More, fewer or different risks?
The majority of road accidents are caused by human error. At first glance, this would suggest that automated vehicles are safer than those driven (only) by humans: automated vehicles do not drive under the influence of alcohol or drugs, do not fall asleep, cannot be distracted, observe speed limits and maintain minimum distances. At the same time, however, automating vehicles also creates new risks. On the one hand, driver assistance systems can perform many routine tasks more effectively than a human driver. For example, optimum braking, keeping in lane or judging the distance to other road users. On the other hand, they do not possess all the skills at the disposal of an experienced human driver – at least not yet. This is particularly evident in complex situations where a quick reaction is needed and the driver has to choose between several hazards. Even the best program for controlling driver assistance systems cannot predefine every potential set of circumstances arising on the road.
To complicate matters further, numerous legal systems have to be taken into account when programming extensive automation of vehicles: after all, vehicles regularly cross national borders. Even standardising legal requirements in the EU or between US states is difficult, lengthy and will probably never be entirely comprehensive. On a global scale, such standardisation is unlikely to be realised in the foreseeable future. Consequently, the vehicle itself must detect when it crosses a national border and adapt its driving behaviour in accordance with the local legal system. Finally, errors in the programs controlling the driver assistance systems can cause accidents which would not have occurred had they not been in use. Also, the more automated vehicles are connected to other systems, the higher the impact of typical cyber risks. Hackers, for instance, could access the on-board computer and cause an accident. Or the data collected by an on-board computer to control a vehicle could be accessed and misused by unauthorised parties.