## 2 Method
### Goal and Scope Definition
#### 2.2.2 System Boundary  
The definition of the system boundaries plays an important role in the LCA of roads [43].  
In the present study, the system boundaries were defined on the basis of the work of [PERSON] et al. [45], who summarised all the phases that should be included when performing an LCA of a road. In this study, this scheme has been adapted to an e-road.  
[PERSON] et al. divided the system boundaries into three phases: construction, maintenance and operation. According to their definition, the final disposal of a road is normally included in the maintenance of the road, and some of the materials are reused. However, most roads have no final end. Instead, they are generally reconstructed or replaced by a new road while the old road remains in operation [45].  
In this study, the construction phase of the e-road includes the removal of the wear and binder layers of the existing road and the application of WPT equipment as well as the following deposition and compaction of asphalt. The following are included in the construction phase:  
* Production of the raw materials;
* Transport of the raw materials to the construction site;
* Transport of the on-site equipment to the construction site;
* Equipment use (fuels);
* Construction of the e-road;
* Production of the charging (and any other electrical devices);
* Transport of the charging unit to the road construction site;
* Installation of the charging devices.  
The construction method is described in Section 3. The construction of the e-road involves the refurbishment of a traditional road, and the construction operations only involve asphalt layers, and the base and sub-base layers remain unchanged. Thus, the base and sub-base layers have been excluded from the analysis.  
E-roads also present particular features during the maintenance phase. The alignment of the vehicle with the coils embedded in the road is a fundamental aspect when it comes to charging efficiency. In fact, for recharging reasons, the maximum allowed misalignment for power transfer is approximately 20 cm [46]. The presence of a discontinuity in the asphalt layer and the fixed trajectory the vehicle has to follow in order to maximise charging can lead to a need for additional maintenance, compared to a traditional road.  
In order to understand the effects of WPT technologies on the maintenance of pavements, [PERSON] et al. [47] performed a finite element simulation. Moreover, the maintenance operations, due to the replacement of WPT components, were included in the analysis.  
As far as the maintenance phase is concerned, the following activities have been included in the present analysis:  
* Production of the raw materials required for the maintenance;
* Transport of the raw materials to the road site;
* Transport of the on-site equipment;
* Equipment use (fuels);
* Maintenance of the charging unit and WPT components.  
The winter maintenance procedures, such as sand and salt printing and snow clearance, depend on the weather conditions and have been excluded from the analysis, since their relevance is negligible [9].  
The impacts attributable to the end-of-life phase of the pavement depend on the ultimate fates of the road surface and its constituent materials, which are notoriously difficult to determine a priori. At the end of its service life, a pavement can meet one of three fates: It may (1) be demolished and landfilled; (2) be demolished and recycled; or (3) remain in situ and serve as a support for a subsequent pavement structure [43]. As infrastructures are rarely demolished completely or disposed of after the end of their life [48], this phase has not been considered in this analysis.