A new white paper from the University of Michigan Transportation Research Institute (UMTRI) discusses issues related to road safety and self-driving vehicles, concluding that expectations for improved road safety may be overblown.
In their paper, Michael Sivak and Brandon Schoettle assessed safety from four perspectives:
- Can self-driving vehicles compensate for contributions to crash causation by other traffic participants, as well as vehicular, roadway, and environmental factors?
- Can all relevant inputs for computational decisions be supplied to a self-driving vehicle?
- Can computational speed, constant vigilance, and lack of distractibility of self-driving vehicles make predictive knowledge of an experienced driver irrelevant?
- How would road safety be influenced during the expected long transition period during which conventional and self-driving vehicles would need to interact on the road?
Of particular note, Sivak and Schoettle pointed out, is that not all crashes are caused by drivers. While an autonomous vehicle could compensate for some crashes caused by other traffic participants (they use the example of a drunk stepping into the roadway), and could in principle respond more quickly than a human, it might not be able to stop in time in all situations because of braking limitations. Another percentage of crashes are caused by vehicle failures, which would also not be addressed by autonomous drivingand hat expectations that they would be less frequent with self-driving cars are not realistic.
The paper by Sivak and Schoettle draws four conclusions:
- The expectation of zero fatalities with self-driving vehicles is not realistic.
- It is not a foregone conclusion that a self-driving vehicle would ever perform more safely than an experienced, middle-aged driver.
- During the transition period when conventional and self-driving vehicles would share the road, safety might actually worsen, at least for the conventional vehicles.
The UMTRI paper, Road Safety With Self-Driving Vehicles: General Limitations and road Sharing With Conventional Vehicles can be accessed here when it releases publicly.