"But it will not need to recognize pedestrians and bikers and human driven cars"

If they want to land at some point presumably they have to avoid landing on these things?

As well as trees, birds, powerlines, antennae, and even locusts!

Flying cars might or might not happen (see other discussions here). However they will never be more than a niche. Airplanes need far more safety space than cars. For a car you need a few dozen meters to the cars front and back, and less than 1 side to side. For airplanes it is thousands of meters in all directions, and you are limited as to height before you run out of atmosphere. So even thought planes run in 3d space, there is in practice less space for them than the few roads in a city.

Humans and bikes need even less safety space than cars.

I don't think safety space is a good criterion for predicting how widespread a means of transportation will become.

A fast mode of transportation, with a large safety space requirement, may be more efficient than other modes and/or become popular.

The point is there isn't enough space for all the [single occupancy] cars to become airplanes. Speed doesn't change that because speed increases the space needed between airplanes.

Now if we change to flying buses we might be able to pull something off, an express bus that picks up people for a few stops in the suburb for 10 minutes, then flys at >150mph downtown is a very compelling competitor to a car and will get anybody who currently drives 20 to minutes downtown to ride if the cost is reasonable (those in closer in suburbs will still drive). I don't think the business or environmental models work out.

>IMO, flying cars will eventually arrive.

Not so sure. I saw specific designs hyped in the 80s and 90s, and know of efforts hyped in the 70s as well. The reason they always fail is because constraints of designing a car to go on land and the constraints of designing a flying machine are different. You can sorta kinda build something that does both, and people have, time and again, but it will be good at neither of those things. Well, unless we develop "antigravity" or something...

Add the possibility of huge damage caused from a failing/failing/crashing flying car, not just to the road and other cars there (like with a car) but to any building, group of people, etc. If it was a car-replacement (and thus getting on it was laxer than flying a plane, with flight plans, airport checks, special licenses), it would also be perfect for suicide terrorism too!

Here's a funny but insightful post I've found, hammering on the topic:

Listen to most discussions of flying cars on the privileged end of the geekoisie and you can count on hearing a very familiar sort of rhetoric endlessly rehashed. Flying cars first appeared in science fiction—everyone agrees with that—and now that we have really advanced technology, we ought to be able to make flying cars. QED! The thing that’s left out of most of these bursts of gizmocentric cheerleading is that we’ve had flying cars for more than a century now, we know exactly how well they work, and—ahem—that’s the reason nobody drives flying cars.

Let’s glance back at a little history, always the best response to this kind of futuristic cluelessness. The first actual flying car anyone seems to have built was the Curtiss Autoplane, which was designed and built by aviation pioneer Glen Curtiss and debuted at the Pan-American Aeronautical Exposition in 1917. It was cutting-edge technology for the time, with plastic windows and a cabin heater. It never went into production, since the resources it would have used got commandeered when the US entered the First World War a few months later, and by the time the war was over Curtiss apparently had second thoughts about his invention and put his considerable talents to other uses.

There were plenty of other inventors ready to step into the gap, though, and a steady stream of flying cars took to the roads and the skies in the years thereafter. The following are just a few of the examples. The Waterman Arrowbile on the left, invented by the delightfully named Waldo Waterman, took wing in 1937; it was a converted Studebaker car—a powerhouse back in the days when a 100-hp engine was a big deal. Five of them were built.

During the postwar technology boom in the US, Consolidated Vultee, one of the big aerospace firms of that time, built and tested the ConVairCar model 118 on the right in 1947, with an eye to the upper end of the consumer market; the inventor was Theodore Hall. There was only one experimental model built, and it flew precisely once.

The Aero-Car on the left had its first test flights in 1966. Designed by inventor Moulton Taylor, it was the most successful of the flying cars, and is apparently the only one of the older models that still exists in flyable condition. It was designed so that the wings and tail could be detached by one not particularly muscular person, and turned into a trailer that could be hauled behind the body for on-road use. Six were built.

Most recently, the Terrafugia on the right managed a test flight all of eight minutes long in 2009; the firm is still trying to make their creation meet FAA regulations, but the latest press releases insist stoutly that deliveries will begin in two years. If you’re interested, you can order one now for a mere US$196,000.00, cash up front, for delivery at some as yet undetermined point in the future.Any automotive engineer can tell you that there are certain things that make for good car design. Any aeronautical engineer can tell you that there are certain things that make for good aircraft design. It so happens that by and large, as a result of those pesky little annoyances called the laws of physics, the things that make a good car make a bad plane, and vice versa. To cite only one of many examples, a car engine needs torque to handle hills and provide traction at slow speeds, an airplane engine needs high speed to maximize propeller efficiency, and torque and speed are opposites: you can design your engine to have a lot of one and a little of the other or vice versa, or you can end up in the middle with inadequate torque for your wheels and inadequate speed for your propeller. There are dozens of such tradeoffs, and a flying car inevitably ends up stuck in the unsatisfactory middle.

