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The Future of Ground-Based Transportation Systems (swiftprt.com)
146 points by Brajeshwar on Dec 4, 2011 | hide | past | favorite | 97 comments



I really like the idea of a fleet of computer-controlled electric cars that function like an on-demand taxi service.

Think about it, you need to leave for work at a certain time? Just jump on Google Taxi (I use Google as they're the only company that has working driverless cars that I'm aware of at the moment), log-in using your account (that you either pay per ride, weekly, monthly, yearly, yearly+ etc.), calculate your commute, and reserve a car to show up at your house at that time and place. It takes you to your destination then shoots off to an electric or hydrogen-based fleet of these cars standing by at charging facilities in neighborhoods and cities all over the world. If they became ubiquitous enough you could have as little as a five to fifteen minute wait for a car.

However, I think the auto industry would fight like hell to keep this kind of system off the roads as it would severely dent auto sales. I mean hell, I know I wouldn't want a car if I could just have a subscription to a car. Especially if it wasn't just like Sedans. Imagine being able to rent a truck immediately at a moment's notice, then ride back home in a Sedan, all without having to worry about driving anywhere?

That's a world I would like to live in. Then once populations reached the 5,000+ ppl/km2 we could start building mag lev rails and get more into that kind of public transportation.


I love this future because it completely routes around the public transportation dilemma we have in the US. The fact is that automated electric vehicles on paved roads would work perfectly here, could completely replace personal cars, would provide huge cost savings, not to mention saving thousands of lives a year from traffic deaths alone.

And this is something we could actually do. The government could take $X billion, get a cost-effective robotic car platform off the ground, start replacing vehicles on a 1-to-1 basis, and outlaw manual driving on public roads inside of 20 years. It would make existing electric vehicle technology perfectly suitable for trips of any length, since you can simply change cars at the charging station and be on your way inside of a minute. Completely feasible.

But alas... Inertia.


Automatic, cooperative routing also has great benefits over greedy time-minimising routing. In addition to the micro-level benefits (no stopping at traffic lights, fewer traffic waves) there are network-level benefits because the Nash equilibrium of user-optimal routing can be really crappy.

I highly recommend reading about Braess' Network Paradox for a great illustration of this.

http://en.wikipedia.org/wiki/Braess%27s_paradox


Well, the benefits of a private fleet of robotic cars is the ability to have many different providers - so I wouldn't want the government to have anything to do with it, save for setting safety standards for robotic vehicles.

There is no need to try and dictate the type of fuel, either.

But I'm interested to understand why people think a robotised taxi service would be much cheaper than human-driven taxi service. Is the driver really the highest marginal cost in the system? Does removing a driver really drive costs down that much? I wouldn't have thought so.

Oh, and your desire to ban manual driving is never going to fly. The most you would want is perhaps dedicated driverless roads where you aren't allowed to drive - much like bus lanes are now. That would allow for higher speed possible if computer systems can show they can safely transport occupants (or goods) at speeds higher than human drivers.


>But I'm interested to understand why people think a robotised taxi service would be much cheaper than human-driven taxi service.

The overall cost of the system would be cheaper because you don't need as many cars. A human taxi service has tons of taxis sitting around doing nothing for some amount of time, parked somewhere when not in use, etc. If taxi were just an automated service you would just need enough cars to cover peak usage and you'd have more cheaper options on parking (e.g. parking can be LIFO, no need for each car to have exit access at all times).

>Oh, and your desire to ban manual driving is never going to fly.

I disagree. Once automated cars start gaining traction it will be pretty easy to make commercials of crying mothers talking about how they wish their star football player son had only taken an automated car, coupled with real traffic statistics. In a 100 years people are going to find the fact that we used to manually drive cars insane.


Horses were more dangerous than cars, but you're still allowed to ride horses on the road. A total ban on manual driving is just not feasible in a democratic country. I agree that it's possible some roads would be automatic-only, but you're not going to get a ban on cars being driven by people.

You would need just as many robotic cars as you would current taxis. The demand shape isn't going to change just because you remove the driver. Yes, parking and other things will improve but it's going to be a small improvement, not an order-of-magnitude jump.


>Horses were more dangerous than cars, but you're still allowed to ride horses on the road.

They may have been at some point, but that hasn't been the case for some time.

>A total ban on manual driving is just not feasible in a democratic country.

I disagree. Maybe not this generation, but supporting manual driving makes the whole system less stable unless you make a road just for them, which is really expensive.

>You would need just as many robotic cars as you would current taxis.

I don't believe this is the case. I see taxis sitting empty for hours. In that time one taxi could have made several short trips. I'm certain that a computer calculating routes, etc., could manage to get the same work done as is being done now with less resources. That's why we made them, after all.


"Is the driver really the highest marginal cost in the system? Does removing a driver really drive costs down that much?"

Absolutely. In Austin, we have car2go, a car sharing program that allows one-way trips. Gas, insurance, maintenance, parking, and any other cost you could think of is included in the price. It costs about six dollars for me to drive downtown from my apartment. A taxi costs $15.

