  Autonomous cars can perform poorly for many reasons. They may have perception
issues, incorrect dynamics models, be unaware of obscure rules of human traffic
systems, or follow certain rules too conservatively. Regardless of the exact
failure mode of the car, often human drivers around the car are behaving
correctly. For example, even if the car does not know that it should pull over
when an ambulance races by, other humans on the road will know and will pull
over. We propose to make socially cohesive cars that leverage the behavior of
nearby human drivers to act in ways that are safer and more socially
acceptable. The simple intuition behind our algorithm is that if all the humans
are consistently behaving in a particular way, then the autonomous car probably
should too. We analyze the performance of our algorithm in a variety of
scenarios and conduct a user study to assess people's attitudes towards
socially cohesive cars. We find that people are surprisingly tolerant of
mistakes that cohesive cars might make in order to get the benefits of driving
in a car with a safer, or even just more socially acceptable behavior.