Thus what you get with a flying car is a lousy car that’s also a lousy airplane, for a price so high that you could use the same money to buy a good car, a good airplane, and a really nice sailboat or two into the bargain. That’s why we don’t have flying cars. It’s not that nobody’s built one; it’s that people have been building them for more than a century and learning, or rather not learning, the obvious lesson taught by them. What’s more, as the meme above hints, the problems with flying cars won’t be fixed by one more round of technological advancement, or a hundred more rounds, because those problems are hardwired into the physical realities with which flying cars have to contend. One of the great unlearned lessons of our time is that a bad idea doesn’t become a good idea just because someone comes up with some new bit of technology to enable it.

When people insist that we’ll have flying cars sometime very soon, in other words, they’re more than a century behind the times. We’ve had flying cars since 1917. The reason that everybody isn’t zooming around on flying cars today isn’t that they don’t exist. The reason that everybody isn’t zooming around on flying cars today is that flying cars are a really dumb idea, for the same reason that it’s a really dumb idea to try to run a marathon and have hot sex at the same time.

https://www.ecosophia.net/progress-and-amnesia/

The question is whether the problem is one of insufficient engineering optimization or whether it requires a step-function in technology that does not exist now. It appears to me that self-driving cars are of the former type, while flying cars are the latter.

Current-resolution lidar, cameras, and radar seem to provide sufficient sensor input. The costs are too high by a long shot, but that may just be a question of getting economies of scale established. Current PC graphics hardware has sufficient bandwidth to process those sensors. I don't think you can just throw current neural net training at the problem and get Type 5 autonomy out of it - there will be lots and lots of engineering hours in figuring out what to do with that sensor data - but that's just a problem of doing many man-years of straightforward work.

Flying cars don't have adequate power from a current-gen internal combustion engine running on petroleum, and especially not enough power from lithium-ion batteries and electric motors. If you could get a power source that provided an order of magnitude or two greater power density than the best of those technologies, flying cars would be viable. Until then, no amount of engineering hours will make it work.

> If you could get a power source that provided an order of magnitude or two greater power density than the best of those technologies, flying cars would be viable.

So essentially thousands of flying nuclear reactors piloted by average joes around the city.

That sounds really safe!

> To cite only one of many examples, a car engine needs torque to handle hills and provide traction at slow speeds, an airplane engine needs high speed to maximize propeller efficiency, and torque and speed are opposites

You can get around that by using an electric transmission. A turbine drives an alternator which drives 2 sets of electric motors one for the wheels and one for the propellors. As to the rest of the post it’s attacking a straw man. I don’t think people want a highway capable car that can also fly. If you can fly why drive on the highway?

A 50k to 100k VTL ‘flying car’ with maximum cruse speed of 80 MPH, maximum altitude of 10,000 feet, a range of 500 miles, room for 2+ people, and a cargo capacity of 1,000lb including people fits most people’s definitions of a flying car. Being able to move around on the ground at say 15 to 25MPH without giant spinning blades would also be a great feature.

Oddly enough I think we already have something close to flying motorcycles in autogyros, but the closest thing to a flying car is a vanilla small flying airplane and those run you 250k new.

PS: There is even something of a jet pack alternative https://www.youtube.com/watch?v=bpwd-T2Qvbk

Agreed on flying cars, but I wanted to point out a glaring inaccuracy in the opening that undercuts the author's broader argument:

"By 2000 or so that curve had flattened out in the usual way as PV cells became a mature technology, and almost two decades of further experience with them has sorted out what they can do and what they can’t."

In fact, PV prices have dropped DRAMATICALLY since 2000 (https://www.sciencedirect.com/science/article/abs/pii/S03014... looks at the different trends 1986-2001 and 2001-2012), as have the prices/performance of the energy storage systems needed to make them practical.

I agree that it's not a silver bullet that will solve the fossil fuel crisis all on its own (at least not in time), but it is in line with the broader improvement in renewable costs and efficiency.

>In fact, PV prices have dropped DRAMATICALLY since 2000 (https://www.sciencedirect.com/science/article/abs/pii/S03014.... looks at the different trends 1986-2001 and 2001-2012), as have the prices/performance of the energy storage systems needed to make them practical.

Can't open this, but the abstract also shares this:

"Market-stimulating policies were responsible for a large share of PV's cost decline"

This part is artificial though (subsidies, etc).

The subsidies created the scale and experience required to lower the costs; they're not included in the cost numbers. With current technology, they are cheaper without subsidies.

I read that in various places, but I'm still suspicious. There are lots of ways to hide subsidies (green tax cuts for example).

I wonder if it's possible to solve noise problem with flying cars. Maybe use active noise cancellation at the source?

No idea if it's even theoretically possible, but would be neat.

No, it's not physically possible to do any significant active cancellation of the noise caused by a rotor / propeller spinning through the air. The noise sources are too spread out (especially with multi-rotor designs) and cover too much of the audible range.

Blade shape can be tuned to an extent for minimizing noise but that also reduces efficiency (not much to spare). Larger, slower turning blades are also quieter but there are practical physical limits on size and weight.

Aren't flying cars going to be much noisier than surface cars?

Joby is using some low noise props that are very effective. Quieter than most of the ridiculous motorcycles and loud cars on the 101.

If we care about noise, we should be addressing the motorcycle industry. I can’t hear a C-130 flying overhead at 1000 feet when I am in my house, but I can hear motorcycles zipping by on the freeway behind my house.

Yes, that was my point. We will need some clever tech to make the noise bearable.