This isn't a perfect comparison since I walk to a car2go, but a self-driving car might need to drive to pick you up. It's pretty close, though.


Maybe the driver does add a significant cost from your example. I suspect this varies from city to city, as some cities have strict driver requirements (ie, London) while some others seem to just employ anyone with a pulse.

Another cost the car2go scheme is missing is the taxi licensing scheme, which most local governments use as a cash-cow by restricting supply and charging high recurring fees.

Add the fact that most robotic-trips are not going to be two-way and you're probably getting closer to $10 dollars for that trip, which, undoubtedly is still cheaper than with 'wetware' behind the wheel - but some people seem to be thinking this would be as cheap as mass transit, which to me is just wishful thinking.


If I can use China as an example, then in my experience, yes, the cost of the driver makes a huge difference. However, I am not entirely certain if the government is subsidising anything.


I think a lot of that will happen.

But what technologies power the vehicles or enable the roads are secondary. The efficiencies gained by reducing vehicle size will slash costs.

A great many people will commute in a single seat vehicle with 50 horsepower if its a quarter of the cost per mile. Especially if they aren't stuck with it the rest of the time. As long as they can just as easily get larger vehicles for other occasions.

As far as alternatives to conventional roads, we already have them in major cities. Some are elevated and some are underground. Today only mass transit uses them, but I fully expect robotic cabs to destroy mass transit. Even people who don't value convenience will ultimately go for them. So subways and elevated railways, once abandoned by trains, will be converted so they can be used by individual vehicles.


I disagree. See "one lane road" problem. Throughput will be very low and average speeds for urban areas will be close to that of bikes, at best, unless you're doing on/off ramps.

Also, re: many smaller cars... who will purchase/maintain all those? We don't have the infrastructure to support that on many levels.

Personally, I think a system like that in /I, Robot/ is much more likely.


People will operate businesses that own their own cabs or individuals their own personal vehicles. Just as we do now.

And the infrastructure we have now will continue to operate.

How will such an infrastructure be built and be operated. Its a mystery. But its already been done by private enterprise.

As to why only one slow lane could be used, I don't see why that would be. Perhaps you could explain. We have many lanes operating now and robotic vehicles would simply use the same lanes.

Perhaps PRT has these limitations. Robotic vehicles that operate like the vehicles that operate like the vehicles we already have wouldn't.

Of course, we do not yet have robotic vehicles that can be trusted to operate in rain or other extreme conditions and that can discern their environment well enough to be safe.

But once we, there's no reason to follow the PRT pattern. We'll simply follow the patterns we already have. Only with much more sharing (cabs) and much more efficiency.


This is a great point that I haven't heard yet. Reducing the cost by a factor of 4 might be a bit to optimistic though.


It may very well be overly optimistic.

But many features of today's automobile are there because of human needs for performance. Optimize for efficiency for a moped-like 3 wheeled vehicle and you may get something completely different.

  http://www.niutoday.info/2011/09/14/supermileage-team-proves-nation’s-best-again/
I'm not saying cars will actually be like this, but robotic vehicles won't need mirrors or more than one seat or even a steering wheel. A lot of things are could change.


Absolutely. And your comment doesn't even mention the tens of thousands of lives that could be saved yearly, nor the millions of acres of paved wasteland that could be re-claimed for use by humans and real human communities.

I hope someday an america jammed to the gills with empty, idle hunks of steel looks as bizarre and wasteful as it actual is.


Surely that material can be recycled?


Once you switch over to autonomous taxis, so many possibilities open up:

Imagine eliminating most visible parking. A small fraction of the world's vehicle fleet is in use at any given time; the rest of the time it's taking up a parking spot. Remove that and we can have wide sidewalks and bike lanes, parks and new development. Suburbanites get an extra room in their house and a bigger yard.

Buses and light rail become obsolete, but heavy rail transit becomes much more practical, because the door-to-door problem is solved. A virtuous cycle of improved convenience, leading to greater ridership, leading to more trains and shorter headways could result. It makes a lot more sense to ring the bay with a 150 mph train when getting to and from the train is easy. (Then again, it might be easier just to run the taxis at 150 mph on dedicated roads.)


You could get rid of passenger trains and just have the cars drive right in when they chose a train route.

Also, for parking, we can take advantage of LIFO. Today, every single car has to be able to get out independent of the others. With robot cars only the last one of a given type (e.g. van, pickup, sedan).


I love hunky-doodle blue-sky plans too - they don't have to deal with reality.

In reality, most people leave for work at the same time. So they all need a car at the same time. So we need the same number of cars as we have now.

Carpool? Did I hear somebody say carpool? With robotic drivers that works ... exactly as badly as it works now. My three nearest neighbors work in different TOWNS, not only different buildings or neighborhoods.

So I jump on Google Taxi, log in, reserve a car to show up and ... it says "next available taxi arrival, 2 hours before or after desired time". So I either get up at ass-oclock in the morning, or am chronically late for work. </rant>


You can do all of this right now either using a shared vehicle service (you drive) or getting a car + driver (whether limo or taxi). I'm curious as to why people think that robotising a car would lower the cost of hiring dramatically to the point where you were using it to get to work?

