> Commuting nowadays is broken. People commuting by car are hauling around 4 or more empty seats at 30 km/h along a highway full of other people doing the same, going into the same cities often into the same office districs. We could get rid of a lot of cars if we didn't drive around 4 empty seats and filled just one.

Unfortunately, highways require a certain minimum vehicle size. The best you could possibly do is have a short coupe with 2 seats. It wouldn't significantly influence the size of the vehicle but waste more resources for the few times where you need a 3-4 person vehicle. The savings to be had are way too slim. However, driving a pick up truck for your commute is absolutely a waste of resources because there are smaller and more aerodynamic cars that are commute worthy.

>Or if we lived closer to where we worked but that's seems like a more complex problem.

It's the only solution. Building a von Neuman architecture style city is absolutely stupid for society since the world is inherently parallel. There is no logical reason to have massive central work place districts. Each office building is a cpu core and each residential building is a memory chip in its own right. We don't need to put all the cpu cores next to each other and put the memory somewhere else. A distributed development pattern is significantly more efficient since data and computation are next to each other.