Developing a vehicle is always a long and complex task. This is especially true for autonomous cars. Tasks performed by the driver are taken over by the vehicle and must be performed with maximum reliability. Developing these systems is a difficult task, especially due to limited testing capabilities. Testing a vehicle in a closed environment is safe and controlled, but the variety of test scenarios is limited. By using mixed reality environments, one can create a diverse environment around a real test vehicle, with traffic, obstacles, and unexpected situations. The real movement of the test vehicle allows testing decision and motion planning level vehicular functions. Information from the virtual world can be considered as input to the vehicle sensor. Mixed reality or digital twin simulation environments can greatly assist the autonomous vehicle development process and also serve as a basis for validation procedures for such systems.This article introduces a mixed reality simulation environment that integrates a real test vehicle into a virtual environment, can handle other real and virtual obstacles, contains traffic simulations, and visualizes all of these.

In response to the changing social demand for safer and more efficient transport in the last few years the development of autonomous driving functions has increased dramatically and in so created many challenges for the automotive industry. Since autonomous driving functions must handle nearly countless traffic participants and various situations, most companies developing such technologies began testing on public roads which became possible due to the amendment of laws in several progressive countries or states worldwide leading the way, for example leading states such as California, The Netherlands and from 2017 Hungary [1]. However, recent regrettable incidences highlight the risks of public road testing and strengthen the role of closed proving grounds and specially designed and constructed controlled urban-like test areas which can represent the real-world environment.

Thanks to the recent evolution in science and technology, road transport is going to change radically. Today vehicle assistant systems help the human driver to manoeuvre the vehicle safely. In the near future connected and highly automated vehicles will also appear on the road in multiple transport modes. Higher vehicle automation levels rely on disruptive technologies that simply cannot be tested and approved in the currently used sustaining technologies format. As validation processes become more complicated they require a more specific and ever-changing test environment. While current autonomous vehicle test environments are developed around activities that mostly concentrate on an urban test area, every single element of the new Hungarian automotive proving ground is dedicated to the testing and validation of connected and automated vehicles. This paper will discuss the design concept, illustrating the unique points that differentiate the new Hungarian test facility from that of a conventional vehicle test track as well as from other current autonomous vehicle testing areas.