It's my understanding that a taxi driver isn't the major cost in a taxi fare, and that fuel, capital cost + licence costs are the principal component in a taxi fare.

I doubt this sort of thing would make much of a dent in car sales, at least that wasn't offset by sales of the automated cars.

The biggest category for sales of cars is for people who regularly feature a combination of long & short drives in their life. This is typically not your average city-dweller, despite having larger numbers of people within cities. The average mum+2 kids isn't going to trade the family car in any time soon for this type of service, not when the cost of keeping and running an average family car isn't really that burdensome.


A 3 mile cab fare in Berkeley is $20+. The all-in cost of driving a basic private car is around 55 cents a mile (or 90 cents for a BMW). That only leaves license cost, so unless you need a $500,000 medallion, the rest goes to the driver. (And as long as the driver works for himself, the medallion is a capital investment which he can sell later.)


But the cost of taxi licences is significant in many cities. I doubt any local/state/federal government is going to let the possibility of driverless taxis proliferate without similar licensing schemes.

I agree that having a car running privately is a lower per-mile cost, but that discounts the number of 'dead' miles that a for-hire car drives - the private car always takes the person where they want to go, while ordering one up via the internet is going to at a minimum double the per-mile cost, because only half the miles (as an average) will be utilised. The car will also not always be in use because demand will never be that smooth, so the in-demand times have to be priced higher to make up for the quiet times. Then there has to be a higher insurance cost, plus a margin to cater for damage to the cab, booking systems, marketing, etc etc.

It's not that hard to see where a cost goes from the 50c/mile to the ~$4/mile which isn't far under the taxi cost.

Taxi drivers make just over minimum wage in most places. While the taxi (plate) owner does make a decent return if run well, it's not like there are a pile of taxi billionaires around. I'm just not convinced removing the driver is going to change the cost by an order of magnitude.


Well, like you said, the fare has to make up for the time the driver is idle, so that problem goes away. Licensing is done to ensure passenger safety, and sometimes to restrict supply. The computer is not going to drive drunk or kidnap you, and excess unproductive machinery can just drive itself to a city where there is more demand.

And the dead miles problem is not a big factor in places like Manhattan where utilization of taxis is high. If this system were pervasive, you could simply maintain a car or two per block.

The biggest issue would be dealing with the peak demand. Fortunately, heavy rail is complementary here, and it's only marginally less convenient when you have quick on-demand service to and from the train station. Demand-based taxi pricing would sort things out.


Automated taxis will be cheaper and more convenient than owning a personal vehicle. The taxi driver is a significant cost.

If you're sharing a car, you're paying a smaller share of the capital costs. Most people don't do that today because it's inconvenient. If cars drove themselves, it'd be convenient.


> I mean hell, I know I wouldn't want a car if I could just have a subscription to a car. Especially if it wasn't just like Sedans. Imagine being able to rent a truck immediately at a moment's notice, then ride back home in a Sedan, all without having to worry about driving anywhere?

It's called Zipcar or your local equivalent.


Zipcar isn't prevalent in the US outside of major cities. But I've used it and it is similar to what I'm talking about, just imagine that but fully automated and run by fewer hipsters.


The definition of hipster has inverted if grey haired guys with MBAs are now hipsters.


> Zipcar isn't prevalent in the US outside of major cities.

Neither will any robotaxi or robocar system initially. I suppose some will view being run by nerds as an improvement over being run by hipsters.


And Google could probably provide the service for dirt cheap or even free by charging commercial venues per person delivered (at least if your business wants to be at the top of the list for "sushi.")


More likely is that hot meals will be delivered by a robotic transportation system. The same thing thats happened to a night out at the movies will happen to eating out at a restaurant. Except instead of a disc being delivered by snail mail, tiny robotic vehicles will text you when your meal arrives at the front door.


Or we could stop wanting to live out in the boonies and actually build things that people can walk to, then stop being so lazy.


I would prefer to be able to walk to everything I need. But unfortunately, that usually comes with a lot of other problems I'm not interested in.

The fact is that in a modern economy many things are shipped from business to business and from business to individuals. Laziness has nothing to do with it. Everything thats available in local businesses also has to come from somewhere.

Many things must go through many hands before they become available across the street. There's no reason a human being has to chauffeur things from place to place.


Or you'll watch a couple of ads during the trip ;)


Only if there's an option to pay for that not to happen.



Car-as-a-service. Nice.


This is already happening in the real world, driven by a number of companies which the author does not mention:

http://www.ultraglobalprt.com/ http://www.2getthere.eu/ http://www.vectusprt.com/

There is currently a system operating at Heathrow Airport; another at a campus in Abu Dahbi; and a third under construction at a national park in South Korea. Additional small systems are in the planning stages for a few more cities / institutions around the world.

