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Comment by JumpCrisscross | Hacker News Reader

The next century of personal transportation will be autonomous electric cars for short distances, autonomous regional rail for medium within-density transport (e.g.. interborough or within-the-Bay-Area distances), autonomous electric aircraft for cross-density transport(e.g. New York to the Hamptons or Cupertino to Napa) and cheap windowless airplanes for long distance. The unique aspect of this vision is the reduced role for public transit outside intracity subway and regional commuter rail. Autonomous cars and planes seem to increase road efficiency in a manner that competes effectively with rail for density-crossing transport.

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And this vision is terrible for energy efficiency and space efficiency. Look at developing countries, there's often a large dependence on taxis and three-wheelers, due to the low labor costs the economics are similar to self driving cars in industrialized countries (some scholars predict the cost of cleaning of shared autonomous cars will be substantial, which may make it similar to the drivers cost in developing countries). Meanwhile, the capacity increases are likely oversold, as you can see in developing countries that have poor transit: total grid lock.

Your "Futurama" vision of car-centric cities is old, tired, and not working, throwing the words 'electric' and 'autonomuous' in there isn't gonna chance much.

> the capacity increases are likely oversold

The last study I saw on the topic estimated most urban travel could be accomplished with 11% of the existing fleet if cars drove constantly. So not only do you return all the parking space to the economy, but you also increase roads' capacity by something around tenfold. Throwing "autonomous" in changes the capacity tradeoffs and throwing "electric" in makes more cars more pleasant, from both an emissions as well as noise perspective.

11% seems incredibly unlikely. How is a single car going to get 10ppl (on average!) to work during rush hour. Add in destroying transit, and the kind of sprawl that "Futurama" fantasies tend to come with, and I doubt this is going to work. Many roads are already fully congested during rush, where could a 10x capacity increase possibly come from...

The last studies I heard about talked about reducing the required vehicle Fleet by 3 vor 4, while actually _increasing_ VMT.

> where could a 10x capacity increase possibly come from

Eliminating street-side parking single-handedly gives you 2x to 3x on side streets. Tighter packing and better routing does a lot of the rest. You can't do the latter until a zone goes 100% autonomous, which is unrealistic for e.g. Dallas but very much so for downtown Manhattan.

> Add in destroying transit

Nobody said anything about destroying transit. Earlier, I explicitly mentioned rail for within-density transit.

It you turn parking lanes into driving lanes, you're not increasing the capacity of the existing infrastructure, but creating much more driving infrastructure. It also won't 'return' parking to the economy.

Consider the 'staying quality' of a <parking lane+driving lane+parking lane> residential street turned into a 3-lane thoroughfare. That's exactly the sort of dystopia that new urbanists and sustainable mobility advocates are warning about.

Have you heard of bicycles?

I think there are some that have already begun to attach electric motors to, so yes, we can even replace those as well.

whats great about windowless airplanes?

> whats great about windowless airplanes?

Blended-wing bodies [1] are very efficient. So you get a bigger jet that's cheaper to fly. Downside: some seats will be on the inside. Moreover, windows are a huge stress point on air frames. A windowless craft is cheaper to maintain.

If there's one preference travelers show, it's that for cheaper tickets. A windowless blended-wing aircraft delivers on that.

[1] https://en.wikipedia.org/wiki/Blended_wing_body

It'd be cool if they could have ceiling windows.

One of the biggest issues with further adoption of Blended Wind Body aircraft is that current FAA regs require demonstration that deplaning the aircraft in an emergency is possible at full seating capacity, including crewmembers, in 90 seconds or less [1], although studies and simulations have been done that continue to evaluate this [2]

BWB with their pax on the inside, make this very challenging.

[1] s7: http://fsims.faa.gov/WDocs/8300.10%20Airworthiness%20Insp%20...

[2] https://fseg.gre.ac.uk/fire/fseg_ped2010_bwb_paper_distrib_f...

Nothing

So all the revolutions are schedualed to happen at once. Electric vehicles, planes. Autonomous vehicles. Abandonment of private vehicles. All at once? I think the commitee is overreaching a little. Did i miss a meeting?

I r ally don't get how you're getting the implication that it all lands at once.

These are a basket of solutions for which each country/state will choose some or all but all of which could play a part.

We had Internet, Mobile phones and GPS becoming widely adopted in the same decade, I don't see why that wouldn't be possible.

That being said I don't think they will land and be adopted widely at the same time. I would see electric cars first, then more renewable energy, then self driving cars, then electric planes, all across two decades or so.

Electric planes (at the size of boeing/airbus) are a long way away. In terms of energy density, batteries will have to be far better than diesel fuel if they want to succeed in big aviation. It has to be better because, unlike with fuels, a battery-power aircraft does not get lighter as it empties the tanks, which also means the frame has to be stronger to land at the takeoff weight. This becomes more and more an issue as you scale to larger aircraft. Lithium-ion batteries will never get to this point. Short of some new breakthrough technology, I don't see it becoming a thing in our lifetimes.

The plane being proposed is not purely electrical: it's powered by a turbine, think of a big APU, that powers the EDFs and changes the batteries, which don't need to be large enough to power the whole flight.

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