When the roads have 5 lanes each direction, we need greater social cohesion to set up differentiated cruising and passing. The majority of people prefer to have

When the roads have 5 lanes each direction, we need greater social cohesion to set up differentiated cruising and passing. The majority of people prefer to have more open space directly ahead of them (unless impaired enough to want to follow someone else's lead or having trouble with nighttime visibility), so they sort of spread out.