Skimming the article (unfortunately I don't have time to read it in depth), it appears that the author has basically reinvented http://www.skytran.net/ -- a conceptual PRT system which has been kicking around for at least a decade and a half. Real-world PRT systems tend to be considerably more modest in their ambitions, following the "find a tiny niche" strategy of classic disruptive technologies (in the Christensen sense of the term), rather than trying to immediately become the be-all end-all of urban transport infrastructure.

Also, skimming the article, it appears that the author makes a number of quite silly mistakes -- curiously, the exact same mistakes that the Skytran people do -- concerning the dynamics and requirements of urban transport. For example, assuming a mean speed of 45 mph for existing transport is grossly wrong: it ranges from about 35 mph to well under 20 mph for more congested cities. (Here in London, it's 16mph -- a number which hasn't changed for over a century). This has some profound implications for how fast you need to go to provide a highly effective alternative, and correspondingly what your grid sizes, turning radii, etc. should be. It looks like the author gets all of this wrong, starting from a few bad assumptions.

Disclaimer: I used to work for Ultra PRT, and currently work for a large transport/planning consultancy, advising on PRT installations around the world.


For everyone who has not read it: Aaron is not proposing the future of ground-based transportation. This is an analysis why he scraps his plans for a magnet-levitation, personal transportation system and a call for new ideas.


To clarify, there is an urban density limit on this conclusion: "Time to get to a station (walking, or drive plus park) kills the effectiveness of most personal rapid transit and light-rail systems until you have a population density of 5000+ ppl/km2."

So for population densities of 5,000+ ppl/km2 this might work (emphasis on might).

Interestingly, urban areas of the developing world might qualify:

http://www.citymayors.com/statistics/largest-cities-density-...

The problem is that many of these cities might not maintain their high densities as their economies grow. My guess is that a lot of the high density is due to extended families living together. But maybe not, there are quite a few developed world cities on the list (e.g. London, Madrid, Seoul, Tokyo).

Unfortunately, I cannot vouch for the reliability of the statistics presented here, there just a result of a very quick google search. I've got to stop spending so much time on HN.


5000 people per square kilometer is only 20 people per acre, and any standard rowhouse neighborhood has 14 lots per acre, so this is only 1.4 people per house, a much lower density than you would get with large families or with multistory apartment buildings. A lot of cities that fail to meet this density are only because their legal limits also include a lot of essentially undeveloped land as well.


The overall trend worldwide is toward higher urban density, not less. This is more so in the developing countries - it's unlikely to swing away from this. As long as population is growing, the cities tend to grow (and become more dense) with them.


That is correct in the aggregate: people are moving from sparse rural areas to denser metropolitan areas. However, the urban density of metropolitan areas themselves is decreasing in the developed world. Most of the growth occurs in relatively sparse suburbs.


I agree.

But, also, in the detailed part of the proposal, he points out that with high densities (e.g. NY city) you need so many maglev cars to meet peak demand, that parking them off-peak is a significant problem.


Yes, but they could probably be automatically parked in tightly packed parking lots far out of town. As peak approaches, they could drive themselves back into town.

Because the customer doesn't require a specific car, these parking lots can be FIFO queues or FILO stacks and won't require maneuvering space.

Also, the cars could transition to a much cheaper, non-maglev parking system. This might even be done using a robot to lift and store the car into a slot in an otherwise "dead" grid. One expensive robot that can move in 2 dimensions and a lot of simple steel rails is a lot cheaper than heaps of maglev track.

Finally, the 333k car estimate was based on a subway where there is only one place that people are leaving from. There was an assumption that EVERY car must return EMPTY to the source of the trip afterwards to pick up the next passenger. This is not true, the percentage of returning cars is probably much lower (30%?) And even those cars could be useful for part of this trip.


How about bicycles? I live 4.2 miles from my NYC office and it takes me 45 minutes to walk/bus/walk. On bad days, it can be 90 minutes. The congestion in the NYC tunnels and in the bus station during rush hour is unbearable. Let me grab my bicycle and a place to store it during the day and I'll use it 10 months out of the year.


I believe NYC is implementing a bike-share program like the ones in Montreal, London, and other cities. Basically, you pay a subscription fee (or you can just pay as you go, of course) to get a bike from a docking station, ride it to another docking station closest to your destination, and push it into the station and forget about it.

The biggest problem, which does not at all make the system impractical, seems to be the availability of working bikes and open docks at the stations you choose. The city (Montreal) seems to have trucks that go around and redistribute bikes fairly often based off of the real-time data the stations give them. Still, there have been several situations where during peak hours there are favorite "pick-up" and "drop-off" points, meaning there are no bikes for you to pick up, and if you do get a bike, there is no space at the station where you want to drop it off. There is usually a bike or two that's broken down at each station, so it's important to put every bike through a few tests to avoid frustration.

For me, the times that it was the most useful was either to commute, supposing a bike was actually available, or to get home after a late night out after the metro has closed. I hate taxis and will only take one at last resort, it was awesome to just take a bike back home.

