How will we know if the GreenTurn solutions worked?

An interview with Julia Amaral

Julia is a postdoctoral researcher at the Department of Transport and Regional Economics, Antwerp University. In GreenTurn, Julia and her team developed a framework to better understand the challenges of e-commerce, considering the different needs of businesses, delivery providers and customers. This framework will help measure how different pilot projects perform in terms of costs, social benefits and environmental impact.

1. How do we know if a delivery is truly sustainable? What should we be measuring?

Sustainability is relative. Every delivery requires resources and generates some form of impact, so the question is not necessarily whether a delivery is sustainable, but whether we can make it more sustainable compared to the alternatives.

There are different ways to achieve this. We often think immediately of replacing fossil fuel vehicles with electric vehicles, which eliminates tailpipe emissions. But cleaner vehicles are only part of the solution. We can also improve the efficiency of logistics operations, for example, by consolidating deliveries and optimizing routes. And we can also focus on the demand side, encouraging consumers to make more sustainable choices.

This is why, in GreenTurn, we developed a framework that considers multiple dimensions of sustainability. Beyond environmental indicators, we also look at economic performance and social impacts. A solution that reduces emissions but significantly increases operational costs or negatively affects working conditions might not be sustainable in the broader sense. We need to consider these different dimensions together to understand the actual benefits and potential trade-offs.

2. When we talk about greener deliveries, we usually focus on CO₂ emissions. What important impacts are we overlooking?

CO₂ emissions from delivery vehicles are important because of their contribution to climate change, but they are far from the only impact we should consider. Other air pollutants, such as particulate matter and nitrogen oxides, affect local air quality and public health. However, looking at different types of emissions is only part of the challenge. We also need to consider impacts beyond the delivery vehicles themselves.

Take parcel lockers or collection points, for instance. Consolidating deliveries at these locations can reduce emissions from delivery vehicles, but if consumers drive their cars to collect parcels, some of those benefits may be offset. Packaging is another example. In GreenTurn, we are exploring reusable packaging solutions to reduce waste and promote more circular practices. These examples illustrate why evaluating the sustainability of e-commerce deliveries requires looking at the entire process, rather than focusing exclusively on emissions of the delivery vehicles.

3. What would you most like to know about the impact of e-commerce deliveries, but cannot yet measure reliably because the data is missing or difficult to obtain?

I think some of the biggest knowledge gaps concern the human side of logistics, particularly how people’s choices shape delivery operations and how these operations, in turn, affect people.

We can often obtain operational data, such as distances traveled, vehicle types, or the number of deliveries per tour. However, understanding the role of human behavior is more challenging. Consumer choices directly shape delivery demand and how logistics operations are organized. For example, preferences for next-day delivery, willingness to accept longer delivery windows, or purchasing and return habits all affect the efficiency of logistics operations. Of course, these choices are also shaped by the options and incentives offered by retailers and logistics providers. Understanding these interactions is essential to identify opportunities to encourage more sustainable delivery practices.

On the other side, we also need to better understand how logistics operations affect workers. Improving delivery efficiency might mean that a driver completes more deliveries during a shift, but what does that mean for their workload and stress levels? Operational indicators alone cannot answer that question.

These are particularly relevant challenges for GreenTurn, where we are exploring how consumer behavior can contribute to more sustainable e-commerce logistics. Understanding these human dimensions is essential to designing solutions that are both operationally efficient and socially sustainable.

4. Looking ahead, how can future EU-funded projects improve the way they measure and evaluate their real-world impact?

I don’t think the main challenge is necessarily developing more indicators. What we need is greater consistency in how indicators are defined, measured, and interpreted, so that results from different projects can be meaningfully compared.

Take vehicle emissions as an example. An electric vehicle produces no tailpipe emissions, but that does not mean its overall environmental footprint is zero. If we consider electricity generation, vehicle manufacturing, and battery production, the picture becomes more complex. Two projects might report the same indicator while including very different sources of emissions in their calculations.

Having clearer guidelines on measurement methods and system boundaries would help address this issue. At the same time, we need to be realistic about data availability. More comprehensive assessments are desirable, but they also require more information, which is not always accessible. There is a delicate balance between methodological rigor and practical feasibility: if we make the requirements too demanding, we risk not being able to evaluate impacts at all.

Ultimately, I believe the most important principle is to adopt a systemic perspective. Urban logistics systems are complex, with many actors and interactions, and improvements in one area can create unintended consequences elsewhere. If we focus too narrowly on a single indicator, we risk overlooking important trade-offs or simply shifting impacts from one part of the system to another. Meaningful sustainability assessments need to consider the bigger picture.