While I'm a strong proponent of reducing and possibly eliminating car use, this image is disingenuous. They neatly packed 69 (nice) people into a medium bus, sure. But when showing cars, it's almost 1 persons per car (I counted 15 cars in a row and there are 4 rows, so 60 cars). You can definitely use cars more efficiently than that.
Assuming that actually autonomous self-driving cars exist, they could be extremely efficient. Especially if you treat them like ride sharing taxis. In other words, a lot of people could share the same car and that would reduce the amount of owned cars. They also never waste space being parked. So I can see how when we make a real self-driving car, it can potentially reduce traffic. Especially for all those cases where public transportation doesn't work.
And what the heck is a "connected car"?
Things being close together isn't really an issue here because it's just meant to visualize the volume. They are not trying to paint a realistic scenario, I don't think.