Road traffic in South Africa presents some very special challenges: different road surfaces, wildlife on rural roads and many pedestrians in the city as well as in the interurban traffic who often cross lanes completely unexpectedly. Automated and autonomous vehicles have to be aware of these peculiarities and respond in a reliable manner. In the fourth leg of the Mercedes-Benz Intelligent World Drive, the test vehicle - based on the current S-Class series-production saloon - is facing up to South Africa's idiosyncrasies with automated test drives on the roads of the Western Cape and in the city of Cape Town.
The focus of the test drives on the Western Cape is on pedestrian detection in many unfamiliar situations in particular, both in dense city traffic as well as on rural roads. Furthermore, the test vehicle based on the S Class is collecting information for detecting road signs specific to the country, validating the digital map material of HERE MAPS and testing out a prototype of the innovative light system DIGITAL LIGHT.
Many crossing pedestrians in unusual traffic situations
Whether in the city or out in the country – in South Africa, there are many pedestrians on the road. Sometimes they walk on the street and often, they cross lanes completely unexpectedly. In the extremely dense urban traffic in Cape Town, driving is truly a precision task – particularly in narrow streets, where the pavements are mostly overflowing with parked cars on both sides. But even on national roads outside of towns, and on the motorway too, drivers always have to expect to encounter crossing pedestrians. Just as high in number are the accidents which occur. In 2016 some 5,410 pedestrians died in road traffic accidents. That figure represents 38 percent of all road traffic deaths. This pedestrian behaviour calls for an additional, increased level of awareness and thus, also poses particular challenges for the sensor systems of automated and autonomous vehicles. Cameras and radar systems have to detect passers-by and interpret their movement correctly so that the vehicle can react within milliseconds in the event of an emergency.
Incomplete road signs and signs specific to the country
Further special features include traffic signs which are only found in the 15 Member States of the Southern African Development Community, such as South Africa, Namibia, Botswana or the Seychelles. For example, the no stopping sign shows a crossed-out letter 'S' in a red circle, while the sign for no entry is made up of two black horizontal bars in a red circle. In addition, the road traffic signs in South Africa are often incomplete. Intersections where you have to stop are not always indicated by a stop sign – in some cases they only have wide, white lines across the road surface. Warning signs before the commonly-found speed bumps are also not always present, or are positioned close to the obstacle that there is insufficient time to react.
The lack of signs presents a major challenge for the performance of the camera and radar systems as well as the quality of the digital maps, which enable automated driving functions such as the Active Distance Assist DISTRONIC with route-based speed adjustment to function reliably. Validating the latest digital map material from HERE, particularly with regard to intersections where the vehicle would need to stop and traffic obstructions such as speed bumps, is therefore a particular focus of the test drives on the Western Cape.
DIGITAL LIGHT – testing the innovative lighting system
In addition to the features specific to the country, Mercedes-Benz is testing a headlamp prototype featuring the innovative DIGITAL LIGHT technology. This is because light equally has a central role to play on the road to automated and autonomous mobility. The non-dazzle continuous high beam in HD quality uses chips with over one million micro-mirrors, and therefore pixels, per headlamp. As such it achieves ideal light distribution in any driving situation – without dazzling other road users. Furthermore, this revolutionary lighting system makes functions possible that were unveiled as a vision of the future in the F 015 Luxury in Motion research vehicle in early 2015. Among other things it is able to project light corridors onto the road in order to communicate with its surroundings.