Skip to content
Technical Report

Cost, Emissions, and Customer Service Trade-Off Analysis In Pickup and Delivery Systems

Publication: Oregon Department of Transportation, Research Section
Publication Date: 2011
Summary:

This research offers a novel formulation for including emissions into fleet assignment and vehicle routing and for the trade-offs faced by fleet operators between cost, emissions, and service quality. This approach enables evaluation of the impact of a variety of internal changes (e.g. time window schemes) and external policies (e.g. spatial restrictions), and enables comparisons of the relative impacts on fleet emissions. To apply the above approach to real fleets, three different case studies were developed. Each of these cases has significant differences in their fleet composition, customers’ requirements, and operational features that provide this research with the opportunity to explore different scenarios.

The research includes estimations of the impact on cost and CO2 and NOX emissions from fleet upgrades, the impact on cost, emissions, and customer wait time when demand density or location changes, and the impact on cost, emissions, and customer wait time from congestion and time window flexibility. Additionally, it shows that any infrastructure use restriction increases cost and emissions. A discussion of the implications for policymakers and fleet operators in a variety of physical and transportation environments is also presented.

Authors: Dr. Anne Goodchild, Felipe Sandoval
Recommended Citation:
Goodchild, A., & Sandoval, F. (2011). Cost, Emissions, and Customer Service Trade-Off Analysis In Pickup and Delivery Systems (No. OR-RD 11-13). Oregon Department of Transportation Research Section.
Paper

An Analytical Model for Vehicle Miles Traveled and Carbon Emissions for Goods Delivery Scenarios

 
Download PDF  (0.84 MB)
Publication: European Transport Research Review
Volume: 10
Publication Date: 2018
Summary:

This paper presents an analytical model to contrast the carbon emissions from a number of goods delivery methods. This includes individuals travelling to the store by car, and delivery trucks delivering to homes. While the impact of growing home delivery services has been studied with combinatorial approaches, those approaches do not allow for systematic conclusions regarding when the service provides net benefit. The use of the analytical approach presented here, allows for more systematic relationships to be established between problem parameters, and therefore broader conclusions regarding when delivery services may provide a CO2 benefit over personal travel.

Methods

Analytical mathematical models are developed to approximate total vehicle miles traveled (VMT) and carbon emissions for a personal vehicle travel scenario, a local depot vehicle travel scenario, and a regional warehouse travel scenario. A graphical heuristic is developed to compare the carbon emissions of a personal vehicle travel scenario and local depot delivery scenario.

Results

The analytical approach developed and presented in the paper demonstrates that two key variables drive whether a delivery service or personal travel will provide a lower CO2 solution. These are the emissions ratio, and customer density. The emissions ratio represents the relative emissions impact of the delivery vehicle when compared to the personal vehicle. The results show that with a small number of customers, and low emissions ratio, personal travel is preferred. In contrast, with a high number of customers and low emissions ratio, delivery service is preferred.

Conclusions

While other research into the impact of delivery services on CO2 emissions has generally used a combinatorial approach, this paper considers the problem using an analytical model. A detailed simulation can provide locational specificity, but provides less insight into the fundamental drivers of system behavior. The analytical approach exposes the problem’s basic relationships that are independent of local geography and infrastructure. The result is a simple method for identifying context when personal travel, or delivery service, is more CO2 efficient.

Authors: Dr. Anne Goodchild, Erica Wygonik, Nathan Mayes
Recommended Citation:
Goodchild, Anne, Erica Wygonik, and Nathan Mayes. "An analytical model for vehicle miles traveled and carbon emissions for goods delivery scenarios." European Transport Research Review 10, no. 1 (2018): 8.
Paper

Urban Form and Last-Mile Goods Movement: Factors Affecting Vehicle Miles Travelled and Emissions

 
Download PDF  (0.04 MB)
Publication: Transportation Research Part D: Transport and Environment
Volume: 61 (A)
Pages: 217-229
Publication Date: 2018
Summary:

There are established relationships between urban form and passenger travel, but less is known about urban form and goods movement. The work presented in this paper evaluates how the design of a delivery service and the urban form in which it operates affects its performance, as measured by vehicle miles traveled, CO2, NOx, and PM10 emissions.

