# Non-Compliant Behaviour of Automated Vehicles in a Mixed Traffic Environment
## 3 Implementation of Automated Driving Functions in Microscopic Simulation  
The automated driving functions described in this paper were developed for the microscopic traffic simulator PTV Vissim (Vissim 2022, service-pack 0.6. ), in particular for multi-lane motorways including on- and off-ramps. PTV Vissim provides an external driver model DLL interface that enables the implementation of additional driving functions using the programming language C/C++. This enables the generation of diverse mixed traffic scenarios using the Vissim internal driver model, which represents human-driven vehicles together with self-developed automated driving functions to investigate the impact of automated driving on the entire traffic flow. In other words, one can analyze mixed traffic situations and test new concepts of automation and newly developed traffic management strategies, including different penetration rates of conventional and automated vehicles. The design phase focused on specific characteristics of automated driving functions, based on the taxonomy SAE J3016 [33], that are expected to have an effect on traffic efficiency in the future. These characteristics were considered during the development of automated driving functions, in order to investigate the tactical behavior of different levels of automation in diverse traffic scenarios. The driving functions provided an initialization file to adapt AV driving behavior parameters according to the simulation study. This enabled an analysis of the impact of specific parameters for automated vehicles on the entire traffic flow. First, we assumed all AVs were in a connected (C) environment. The communication process and the corresponding technologies were not modeled, but the AVs were assumed to be able to receive and communicate their current state (position, speed, acceleration) among other vehicles. This means that connected automated driving functions are able to consider vehicles in their maneuver planning strategies that are not within the range of the vehicle's perception system. Three different AV driving functions were developed for the simulation studies. Depending on the driving function, lateral control is achieved either by the AV driving function or by the Vissim internal lane-change model that represents human driver behavior (see Table 2). For ACC equipped AVs, only longitudinal control is executed by the developed AV model. Lane-change maneuvers are planned and controlled by Vissim. Since all AVs are in a connected environment, this driving function is referred to as C-ACC. Additionally, we introduce a Connected Highway Chauffeur (C-HC), for which longitudinal and lateral control is executed by the AV driving function on main roads. Hence, C-HC-equipped vehicles are not capable of performing mandatory lane changes (e.g., merging at on-ramps), and these maneuvers are executed by Vissim. This reflects AV systems that can be activated after the merging maneuver from the on-ramp to the main lane of motorways. In contrast, a Connected Highway Pilot (C-HP) controls longitudinal and lateral behavior on the open road, as well as in merging and diverging areas. All parameters, which can be changed in the initialization file, used to investigate a specific automated driving behavior are summarized and described in Table 3. The implementation of the automated driving functions within the dynamic link library (DLL) followed a modular architecture comprising four core components: trajectory planning, handling of non-compliant trajectories, trajectory evaluation, and maneuver execution. Each of these modules is described in detail in the subsequent sections.