I overall liked it but it's difficult for me to justify the added cost, since I'm not about to get rid of my metro pass. I would probably end up saving money if I replaced my pass with bikes and packs of metro tickets if I really wanted to, but that would not work during the winter when the stations go away.


The lack of dedicated lanes was mentioned already. But this alone, while significant, is not the biggest problem with the bike.

Let's take Toronto. I could probably bike to work 9 km in an hour (half an hour if I had a dedicated lane - but I don't). However, in summer I sweat a lot and there are no showers at work. In other seasons - it is rain and snow that are the obstacle.


Brisbane has implemented a lot of bikeways, plus a shared-bike hire scheme and has a central parking facility, which includes secure parking, ironing and laundry service, locker rooms and showwers. So you can ride in, park your bike, get showered and changed and walk the rest of the way to work. It is quite popular and the overall scheme is working well.

http://www.brisbane.qld.gov.au/facilities-recreation/sports-...


I bought a Brompton folding bicycle in NYC. It's great. Very easy to bring on the subway, ferry or even a taxi.

The only downside is the small diameter of the wheels makes climbing a bit comedic.


I have a Strida folding bike for commuting in NYC by ferry and subway too. Love it.

Wheel diameter doesn't matter for climbing, though. Bigger wheels are more efficient on a flat surface by way of less rolling resistance; the bigger wheel creates a smoother tangent with the road surface, and contains more air so deforms less under its weight load. But when you're climbing, rolling resistance means almost nothing compared to the energy you need to supply to climb the well of gravitation potential.

The problem with climbing on a folding bike is frame rigidity. The geometry required by most folders (long single tubes connected by joints with necessary slop for folding) means that a fair bit of the energy you supply goes into stressing and flexing the frame rather than transmitting into the drive system. The traditional brazed diamond frame doesn't have that problem. To make an extreme metaphor, climbing on a folder is a bit like pushing a string, where the energy goes into deforming the nonrigid body instead of moving it.

If wheel diameter mattered for climbing, then either skateboards couldn't climb hills or they'd have bigger wheels for doing so.


The obvious problem seems to be that he wants a 200km/h speed which causes problems on corners and for getting vehicles into the traffic stream.

This is causing a doubling of his costs which wrecks the business model.

However even a 50 km/h speed ( remember no stopping at lights or for jams ) is going to be good-enough for many urban areas ( perhaps amining higher between suburbs ) so he can bring his cost back down.

The ULTra system ( http://en.wikipedia.org/wiki/ULTra_%28rapid_transit%29 ) currently has a maximum speed of just 40km/h although they are working on faster speeds and reduced spacing between cars.


Yes, I noticed that assumption too, and a few others(for example the assumption of "car parked outside home" - now you have to value either the cost of car ownership and parking, or the time cost for an on-demand fleet to reach the passenger) With a lower speed target the system may still offer benefits over roads and mass transit in terms of reliability/availability. The number of existing PRT companies continuing with this approach suggests it has some merit.

Maglev PRT still seems worth researching for intercity traffic though - the requirements for routing get a lot easier, and you still have benefits of speed and lightness.


The problem with a system like this is that it requires us to throw out the existing system and replace it. This is unlikely to happen.

I would assume that a more realistic system would to drastically expand our existing light rail, subway etc systems and fix the last mile issue with automated taxi cabs.

Automated cars have the advantage of using our existing road system without the existing issues of storage and accidents.

Combining them with an efficient mass transit "core" we could achieve all the above goals with minimal changes to our existing infrastructure.


I guess you didn't read the article:

""We live in a world designed around cars. Because world population has grown five-fold during the age of cars, we will be stuck with their legacy in roads and low-density metro configurations for at least the next century. This realization is a difficult one. I set out to start a company that could radically transform transportation. But neither the physics nor economics work out, and in fact will not work out until population density is much higher.

It is the ubiquity of roads, more than the greatness of cars that is difficult to defeat. And so, the future of transportation is, perhaps disappointingly, simply better cars. Our abstract criterion for the perfect transportation system is one that is fast, ubiquitous, has on-demand departure, and is quiet, private, and safe. The solution to all of these is a self-driving car.

It is clear that a maglev based personal rapid transit elevated track system should not be pursued as a business.""


Cars didn't invent the road, certainly not the city-based road, anyway.

Most of the worlds largest cities were designed and laid out long before a car was ever even dreamed of.

Roads, laneways and streets are a feature of every single ancient civilization. Mass transit is good at being mass transit, but personalised transportation (whether foot, bicycle, animal or vehicle) is always going to be with us.

Of course the future is cars for the majority of people, because the majority want personalised transport where mass transit is incapable of bridging the gap.


You make a good point here. Future transport system will have to leverage existing infrastructure to be successful. Multi-modal transport, like you are proposing, has are not easily solved. The time required to switch from one system of transportation to another requires hubs and introduces bottle necks and very advanced planning, perhaps even magical foresight, in regards to developing areas. A unified, personal transport system can scale more easily and has the benefits of privacy. That's why cars are relatively successful and haven't been replaced yet.

