Why is transportation typically not classified as a lifecycle stage?

Transportation is considered a critical component within the lifecycle assessment framework but is not classified as a distinct lifecycle stage primarily because it serves as a supportive function that connects different lifecycle phases. Instead of being a standalone stage, transportation is interspersed throughout all stages, from raw material extraction to manufacturing, distribution, and ultimately to the end-of-life disposal.

This connectivity means that transportation does not represent an isolated set of processes or impacts but rather acts as a facilitator that links one lifecycle phase to another. For instance, materials need to be transported from suppliers to manufacturers, products from manufacturers to retail channels, and eventually to consumers. Since transportation is ubiquitous and inherent to the functioning of various lifecycle stages, it is recognized as a continuous process rather than an independent stage.

In terms of lifecycle assessments, this understanding allows for a more integrated analysis of how transportation contributes to overall sustainability rather than treating it as a separate entity with distinct impacts. Thus, the choice that identifies transportation's role of occurring between all lifecycle stages accurately captures its significance in lifecycle assessments.