Level of Service Definitions: Deliverable D3

The Level of Service (LoS) is a widely employed metric that quantifies the performance and quality of a provided service, utilizing a predetermined scale. In the transportation domain, road capacity (i.e., maximum throughput in a given road section) is the most widely used performance indicator, where the LoS is applied. In road capacity studies, the LoS definition is dependent upon the specific context and facility under examination, such as urban areas or motorways. In urban settings, the criteria typically employed for determining LoS include average travel speed, average travel time, frequency of stops, and delays. Conversely, on motorways, LoS is determined by factors such as vehicle density, traffic speed, and frequency of lane changes (HCM, 2016). Upon specifying the context, the chosen criteria are applied, and threshold requirements are established to categorize the performance and quality under the appropriate LoS. The LoS scale can range from binary levels (e.g., acceptable or unacceptable) to more nuanced scales. For instance, the HCM (2016) employs a six-point scale (A = very good; B = good; C = acceptable; D = bad; E = very bad; F = system breakdown). For C-ITS services (i.e., information provision), however, the aim is to provide information that are, among other things, accurate and timely to the road users, connected and autonomous vehicles, so they can react accordingly to events on the road network. The CAV-ready framework (CRF) developed in WP3 aims to illustrate the progress of National Road Authorities (NRAs) towards becoming a digital authority, meaning that the NRAs should provide traffic related information (data provision) to its users (connected and autonomous vehicles) that are precise, accurate, and timely. As such, we have defined three distinct LoS categories: Basic: Minimum acceptable performance/quality Enhanced: Not optimal but sufficient performance/quality Advanced: Ideal or best performance/quality