&gt; Do we really have excess capacity compared to the peak demand? Put another way, how many people own a car and aren&#x27;t using it at e.g. 8:50AM? At a complete guess I&#x27;d say maybe 5%?<p>As I said, when I look out at my residential street at 8:50, I see about half of the cars still parked there, or maybe a third (very rough estimates, I haven&#x27;t actually counted). Now, I do live in a city with good public transit options, that&#x27;s also fairly walkable and bikable. But at least where I live, there&#x27;s a pretty serious oversupply of capacity, just because people do need cars occasionally and the options for not owning a car are not good enough.<p>In fact, on the next street over, parking goes way up at around this time since I&#x27;m near a major subway stop, so a lot of people park here and take the subway the rest of the way in. Rather than just sitting there, going back up and shuttling more people to the subway would be a more efficient use of cars that you could do with self driving cars. The commutes from house to subway station are likely under 30 minutes, and since rush hour generally actually lasts about two hours from 7 AM to 9 AM, you could fit a couple of round trips in that time period.<p>&gt; (Also, given zoning and city layout, most houses are a lot more than 5 minutes away from most offices. Even if my commute is 8:20-8:50 and yours is 9:15-9:45, we&#x27;re probably both heading into the city centre from outside, so the same car probably can&#x27;t serve us both).<p>This is increasingly untrue. Mixed use developments, companies moving out to the suburbs for cheaper real estate, people moving back in to the city, and so on mean that reverse commutes are increasingly common.