User

Two factors are important when calculating the construction footprint:

• Whether or not the same vehicle is used for all the kilometres travelled (if not: you are assigned an "average" vehicle)
• Whether or not you own the same vehicle, if it is always the same

We chose to allocate the construction footprint in proportion to the number of kilometres driven. But this approach had two drawbacks:

• It was extremely advantageous for short-distance drivers, whereas a vehicle that is driven less may wear out more quickly (an engine needs to run regularly) and therefore have a shorter lifespan.
• It did not make it possible to value the commitment of not owning one's own vehicle, and instead to practise car-sharing or occasional rental (because the construction footprint was the same, whether or not one owned one's own vehicle).

To overcome these two problems, and to better represent the fact that a vehicle that is owned but underused wears out faster and deserves a larger construction footprint, we apply a threshold for the construction part of the footprint, for owners.