Automated Vehicles: A Review of the Road Safety Implication as Drivers of Change

Road safety is a major issue in a great number of countries around the world. Advanced technologies are in place to reduce the road hazards. These technologies include the overall automated vehicles (AVs) as a part of an intelligent transportation system. The arrival of AVs will produce changes to society as great those followed the introduction of the car more than 100 years ago. This paper highlights the working mechanism, advantages and disadvantages of these technologies in the light of safety improvement, especially on highway or freeway facilities. This because in the early stage of AVs implementation, traffic composition will be mostly manually-driven vehicles with several vehicles with automated driving functions and some AVs. It becomes significant to study the key associated road safety issues when AVs with different settings are mixed in traffic. To address the aim of the research, it has been performed a wide recognition of the actual state of development about autonomous vehicles, on-road automated motor vehicles or fully automated cars. All the literature and studies consider only speculative approach; so it was useful to do a strong meta-analysis in order to catch the overall coherence or evaluation that characterize each kind of AVs stakeholders. An AVs is able to increase capacity (C), the maximum service flow rate (MSFi), the rebalance for unfamiliar driver population (fP), the passenger-car equivalent (PCE), or the proportion of heavy vehicles (PT). According to some authors, AVs may offer much reduced perception and reaction time, tight car-following, precise lane keeping, correct assessment of gaps and crisp lane changing, no erroneous or unnecessary lane changes, and route familiarity. In other words the highway capacity to transport people will increase. All of these factors face to a very strong CMF. It would led to a new definition of the accident risk or accident taxonomy. Moreover, thanks to uninterrupted flow facilities, it has been set some factors describing drivers’ behaviors towards lane and shoulder widths, etc. However, AVs is not sensitive to these factors due to its navigation, LIDAR and programmed car-following systems. A weakness is that current traffic forecast models do not recognize the impact of AVs; so it was interesting to discuss about a new type of CMF. The AVs technologies already represent the border of a new road safety paradigm. Many features deal technical details and others face ethic or legal skills. It also should be considered that to achieve the optimal combination of control (safety) and performance (capacity) in an AVs is definitively a non-trivial problem.