestions are made for the future design of curb management strategies to accommodate ride-hailing operations.

Authors: José Luis Machado LeónDr. Anne Goodchild, Don MacKenzie (University of Washington College of Engineering)

Recommended Citation:
Machado-León, J.L., MacKenzie, D. & Goodchild, A. An Empirical Analysis of Passenger Vehicle Dwell Time and Curb Management Strategies for Ride-Hailing Pick-Up/Drop-Off Operations. Transportation (2023). https://doi.org/10.1007/s11116-023-10380-6

Paper

Estimating Truck Trips with Product Specific Data: A Disruption Case Study in Washington Potatoes

URL: https://doi.org/10.3328/TL.2012.04.03.153-166

Publication: Transportation Letters: The International Journal of Transportation Research

Volume: 4 (3)

Publication Date: 2013

Summary:

Currently, knowledge of actual freight flows in the US is insufficient at a level of geographic resolution that permits corridor-level freight transportation analysis and planning. Commodity specific origins, destinations, and routes are typically estimated from four-step models or commodity flow models. At a sub-regional level, both of these families of models are built on important assumptions driven by the limited availability of data. This study was motivated by a desire to determine whether efforts to gather corridor-level freight movement data will bring significant new insights over current approaches to freight transportation modeling. Through a case study of Washington State’s potato and value added potato products industry, we show that significant insight can be gained by collecting commodity-specific truck trip generation and destination data: the approach allows product specific truck trips to be estimated for each roadway link. When considering a network change, the number of affected trips can be identified, and their re-route distance quantified.

Authors: Dr. Anne Goodchild, Derik Andreoli, Eric Jessup

Recommended Citation:
Derik Andreoli, Anne Goodchild & Eric Jessup (2012) Estimating truck trips with product specific data: a disruption case study in Washington potatoes, Transportation Letters, 4:3, 153-166, https://doi.org/10.3328/TL.2012.04.03.153-166

Paper

SimMobility Freight: An Agent-Based Urban Freight Simulator for Evaluating Logistics Solutions

URL: https://doi.org/10.1016/j.tre.2020.102017

Publication: Transportation Research Part E: Logistics and Transportation Review

Volume: 141

Publication Date: 2020

Summary:

Despite significant advances in freight transport modeling in recent years, there is still lack of available tools for evaluating novel logistics solutions. We introduce the framework of SimMobility Freight, which is part of SimMobility, a multi-scale agent-based urban transportation simulation platform. SimMobility Freight is capable of simulating commodity contracts, logistics and vehicle operation planning and parking decisions in a fully-disaggregate manner. This allows us to evaluate alternative logistics solutions and measure their impacts. To illustrate its capability, we conduct an analysis of delivery time window regulations, assessing the policy impacts.

Authors: Dr. Giacomo Dalla Chiara, Takanori Sakai, André Romano Alho, B.K. Bhavathrathan, Raja Gopalakrish, Peiyu Jinge, Tetsuro Hyodo, Lynette Cheah, Moshe Ben-Akivae

Recommended Citation:
Sakai, T., Romano Alho, A., Bhavathrathan, B., Chiara, G. D., Gopalakrishnan, R., Jing, P., Hyodo, T., Cheah, L., & Ben-Akiva, M. (2020). SimMobility Freight: An Agent-Based Urban Freight Simulator for Evaluating Logistics Solutions. Transportation Research Part E: Logistics and Transportation Review, 141, 102017. https://doi.org/10.1016/j.tre.2020.102017

Paper

GPS Tracking of Freight Vehicles to Identify and Classify Bottlenecks

URL: https://ieeexplore.ieee.org/abstract/document/6338666

Publication: Intelligent Transportation Systems (ITSC), 2012 15th International IEEE Conference

Publication Date: 2012

Summary:

This paper presents a systematic methodology for identifying and ranking bottlenecks using probe data collected by commercial GPS fleet management devices. This methodology is based on the hypotheses that truck speed distributions can be represented by either a unimodal or bimodal probability density function, and it proposes a new reliability measure for evaluating roadway performance.

Authors: Dr. Ed McCormack, Wenjuan Zhao, Daniel J. Dailey

Recommended Citation:
McCormack, E., Zhao, W., & Dailey, D. J. (2012, September). GPS Tracking of Freight Vehicles to Identify and Classify Bottlenecks. In 2012 15th International IEEE Conference on Intelligent Transportation Systems (pp. 1245-1249). IEEE.

Paper

Measuring Delivery Route Cost Trade-Offs Between Electric-Assist Cargo Bicycles and Delivery Trucks in Dense Urban Areas

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URL: https://doi.org/10.1186/s12544-019-0349-5

Publication: European Transport Research Review

Volume: 11

Publication Date: 2019

Summary:

Introduction

Completing urban freight deliveries is increasingly a challenge in congested urban areas, particularly when delivery trucks are required to meet time windows. Depending on the route characteristics, Electric Assist (EA) cargo bicycles may serve as an economically viable alternative to delivery trucks. The purpose of this paper is to compare the delivery route cost trade-offs between box delivery trucks and EA cargo bicycles that have the same route and delivery characteristics, and to explore the question, under what conditions do EA cargo bikes perform at a lower cost than typical delivery trucks?

Methods

The independent variables, constant variables, and assumptions used for the cost function comparison model were gathered through data collection and a literature review. A delivery route in Seattle was observed and used as the base case; the same route was then modeled using EA cargo bicycles.

Four separate delivery scenarios were modeled to evaluate how the following independent route characteristics would impact delivery route cost – distance between a distribution center (DC) and a neighborhood, number of stops, distance between each stop, and number of parcels per stop.