This work compares simulated amounts of VMT, CO2, NOx, and PM10 generated by last-mile travel in several different development patterns and in many different goods movement structures, including various warehouse locations. Last-mile travel includes personal travel or delivery vehicles delivering goods to customers. Regression models for each goods movement scheme and models that compare sets of goods movement schemes were developed. The most influential variables in all models were measures of roadway density and proximity of a service area to the regional warehouse.

These efforts will support urban planning for goods movement, inform policies designed to mitigate the impacts of goods movement vehicles, and provide insights into achieving sustainability targets, especially as online shopping and goods delivery become more prevalent.

Authors: Dr. Anne Goodchild, Erica Wygonik
Recommended Citation:
Wygonik, Erica and Anne Goodchild. (2018) Urban Form and Last-Mile Goods Movement: Factors Affecting Vehicle Miles Travelled and Emissions. Transportation Research. Part D, Transport and Environment, 61, 217–229. https://doi.org/10.1016/j.trd.2016.09.015
Paper

Delivery by Drone: An Evaluation of Unmanned Aerial Vehicle Technology in Reducing CO2 Emissions in the Delivery Service Industry

 
Download PDF  (2.33 MB)
Publication: Transportation Research Part D: Transport and Environment
Volume: 61
Pages: 58-67
Publication Date: 2018
Summary:

This research paper estimates carbon dioxide (CO2) emissions and vehicle-miles traveled (VMT) levels of two delivery models, one by trucks and the other by unmanned aerial vehicles (UAVs), or “drones.”

Using several ArcGIS tools and emission standards within a framework of logistical and operational assumptions, it has been found that emission results vary greatly and are highly dependent on the energy requirements of the drone, as well as the distance it must travel and the number of recipients it serves.

Still, general conditions are identified under which drones are likely to provide a CO2 benefit – when service zones are close to the depot, have small numbers of stops, or both. Additionally, measures of VMT for both modes were found to be relatively consistent with existing literature that compares traditional passenger travel with truck delivery.

Authors: Dr. Anne Goodchild, Jordan Toy
Recommended Citation:
Goodchild, Anne, and Jordan Toy. "Delivery by Drone: An Evaluation of Unmanned Aerial Vehicle Technology in Reducing CO2 Emissions in the Delivery Service Industry" Transportation Research Part D: Transport and Environment 61 (2018): 58-67.
Presentation

Using a GIS-based Emissions Minimization Vehicle Routing Problem with Time Windows (EVRPTW) Model to Evaluate CO2 Emissions and Costs: Two Case Studies Comparing Changes Within and Between Fleets

Publication: Transportation Research Board 90th Annual Meeting
Publication Date: 2010
Summary:

Growing pressure to limit greenhouse gas emissions is changing the way businesses operate. A model was developed in ArcGIS to evaluate the trade-offs between cost, service quality (represented by time window guarantees), and emissions of urban pickup and delivery systems under these changing pressures.

A specific case study involving a real fleet with specific operational characteristics is modeled as an emissions minimization vehicle routing problem with time windows (EVRPTW). Analyses of different external policies and internal operational changes provide insight into the impact of these changes on cost, service quality, and emissions. Specific considerations of the influence of time windows, customer density, and vehicle choice are included.

The results show a stable relationship between monetary cost and kilograms of CO2, with each kilogram of CO2 associated with a $3.50 increase in cost, illustrating the influence of fuel use on both cost and emissions. In addition, customer density and time window length are strongly correlated with monetary cost and kilograms of CO2 per order. The addition of 80 customers or extending the time window 100 minutes would save approximately $3.50 and 1 kilogram of CO2 per order. Lastly, the evaluation of four different fleets illustrates significant environmental and monetary gains can be achieved through the use of hybrid vehicles.

Authors: Erica Wygonik
Recommended Citation:
Wygonik, Erica and Anne V. Goodchild. “Using a GIS-based emissions minimization vehicle routing problem with time windows (EVRPTW) model to evaluate emissions and cost trade-offs in a case study of an urban delivery system.” Proc., 90th Annual Meeting of the Transportation Research Board, Transportation Research Board, Washington, DC.
Student Thesis and Dissertations

Emissions, Cost, and Customer Service Trade-off Analyses in Pickup and Delivery Systems

Publication Date: 2011
Summary:

As commercial vehicle activity grows, the environmental impacts of these movements have increasing negative effects, particularly in urban areas. The transportation sector is the largest producer of CO2 emissions in the United States, by end-use sector, accounting for 32% of CO2 emissions from fossil fuel combustion in 2008. Medium and heavy-duty trucks account for close to 22% of CO2 emissions within the transportation sector, making systems using these vehicles key contributors to air quality problems. An important well-known type of such systems is the “pickup and delivery” in which a fleet of vehicles pickups and/or delivers goods from customers.

