By: Tom

Tom — Tue, 14 Oct 2008 20:10:53 +0000

You’re right, of course — Ryan was also kind enough to reply to this post, and in comments at his place I had to quickly admit that I was looking at the parking situation in too simplistic a manner. I still think that it’s an open question as to whether automated cars will positively impact the overall question of density, but I’m now convinced that they’ll at least let us spend less land on parking lots.
One more thought I’ll add: it will be interesting to see how such a system will be implemented securely. Once cars begin to be able to impel each other to move around some pretty insidious exploits could arise. It should certainly be possible to engineer solutions to this sort of problem, but it’s still a pretty interesting technical problem (as are the parking lot-reordering algorithms themselves).

By: Tim lee

Tim lee — Tue, 14 Oct 2008 19:53:37 +0000

So long as that’s the case, it’s hard to see how self-rearranging, super-dense parking lots can be made to work.
This doesn’t seem too hard to imagine. The easiest way is to just have parking lots with a human-driver section and a robocar section, with the robocar section having smaller, more densely-parked parking spaces. But even that shouldn’t really be necessary. If self-driving cars have a way to signal their robot-ness to other cars, they can automatically cluster in higher density when they find themselves adjacent to one another.
But I actually think higher parking densities is a lot less important than the shift from ownership to taxi rental. This is a positive development for three reasons. Most obviously, taxis are shared so the total number of vehicles in circulation goes down. Second, taxis spend a lot more time on the road so they don’t need parking very much. Third, taxis don’t need to park anywhere in particular, so when they do have to park (which will be mostly in the middle of the night) they can go where the parking spaces are, which means much more efficient utilization of existing parking spaces.
Privately-owned cars require several parking spaces per car, because people expect a parking space at home, a parking space at work, a parking space at the mall, etc. Outside of the densest cities, today’s parking spaces sit empty the vast majority of the time. In contrast, taxis require fewer than one parking space per taxi, because at any one time significant numbers of taxis are out and about.
Finally, something I didn’t talk about too much in the article but I think is probably true is that I’m not sure that the concept of “parking” really makes sense in a self-driving world. Right now, most urban roads have one lane in each dierction (we don’t think of them as lanes, but they are) for parking and 1-3 lanes in each direction for traffic. In a self-driving road, one can imagine a dynamic process where the mix of parking lanes and driving lanes gets adjusted gradually over the course of the day. On a six-lane road, all six lanes might be devoted to traffic during rush hour, while in the middle of the night 4 of the lanes might have cars “parked” in them (two rows of car double-parked in each direction). The total number of cars in circulation doesn’t change day-to-day, so if most of the cars are on the roads during rush hour, it follows that there should be enough spare capacity that they can all “park” on the roads in the middle of the night.
This is obviously highly skeptical, but I think there’s clearly more going on than the mere fact that self-driving cars would pack parking lots more densely.

Comments on: at the mercy of the autobots

By: Tom

By: Tim lee