Results

The analysis shows that three of the four modeled route characteristics affect the cost trade-offs between delivery trucks and EA cargo bikes. EA cargo bikes are more cost effective than delivery trucks for deliveries in close proximity to the DC (less than 2 miles for the observed delivery route with 50 parcels per stop and less than 6 miles for the hypothetical delivery route with 10 parcels per stop) and at which there is a high density of residential units and low delivery volumes per stop.

Conclusion

Delivery trucks are more cost effective for greater distances from the DC and for large volume deliveries to one stop.

Authors: Polina ButrinaDr. Anne GoodchildManali ShethDr. Ed McCormack

Recommended Citation:
Sheth, Manali, Polina Butrina, Anne Goodchild, and Edward McCormack. "Measuring delivery route cost trade-offs between electric-assist cargo bicycles and delivery trucks in dense urban areas." European Transport Research Review 11, no. 1 (2019): 11.

Paper

A Description of Fatal Bicycle Truck Accidents in the United States: 2000 to 2010

URL: https://trid.trb.org/view/1394216

Publication: Transportation Research Board 95th Annual Meeting

Volume: 16-5911

Publication Date: 2016

Summary:

Bicycling is being encouraged across the US and the world as a low-impact, environmentally friendly mode of transportation. In the US, many states and cities, especially cities facing congestion issues, are encouraging cycling as an alternative to automobiles. However, as cities grow and consumption increases, freight traffic in cities will increase as well, leading to higher amounts of interactions between cyclists and trucks. This paper will describe where and how accidents between cyclists and trucks occur. From 2000 to 2010, 807 bicyclists were killed the United States in accidents involving trucks. In 2009, trucks accounted for 9.5% of fatal bicycle accidents, despite trucks only accounting for 4.5% of registered vehicles. The typical fatal bike-truck accident happens in an urban area on an arterial street with a speed limit of 35 or 45 mph. It is about equally likely to occur mid-block or at an intersection. Most accidents involved trucks going straight (56%), and right-turning trucks were involved in a much larger number of accidents (24%) than left turning trucks (7%). Methods such as providing bicycle lanes, or even physically separated bicycle tracks, will not be sufficient to address bicycle-truck collisions, as a significant number of accidents (49%) occur in intersections or are intersection related. Cities with a higher mode-share of bicycling had a lower rate of bicycle-truck fatality accidents.

Authors: Dr. Anne Goodchild, Jerome Drescher

Recommended Citation:
Drescher, Jerome and Anne Goodchild. (2016), "A Description of Fatal Bicycle Truck Accidents in the United States: 2000 to 2010," Accepted for presentation at the 95th Transportation Research Board Annual Meeting, Washington DC, January 10-14. [Paper # 16-5911]

Paper

Examining the Differential Responses of Shippers and Motor Carriers to Travel Time Variability

URL: http://dx.doi.org/10.4018/jal.2012010103

Publication: International Journal of Applied Logistics

Volume: 3 (1)

Pages: 39-53

Publication Date: 2012

Summary:

Shippers and motor carriers are impacted by and react differently to travel time variability due to their positions within the supply chain and end goals. Through interviews and focus groups these differences have been further examined. Shippers, defined here as entities that send or receive goods, but do not provide the transportation themselves, are most often concerned with longer-term disruptions, which are typically considered within the context of transportation system resilience. Motor carriers, defined here as entities engaged in transporting goods for shippers, are most often concerned with daily travel time variability from events such as congestion. This paper describes the disparity in concerns and the strategies shippers and motor carriers are likely to engage in to address time travel variability. This knowledge allows for a better understanding of how investments to mitigate travel time variability will impact shippers and motor carriers.

Authors: Dr. Anne GoodchildDr. Ed McCormack, Kelly Pitera

Recommended Citation:
Goodchild, Anne V., Kelly Pitera, and Edward McCormack. "Examining the differential responses of shippers and motor carriers to travel time variability." International Journal of Applied Logistics (IJAL) 3, no. 1 (2012): 39-53.

Paper

Understanding Freight Trip Chaining Behavior Using Spatial Data Mining Approach with GPS Data

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URL: http://dx.doi.org/10.3141/2596-06

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

Volume: 2596

Pages: 44-54

Publication Date: 2016

Summary:

Freight systems are a critical yet complex component of the transportation domain. Understanding the dynamic of freight movements will help in better management of freight demand and eventually improve freight system efficiency. This paper presents a series of data-mining algorithms to extract an individual truck’s trip-chaining information from multi-day GPS data. Individual trucks’ anchor points were identified with the spatial clustering algorithm for density-based spatial clustering of applications with noise. The anchor points were linked to construct individual trucks’ trip chains with 3-day GPS data, which showed that 51% of the trucks in the data set had at least one trip chain. A partitioning around medoids nonhierarchical clustering algorithm was applied to group trucks with similar trip-chaining characteristics. Four clusters were generated and validated by visual inspection when the trip-chaining statistics were distinct from each other. This study sheds light on modeling freight-chaining behavior in the context of massive freight GPS data sets. The proposed trip chain extraction and behavior classification algorithms can be readily implemented by transportation researchers and practitioners to facilitate the development of activity-based freight demand models.

Authors: Dr. Ed McCormack, X. Ma, W. Yong, and Yinhai Wang

Recommended Citation:
Ma, Xiaolei & Wang, Yong & McCormack, Edward & Wang, Yinhai. (2016). Understanding Freight Trip-Chaining Behavior Using a Spatial Data-Mining Approach with GPS Data. Transportation Research Record: Journal of the Transportation Research Board. 2596. 44-54. 10.3141/2596-06.