Companies operating fleet of vehicles reduce their cost by efficiently designing the routes their vehicles follow and the schedules at which customers will be visited. This principle especially applies to pickup and delivery systems. Customers are spread out in urban regions or are located in different states which makes it critical to efficiently design the routes and schedules vehicles will follow. So far, a less costly operation has been the main focus of these companies, particularly pickup and delivery systems, and less attention has been paid to understand how cost and emissions relate and how to directly reduce the environmental impacts of their transportation activities. This is the research opportunity that motivates the present study.

While emissions from transportation activities are mostly understood broadly, this research looks carefully at relationships between cost, emissions and service quality at an individual-fleet level. This approach enables evaluation of the impact of a variety of internal changes and external policies based on different time window schemes, exposure to congestion, or impact of CO2 taxation. It this makes it possible to obtain particular and valuable insights from the changes in the relationship between cost, emissions and service quality for different fleet characteristics.

In an effort to apply the above approach to real fleets, two different case studies are approached and presented in this thesis. Each of these cases has significant differences in their fleet composition, customers’ requirements and operational features that provide this research with the opportunity to explore different scenarios.

Three research questions guide this research. They are explained in more detailed below. The present study does not seek to provide a conclusive answer for each of the research questions but does shed light on general insights and relationships for each of the different features presented in the road network, fleet composition, and customer features.

In summary, this research provides a better understanding of the relationships between fleet operating costs, emissions reductions and impacts on customer service. The insights are useful for companies trying to develop effective emission-reduction strategies. Additionally, public agencies can use these results to develop emissions reductions policies.

Authors: Felipe Sandoval
Recommended Citation:
Sandoval, Felipe (2011). Emissions, Cost, and Customer Service Trade-off Analyses in Pickup and Delivery Systems, University of Washington Master's Degree Thesis.
Thesis: Array
Student Thesis and Dissertations

Moving Goods to Consumers: Land Use Patterns, Logistics, and Emissions

Publication Date: 2014
Summary:

Worldwide, awareness has been raised about the dangers of growing greenhouse gas emissions. In the United States, transportation is a key contributor to greenhouse gas emissions. American and European researchers have identified a potential to reduce greenhouse gas emissions by replacing passenger vehicle travel with delivery service. These reductions are possible because, while delivery vehicles have higher rates of greenhouse gas emissions than private light-duty vehicles, the routing of delivery vehicles to customers is far more efficient than those customers traveling independently. In addition to lowering travel-associated greenhouse gas emissions, because of their more efficient routing and tendency to occur during off-peak hours, delivery services have the potential to reduce congestion. Thus, replacing passenger vehicle travel with delivery service provides opportunity to address global concerns – greenhouse gas emissions and congestion. While addressing the impact of transportation on greenhouse gas emissions is critical, transportation also produces significant levels of criteria pollutants, which impact the health of those in the immediate area. These impacts are of particular concern in urban areas, which due to their constrained land availability increase proximity of residents to the roadway network. In the United States, heavy vehicles (those typically used for deliveries) produce a disproportionate amount of NOx and particulate matter – heavy vehicles represent roughly 9% of vehicle miles travelled but produce nearly 50% of the NOx and PM10 from transportation. Researchers have noted that urban policies designed to address local concerns including air quality impacts and noise pollution – like time and size restrictions – have a tendency to increase global impacts, by increasing the number of vehicles on the road, by increasing the total VMT required, or by increasing the amount of CO2 generated. The work presented here is designed to determine whether replacing passenger vehicle travel with delivery service can address both concerns simultaneously. In other words, can replacing passenger travel with delivery service reduce congestion and CO2 emissions as well as selected criteria pollutants? Further, does the design of the delivery service impacts the results? Lastly, how do these impacts differ in rural versus urban land use patterns? This work models the amount of VMT, CO2, NOx, and PM10 generated by personal travel and delivery vehicles in a number of different development patterns and in a number of different scenarios, including various warehouse locations. In all scenarios, VMT is reduced through the use of delivery service, and in all scenarios, NOx and PM10 are lowest when passenger vehicles are used for the last mile of travel. The goods movement scheme that results in the lowest generation of CO2, however, varies by municipality. Regression models for each goods movement scheme and models that compare sets of goods movement schemes were developed. The most influential variables in all models were measures of roadway density and proximity of a service area to the regional warehouse. These results allow for a comparison of the impacts of greenhouse gas emissions in the form of CO2 to local criteria pollutants (NOx and PM10) for each scenario. These efforts will contribute to increased integration of goods movement in urban planning, inform policies designed to mitigate the impacts of goods movement vehicles, and provide insights into achieving sustainability targets, especially as online shopping and goods delivery becomes more prevalent.

