The latest chapter for the self-driving car: mastering city street driving

* NTSB review: Airplanes face higher scrutiny than automobiles (despite the lower overall casualty rate). Part of the reason people have grown comfortable with air travel nonetheless is because the NTSB analyzes what went wrong after each crash and recommends (mandates) certain changes. Moreover, as far as government agencies go, the NTSB does its job reasonably competently and independently.

* Gradual introduction: It's unlikely fully self-driving cars will be introduced all at once. What's more likely is the gradual automation of certain driving functions (sort of like cruise control, automatic parking, and other feature sets). I think any system that hands off control from a robot to a human introduces its own safety risks, but you might see something like a dedicated autonomous lane on a freeway with special parking areas where humans can safely resume control for driving in the city. There's also augmented driving where a car is primarily human driven, but will do things like pre-charge brakes and give advanced warning to a human diver when it believes the human is about to screw up.

* Economies of scale: Large business organizations will probably get comfortable more quickly with autonomous cars than individual consumers. If FedEx and UPS support policies like "no left turns," they'll probably be among the first to get on board with fully automated trucks. And you'll certainly see some support for the insurance business, if autonomous vehicles really do result in lower overall accident rates.

Has it even occurred to you there might be any possible cons to your scenario?

First of all, the lot the cars come from is going to require real estate, so subtract that from your windfall. Where will they be at night or other low-use times?

Second, subtract the additional resources in gas/electricity it takes to get to my house from god-knows-where it came from.

Third, subtract the time I'm waiting in my driveway with the kids screaming and my wife in labor for a car to show up from god-knows-where. Or else the premium I'm paying to get ahead of the other guys in the queue. And while we're at it, all of those times that I wanted something from the store 5 minutes before it closes? Guess what, if I can't get a car in time, that's lost productivity. Have to buy lunch from the cafeteria b/c I couldn't get to the supermarket. Unless you're telling me that in order to accept this vision of the future, I have to be perfect and plan everything. Telling me in the future no one will be able to get to the store 5 minutes before it closes is just unrealistic, undesirable and unacceptable.

Fourth, subtract again, the additional energy needed to take the car to its next destination.

Fifth, consider all of the extra cost of adding, servicing, verifying, maintaining LIDAR and servoes to all of these millions of cars. With thousands of dollars of extra parts, they're going to require thousands in extra maintenance, inspection, training and insurance. Yeah, I know that's boring. It's not an interesting technical problem, but that's the reality of motor vehicles. If anyone thinks this won't make the price of vehicles go up significantly, they've never been in charge of anything critical.

I'm not "against the future," it's just that all of these digit-heads are seeing a grandiose signal-processing problem and doing multiplicative math like yours to make it look attractive and not even operating at a practical level whatsoever.

- How many beams you're putting out and at what angles

- How fast you're spinning and how fast you can get the data back.

- How many points of data you can get through your bus

If the Google Car is using the big Velodyne (http://velodynelidar.com/lidar/hdlproducts/hdl64e.aspx), it puts out 1.3 Mpt/second over a 26.8 degree vertical field of view. That makes it put out ~135 pts per vertical and horizontal degree. At a range of 50 meters, with angular resolution of 0.09 degrees and 0.4 degrees vertical resolution, you're looking at vertical spacing of 34.9 cm/pt and a horizontal spacing of 7.8 cm/pt. You'll need multiple "hits" to make an obstacle, and they have to reflect well enough to be counted. A common thing to do is reject any obstacle below a certain height - since it could just be noise.

Debris with cameras is tough because you can't differentiate between "dry spot on pavement" and "someone's dropped a sheet of drywall".

That said, how much toward road maintenance would you say the average commuter pays? You're looking at $214/car/year, according to the FHA and Census Bureau (see, for example, http://www.artba.org/about/transportation-faqs/faqs/#4).

How much more roadway is used by a car than a bicycle? How much less maintenance is caused by a bicycle than a car? (N.B. cars are more than an order of magnitude heavier than bicyclists; trucks are two orders more per axle.) How much do you think a bicyclist's fair share should be? How should it be measured, applied, and taxed?

As for registration, I was under the impression that was more akin to registering a firearm; it's chief purpose is enforcement of laws and property taxes, rather than offsetting the costs of highway maintenance. Is there a state where vehicle registrations are a major source of highway maintenance monies?