I'm unconvinced that collective transportation is the real solution to the problem, but it is the best intermediate solution we have right now. Downsizing cars, removing manual control, unifying speed, and adding distributed routing capabilities seems much more promising to me.


>and fix the last mile issue with automated taxi cabs

Why not bikes and walking? Consequently, this solution also fixes the following which automated taxis can't:

-pollution(bikes have much less total in mfg than cars) -maintenance(many bike shops exist and fixing bikes is comparatively easy) -parking(take it with you on the train, store in house/apartment) -cost(nice reliable used bike is under $1000) -familiarity/public acceptance(people are used to bikes) -security (take your bike with you and bikes have no software to break/get hacked) -human fitness (heart disease really sucks) -infrastructure (no batteries, gas, chargers, parking really required)


Bikes are not a useful solution to much of the populace due to medical conditions or climate. Looking out my window currently, a bike is pretty much impossible to use (ice, gusting winds). Never mind the additional facilities needed at the employer end (e.g. Showers).


Not having a shower hardly invalidates an entire transport system. Nor do I believe that much of the populace has a medical condition that makes it impossible to bike.

After a couple of years in Netherlands I strongly believe that to make the bike a success you obviously need a bike-suitable commute in terms of distance, but also, it needs to be safe. And that boils down to

- infrastructure that is designed for bikes and cars a like. Not some stupid painted lane as an after thought.

- Stringent traffic laws that protect the weaker traffic participant. In Holland for example, the burden of proof is for the more dangerous vehicle in a collision.

For this reason I am not a fan of bike-rental programs. I feel they are easy to implement (dump 20 bikes at train station) and get some political brownie points (see, we do bikes) yet change very little. Redesigning an intersection for safer passage is a whole different matter.

Inspiration? Have a look: http://vimeo.com/29401217

Yes, that is government promo, so here is a random busy intersection in a major city. Note, no helmets, no high vis gear, and all ages are represented. Also, no cars, no door-zone...

http://www.youtube.com/watch?v=n-AbPav5E5M


For what it's worth Utrecht has a high student population. Rather than weather, I suspect that flat terrain has the biggest positive effect on bicycle use, especially for commuting. On flat ground you don't have to work up a sweat.


Many cities (in the U.S. at least) have a metropolitan center that is almost completely flat. San Francisco, Pittsburgh, and Seattle are the most obvious exceptions, but as far as I can remember, almost all the other cities toward the top of this list (http://en.wikipedia.org/wiki/List_of_United_States_cities_by...) are really, really flat.


Weather is usually less problematic than you'd think for short rides in most temperate climate cities. It's only raining or snowing hard a small fraction of the time. Even with snow, once the roads are plowed you can bike with caution. Medical issues--I really think more people could bike if they had the courage; there are the elderly and the disabled, but your average 30 year old would do fine on a bike, even if overweight. Never mind the health benefits. I think what holds most people back are the safety issues with cars, particularly in the suburban sprawl where bike lanes are sparse.

~20 min bike commutes shouldn't get you too sweaty unless it's above 85 outside and humid. If it does, lower the pace and catch more of the breeze! For those that need to wear business attire, you'd have to stash your wardrobe at work. But I wouldn't think a shower is a requirement for most, just a bathroom to switch clothes.


Cars are successful because they work in all climes, are enclosed, and don't make people sweaty. Bikes will not work in a lot of places with snow because plowing doesn't really remove ice patches and winds can be brutal (40 - 60 mph gusts). The future replacement for cars will probably use the same infrastructure and be powered and enclosed.

As to the no need for showers, it seems a lot more people who think they don't need to shower actually do. I had a cube two rows down from a biker that believed that, but it wasn't so.


I think cars are successful for more complicated reasons than that, such as the physical and sociopolitical infrastructure invested in them, and advertising and culture. I can't speak for anywhere but the northeast US, but within every metropolitan center over here, biking would be a better form of transportation for at least half of city dwellers, 90% of the time--provided they all woke up and did it at once, regaining road-space from the taxis and the cars. Imagine New York, Toronto, or Boston with one full lane of every avenue bustling with bikes, the way you do in Amsterdam. There simply aren't enough ice patches and 40mph winds in any of those places to justify the level of car traffic. Also, anybody that currently rides the subway/bus/train or walks is already sweating and does not feel entitled to their own enclosed space.

The road to better health is paved with sweaty armpits. I for one would not mind a little workplace B.O. if it meant for happier, safer commutes and fewer billions spent treating the pandemic of heart disease and diabetes. But that's just me.


http://www.swedetrack.com/ is an older example of a similar idea, but I always think of JPODS http://www.intelligenttransportation.com/ when these ideas are suggested.

So this new idea is nothing new, just has a fancier site behind it. There are many examples available at http://faculty.washington.edu/jbs/itrans/itrans2.htm


> The problem with a system like this is that it requires us to throw out the existing system and replace it.