Authors: Erica Wygonik
Recommended Citation:
Wygonic, Erica. 2014, Moving Goods to Consumers: Land Use Patterns, Logistics, and Emissions, University of Washington, Doctoral Dissertation.
Thesis: Array
Technical Report

Changing Retail Business Models and the Impact on CO2 Emissions from Transport: E-commerce Deliveries in Urban and Rural Areas

 
Download PDF  (2.21 MB)
Publication: Pacific Northwest Transportation Consortium (PacTrans)
Volume: 2013-S-UW-0023
Publication Date: 2014
Summary:

While researchers have found relationships between passenger vehicle travel and smart growth development patterns, similar relationships have not been extensively studied between urban form and goods movement trip-making patterns. In rural areas, where shopping choice is more limited, goods movement delivery has the potential to be relatively more important than in more urban areas. As such, this work examines the relationships between certain development pattern characteristics including density and distance from warehousing. This work models the amount of carbon dioxide (CO2), nitrogen oxides (NOx), and Particle Matter (PM10) generated by personal travel and delivery vehicles in several different scenarios, including various warehouse locations. Linear models were estimated via regression modeling for each dependent variable for each goods movement strategy. Parsimonious models maintained nearly all of the explanatory power of more complex models and relied on one or two variables – a measure of road density and a measure of distance to the warehouse. Increasing road density or decreasing the distance to the warehouse reduces the impacts as measured in the dependent variables (vehicle miles traveled (VMT), CO2, NOx, and PM10). The authors find that delivery services offer relatively more CO2 reduction benefit in rural areas when compared to CO2 urban areas, and that in all cases delivery services offer significant VMT reductions. Delivery services in both urban and rural areas, however, increase NOX and PM10 emissions.

Authors: Dr. Anne Goodchild, Erica Wygonik
Recommended Citation:
Goodchild, Anne, and Erica Wygonik. Changing retail business models and the impact on CO2 emissions from transport: e-commerce deliveries in urban and rural areas. No. 2013-S-UW-0023. Pacific Northwest Transportation Consortium, 2014.
Paper

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

 
Download PDF  (0.31 MB)
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. 

Biking for Goods: A Case Study on the Seattle Pedaling Relief Project

1. Introduction
One of the disruptions brought by the COVID-19 pandemic was the reduction of in-store shopping, and the consequent increase in online shopping and home deliveries. However, not everyone had equal access to online shopping and home-delivery services. Customers relying on food banks were forced to shop in-store even during the pandemic. In 2020, the Cascade Bicycle Club started the Pedaling Relief Project (PRP) – a not-for-profit home delivery service run by volunteers using bikes to pick up food at food banks and deliver to food bank customers, among other services.

The Urban Freight Lab collaborates with the Cascade Bicycle Club (CBC) to study and improve PRP operations. For this work, students in Prof. Anne Goodchild’s Transportation Engineering course on Transportation Logistics (CET 587) are undertaking a case study: to analyze the transport and logistics system of the Pedaling Relief Project and provide recommendations for how to improve operations.

2. Background
2.1. Food rescue at a glance
An estimated 94,500 tons of food from Seattle business establishments end up in compost and landfills each year, while many members of our community remain food insecure. The process of food rescuing consists of the gleaning of edible food from business establishments – called donor businesses such as grocery stores, restaurants, and commissary kitchens – that otherwise would enter the waste stream and be re-distributed to local food programs. Hunger relief agencies, also referred to as food banks, are non-profit organizations that collect rescued food, either directly from businesses or through food rescue distributors (such as Food Lifeline or Northeast Harvest) and re-distribute it to the community through meal programs, walk-ins, and pop-up food pantries, student backpack programs, among others.

