The aim of this document is to present the approach that has been used in CoEXist, that in a structured and sound way can be used by road authorities to assess the traffic impact of automation on a given road design, traffic controllers, regulations, etc. The traffic performance and space efficiency assessment approach utilizes outputs from automation-ready transport modelling tools as input. The traffic models are applied to a set of consistent experiments with respect to penetration rates and different mixes of AV classes, as described in deliverable D3.1. Relevant performance metrics, presented in deliverable D3.2, are calculated from the model outputs and used to assess the traffic impact of automation in terms of traffic performance for different infrastructure designs. An essential functionality of the assessment approach is to consider and visualize effects of the large uncertainties with respect to how different types of AVs might behave and which mixes of different types of AVs that are likely to CoEXist at different stages of the transition period towards full automation.

Assessing traffic safety based on traffic models is difficult and in addition to the traffic performance and space efficiency assessment tool, two different safety assessment tools are developed: one qualitative safety assessment approach, which assess potential safety effects in relation to the accident types and automation functions that are relevant for an infrastructure design; and one more detailed safety assessment approach based on safety inspections. These two safety assessment approaches are not relying on the results of modelling tools and can be used independently.