Right, because all horses were put down when trains were invented. And all rails were pulled up when cars were invented. And all roads were removed when, um, helicopters were invented, or something. Clearly any any new technology which isn't interoperable with the old requires the total abandonment of its predecessor. To ensure this, PRT stations will need to have some kind of access control mechanism which ensures that anybody who uses roads or cars is excluded from the system, and vice versa...

Sorry for the sarcasm, but this is an argument that I encounter far too frequently, and it's completely fallacious. Nowhere does it say that building new infrastructure requires the abandonment of the old.

Your second fallacy is the assumption that roads are necessarily "existing" or are in any way cheap.

First, in the next 40 years, the world's urban population will increase by 2-3 billion people. For the most part, the transport infrastructure they will use does not exist yet. Decisions on what that transport infrastructure should be can be based on current best practice rather than what is "existing".

Second, even in existing cities, roads wear out relatively quickly and are potentially more expensive to maintain / replace than PRT infrastructure. The balance of which is more cost-effective to (re-)implement is something that has to be looked at on a case-by-case basis, but is not nearly as straightforward as you suggest.

Third, roads are "cheap" only if you ignore the cost of the "rolling stock" (ie the cars people have to buy to use them), and also assume that the underlying land has no value. Note that this is a tremendous amount of land: between 45% - 55% of the surface area in most cities. PRT costs are generally given as inclusive of the rolling stock, and PRT infrastructure uses about 95% less land area per unit of capacity. In medium- to high-density areas, a full-cost accounting of this typically comes out wildly favourable to PRT.

Its two main drawbacks are that it does not handle crush loading caused by large demand fluxes (just like cars, but unlike trains), and that it is not cost-effective in low-density areas (just like trains, but unlike cars). Its natural niche is as an extension to light rail and subway systems (which can handle crush loads during peaks), serving medium-density areas which the mass transport systems could not economically serve on their own.


The reasoning and analysis is so silly I would question all of the thinking that went into this article:

“The real problem with PRT in dense urban areas is parking. During non-rush hour periods, what do you do with 333k vehicles?”

What a huge face-palm.

This refers to his statement about NY where he naively assumed the most sensible analysis was one that replaced the existing subway completely with PRT. - Then, magically, every person would go buy a car ( why? ) - All those people would need parking spots at the PRT stations that are within minutes walking distance - He designed a one-size-fits-all solution instead of recognizing that a combination of several specialized solutions is even possible.

You're not going to replace the ultimate freedom cars give you, nor the huge capacity the subway provides. PRT does something else - it provides a supplemental point-to-point transportation.

Also, the peak demand measurement is flawed because it is based on existing infrastructure. X cars go on a freeway / hour. Y people go on a subway / hour. But you are forced to use the 10 freeway because its the only infrastructure that provides for MANY routes [ santa monica - downtown ], [ culver city - hollywood ] and so on. Considering the "mesh" feature of PRT requires an analysis instead of starting and ending destinations - not the infrastructure those trips used!


Good lord, just making bicycling safe for everyone and there's your magic bullet.


Cost of asphalt is going up significantly! Even with electric cars, cost of oil may end up making track based systems more effective.Also, what is the maintenance cost of a road. Vs a track? And what about reclaiming all the land on the ground, and land used for parking? In some areas, that will more than pay for the system!


Given the upwards cost, and this sounds dumb, but I was kinda hoping for a revolution in bricks for roads. The brick laying machine out of Europe combine with some embedded RFID chip in each brick (perhaps with a different code for the road edge and turning lane bricks) might make for an interesting experiment.


I don't think PRT will win. The next transportation revolution will not require duplicating the infrastructure we already have.

I used to be enamored with PRT. It seems so logical.

And it might win if you designing a city from scratch and could layout everything to minimize the inconveniences inherent to a fixed track system.

But has it even been implemented in such a new community? No, usually people in even a new community have a strange need to go to other places. There's a system that already works for that. So they simply extend that system a little further and gain access to all of its advantages.

The next revolution in transportation will take advantage of this existing network.


They tried (and failed) in Masdar - UAE: http://singularityhub.com/2011/03/01/masdar-city-abandons-pu...

And I think you didn't read the article. It gets to exactly the same conclusion you did - or are you just trying to be witty? :)


Interesting. Hadn't read it, but the basic idea has been tried many times.


> The next revolution in transportation will take advantage of this existing network.

There is a simple concept that takes this assumption and adds some personal transit logic to this: busses with routes adjusted dynamically that just pick you up wherever you registered.

I first read about this idea in the famous Pattern book by Christopher Alexander written in 1977. It looks like existence of smartphones and availability of real-time traffic data and cheap computing power add some feasibility to this idea.


That should speed things down.


Unless there are tracks, I find it hard building an automatic PRT on current network (roads).


No worries, PRT will have nothing to do with it.


i remember seeing an example simulation 6 months ago out of europe where they were using high speed rail with feeder cars that would pull up alongside the main fast train to let people on/off, without slowing down the main train. this was thought up to speed train travel as the acceleration/deceleration of maglev trains contribute to their energy and time delays.


I have to confess, that links and discussion like this are my secret number one reason to visit HN regularly.