Read more about the Seattle food rescue system in SCTL’s report (2020) on “Improving Food Rescue in Seattle: What Can Be Learned from a Supply Chain View?

2.2. Pedaling Relief Project
In 2020 the Cascade Bicycle Club started the Pedaling Relief Project (PRP), a volunteer-based program that collaborates with local food banks to offer three main types of services — (1) grocery delivery, (2) food rescue, (3) little free pantry restocking — coordinating a network of volunteers on bikes.

  1. Grocery delivery (GD) service consists of picking up grocery bags from food banks and performing delivery routes, distributing food to food bank customers that asked for home delivery services.
  2. Food rescue (FR) services support the existing distributors by picking up food at business establishments and carrying rescued food to local food banks.
  3. Little free pantries restocking (LFPR) services consist of picking up food at local food banks and carrying it to neighborhood micro pantries –containers placed on local streets and open to everyone to store food from donors to whoever needs it. Learn more about the Little free pantries project on thelittlefreepantries.org.

Volunteers use their own bikes, with some cargo carry capacity, or can request a bike trailer or cargo bike from the Cascade Bicycle Club.

2.3. Cargo Bikes
Cargo bikes are two/three/four-wheel bikes with some cargo-carrying capacity. They are increasingly used as an alternative mode to trucks and vans to transport goods in urban areas. Cargo bikes are often supported by an electric motor that assists the driver when pedaling. Compared to internal combustion engine vehicles, cargo bikes do not produce tailpipe emissions and they consume less energy than electric vans (Verlinghieri et al., 2021). They also offer several operational advantages: they are more agile in navigating urban road traffic, they can use alternative road infrastructure such as bike lanes and sidewalks to drive and park, they can park closer to their delivery destination, reducing walking distances and parking dwell times (Dalla Chiara et al., 2020).

3. Project instructions

The CBC provided access to anonymous data on the PRP operations for the exclusive use of the 2022 CET 587 course student cohort final projects. Students are asked to individually perform empirical research using the provided data and/or self-collected data on the PRP operations with the following objectives:

  • Empirically analyze and describe PRP operations.
  • Provide recommendations on what actions can be taken to improve PRP operations.

Projects will meet the following two requirements:

  • Use the provided data and/or self-collected and/or publicly sourced data to perform empirical analysis
  • Provide justified and concrete recommendations on how to improve the PRP.
  • Complete deliverables 1 and 2 (see below), which consist of 2 presentations, a project proposal, and a final project report.

Project progress timeline and deliverables:

Weeks Progress & Deliverables
1-2 Become familiar with R language programming; PRP background and data
3 CBC gives a guest lecture about PRP
4-5 Project proposal; 2-minute lightning talk about the project proposal
Deliverable 1: 1-page project proposal
6-10 Implement proposed methodology and perform research
11 Each student will give a 15-minute presentation of the main results of the project
Deliverable 2: Final report
The following are potential project directions:
  • Analyze current routes performed by volunteers. How can they be improved? Get the work done more quickly, or with fewer bikes?
  • Analyze data from little free pantries restocking. Collect additional data on the use of Little Free Pantries by manual observations or by installing sensors in a few of them. Can we model demand and supply for food donations?
  • Collect and analyze GPS data by signing up and performing some of the PRP routes yourself. What type of infrastructure do cargo bikes need and how does street and curb use behavior differ between cargo bikes and vans? What can the city do to better support this type of activity?
  • Analyze volunteers’ behaviors data. Is it possible to model the supply of volunteers? Can you simulate different scenarios of volunteer supply?
  • Develop your own direction with approval.

Students will be provided with a base dataset on PRP operations. Students are encouraged to use other datasets self-collected or from public data sources (e.g. check out the SDOT Open Data Portal), to share ideas in class and among each other, to use as much as possible class time, guest lectures and office hours to ask questions and share ideas.

1: 1-page project proposal and 2-minute lightning talk describing motivation, project objective(s) and research question(s), proposed methodology (data to use/collect, methods to implement), and expected results.

2: Final report and 10-minute presentation describing data used, including sample size and sample statistics, how data collection was performed, empirical analysis performed using data and results from the analysis, and conclusions, key findings, and key recommendations.