By reading the comments on swiftprt.com I also found the interesting project of electric airplane takeoff http://electrictakeoff.com/

Is there an online community that discusses such questions more frequently?


I see this idea as fundamentally flawed in that it's trying to do 2-person cars. After I read that, none of the ensuing calculations mattered at all. We need to work around the train schedules, not try to work them around our schedules. Look at downtown SF. Mass transit there is AMAZING. Muni stations are every few /blocks/.

Also, why choose below-the-rail? Requires stronger towers, can't turn as fast as existing rail, etc. This was a silly decision IMO. I think these guys need to work with roller coaster engineers if they can only do /10kmph/ around curves.

Yet another still-born mass transit idea. Can we please just get the Cali high-speed rail done already to prove to the rest of USA something that other countries know already? High speed rail works great and can indeed "work" economically.


In fact there are people, who are trying to implement similar system: http://www.mist-er.com/ It is not MagLev, but the basic idea is same.


It's seems like the "getting to the station takes ten minutes" problem is easily solved with things like the Segway, if people could be expected to actually ride them.


Since I sometimes commute by Caltrain, I have been very interested in this "last mile or two" transportation problem.

A remarkable number of engineer/entrepreneurs have sprung up attempting to offer devices that solve it. Here are some highlights of what I've found:

Segway: easy to ride and reasonably fast, but expensive, and worse, much too heavy (100 lb) to pick up and take on a train.

YikeBike folding electric bicycle: looks not too hard to ride; a little slow, perhaps, at 15 mph. A technological marvel (anti-lock brakes!) but correspondingly expensive ($2000 for the 31 lb model, $3800 for the 24 lb carbon fiber model).

Conscious Commuter folding electric bicycle: this is a very nice-looking design whose development was recently funded on Kickstarter (http://www.kickstarter.com/projects/1585753369/folding-elect...). No specs yet, but looks extremely promising.

Trikke EV: a very creative design. Looks fun to ride, but a little heavy for this purpose (38 - 46 lb depending on model) and not particularly fast (13 - 16 mph).

Metroboard electric skateboard: reasonably fast (20 mph) and extremely light (~20 lbs depending on model). I have one of these and it's an impressive piece of engineering and fun to ride, but it does require substantial athleticism and, uh, a certain risk tolerance. Not a mass market product.

If those aren't exotic enough for you, a number of people are working on self-balancing electric unicycles (!!).


If we're talking about a "last mile or two" what's wrong with a conventional bicycle? These other things seem to be needlessly expensive and complex solutions to that problem.

The big problem with all of these though is they are all unpleasant in inclement weather and cold temperatures.


Conventional bicycles are bulkier than these other solutions, making them harder to carry onto whatever mass transit one is using. On Caltrain, for example, bicycles are restricted to a special car at one end of the train. On other systems like BART, bicycles aren't even allowed on many trains.

The other problem with conventional bicycles is that it's hard to go very far without getting sweaty -- depending on the weather, of course, and one's patience for riding slowly. It's nice to have power assist.

Folding bicycles can be compact enough to carry on any mass transit conveyance. The Metroboard is certainly quite compact and portable. Not sure about the Trikke.

You're right that weather can be a problem.


I'd get a cheapo used bike and lock it at the station. Bike racks/poles are everywhere; personally, I think people carrying their Inspector Gadget $2000 foldabikes on the train are overestimating the utility of taking the same bike everywhere. As for getting sweaty, this is just the last mile we're talking about--if you get worked up on a 10 minute bike ride it's time for more exercise!


I think weather can be more of a perceived problem than an actual one, sometimes.

I ride a bike here in northern England. For two short rides of about 15-20 minutes each way, the chances of being rained on are pretty small; maybe ten times in a year? If you had a folding bike, then ten taxi rides on wet days might be a worthwhile yearly penalty.


In North Dakota, weather is not a perceived problem. Cars work everywhere, and it is likely that he replacement needs to do the same.


"last mile or two" transportation problem.

Non-existing problem. Walk. For two miles, use a cheap bike. Done.


You can't get your bike to the last two miles, easily, on public transportation. That's the point.


Then leave a bike at the last two miles, go to any railway station in the UK and you will see thousands of bikes left for the last part of the journey.


Exactly. And a lot of cities started implementing bike rental systems.


I want to see someone build a cheap (several thousand dollars) version of an enclosed motorcycle like this: http://green.autoblog.com/2011/09/19/lit-motors-c1-enclosed-...

And then a self-driving model :)


Very cool!!

Reminds me of the Gyro-X, a gyroscopic car someone built in 1967. I still remember reading about how the car could be made to stay perfectly vertical in turns, or even lean outward.


I think that problem is better solved socially than through engineering. Walking two times ten minutes every day will not harm anybody who is fit enough to travel by public transport. On the contrary, it would be a contribution to the fight against obesity. So, we should strife to promote this as a _free_ way to work on one's health.

Yes, the climate may be harsh at times, but that Segway will have trouble in a foot of snow or in a monsoon, too.


Aaron, why don't you work on self-driving cars?




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