On ultralight vehicles vs. large mass transit vehicles

One of the questions raised by the numbers which show that U.S. transit does not compete well on energy-efficiency was how transit can fare so poorly. Our intuition, as well as what we are taught, makes us feel that a shared vehicle must be more efficient than a private vehicle. And indeed a well-shared vehicle certainly is better than a solo driver in one of todays oversized cars and light trucks.

But this is a consequence of many factors, and surprisingly, shared transportation is not an inherent winner. Let's consider why.

We have tended to build our transit on large, heavy vehicles. This is necessary to have large capacities at rush hour, and to use fewer drivers. But a transit system must serve the public at all times if it is to be effectively. If you ride the transit, you need to know you can get back, and at other than rush hour, without a hugely long wait. The right answer would be to use big vehicles at rush hour and small ones in the off-peak hours, but no transit agency is willing to pay for multiple sets of vehicles. The right answer is to use half-size vehicles twice as often, but again, no agency wants to pay for this or to double the number of drivers. It's not a cost-effective use of capital or the operating budget, they judge.


The urban vehicle of the future, as I predict it, is a small, one-person vehicle which resembles a modern electric tricycle with fiberglass shell. It will be fancier than that, with nicer seat, better suspension and other amenities, but chances are it only has to weigh very little. Quite possibly it will weigh less than the passenger -- 100 to 200lbs.

Transit vehicles weigh a lot. A city bus comes in around 30,000 lbs. At its average load of 9 passengers, that's over 3,000lbs of bus per passenger. Even full-up with 60 people (standing room) it's 500lbs per passenger -- better than a modern car with its average of 1.5 people, but still much worse than the ultralight.
Light rail vehicles are even worse. They aren't light at all, weighing around 150,000lbs per car with 72 seats or over 200 people standing at full load. That means with everybody seated we're moving 2000lbs per person (worse than the average car) and fully loaded around 600lbs of vehicle per person. The DoE says the average train carries 23 people -- that's 6,500lbs of vehicle per person, more than even light trucks and SUVs.

As most of the weight in vehicles comes from metal, the energy cost of manufacture of the vehicles is closely related to the weight. For the ultralight single person vehicles, most of the weight will actually be batteries, and only the frame will be metal.

Stop and Start

All this weight is even more expensive because transit vehicles have to start and stop all the time. On electric lines, they can put some of that stopping energy back into the grid. Hybrid cars put some of their stopping energy back into batteries. Ordinary diesel buses don't do any of this, and even with the regeneration, the stopping and starting is highly wasteful -- but unavoidable for shared transit. Cars stop and start at traffic lights and stop signs, of course, but far less often. And the automated cars of the future, which will plan their trip and speed to glide along perfectly with the lights may not have to stop much at all -- and they'll do it with electric regeneration, slowly.


Moving weight is only one use of energy, of course. There is also air-drag and rolling resistance. The drag coefficient of trains (1.8) and buses (around 1) is much worse than that of cars (.26 for a Prius) or low-slung streamlined vehicles (less than .1). However, here, the sharing is a win. 9 people on a bus do better than 2 in a car or 1 in an ultralight, but not much better. 23 people on a train do even better. Long intercity trains do even better here. Indeed it is long intercity trains that are the most efficient vehicle we currently use, because at high speeds, air drag is the largest drain of energy, and long trains can have the least drag per person compared to short vehicles. Because loss to drag goes up with the square of velocity, jet aircraft, even though they are highly aerodynamic, lose out because they go so quickly. (Of course that speed is not without its upsides.)

Commuter trains are our next best bet. They don't go as fast, and they usually make only limited stops, and they usually run only at rush-hour so they have better load factors. Once they start having to run at all hours, they start to lose their gains.

Robotic single-passenger vehicles could also form virtual trains on the roads, following closely to gain much of the drag benefits of rail-based trains.

Rolling resistance also is not so bad for the large vehicles. Steel on steel, as found in rail, is 10x better than rubber on concrete, though light rail is not nearly as good due to both dirt and regular turns. However, rolling resistance also goes up with the weight, so a street car with much more weight per passenger loses the benefit it gets from being on rails.

Engine losses

The biggest loss of energy in transportation is engine loss -- energy wasted converting from the fuel source (gasoline, diesel, coal) to forward motion. Electric ultralights will do slightly worse than electric trains due to the use of batteries instead of overhead wires, but this difference is modest. Fuel burning buses and cars suffer more.

Trip Length

Next, transit vehicles run on transit lines. If your trip is not precisely along such lines, your trip is longer. Most transit systems are designed to move people to and from transit hubs, particularly a downtown. Yet the majority of trips in a typical city are not to and from downtown. Such trips require the use of multiple transit lines and often a lot more distance. In some cases, transit lines with private right-of-way may offer a shorter trip, but this is rare. The private vehicle trip is point to point.

However, it is true that if you want to reduce the number of private vehicles around by sharing them, there is some need for empty vehicle moves, which reduce the efficiency. However, if the vehicles are ultralights which weigh less than the passengers, the energy for these vehicle moves can be quite small.

It should be noted that studies show that transit users tend to take much shorter trips than car users. This fact has a complex explanation which is the subject of much debate. Some argue that the "transit lifestyle" encourages people to choose destinations for work, shopping and social life which are within a short transit trip, and that if everybody did it, we would all travel less and save energy. That cars have enabled us to live further from things and thus make us travel more. Others argue that there is a selection bias -- those who live close to downtown can take transit, those who don't can't. Both would agree that the slower speeds of transit (outside of dedicated ROW commuter trains which can outspeed cars) make it difficult to take long trips, but disagree on whether that's a feature or a problem.

Computer coordinated shared vehicles

Shared vehicles can be more efficient with computer coordinated carpooling, so that computers notice when multiple people want to take exactly the same route (full shared) or segments of the same route (Jitney) at almost exactly the same time. While this is more efficient, passengers will still pay a fair bit more for very low wait time compared to the added wait of shared or jitney service. At rush hour, finding people with common routes will be much easier. Solo and 2 person (inline) vehicles can be only 3' wide, however, which allows them to go 2 to a lane and possibly use cheap elevated right-of-way, while larger vehicles will be full-sized and constrained to existing roads.

Shared transit can be the most efficient system at rush hour, if cities are willing to devote vehicles and track/ROW to it, when the vehicles will not be used the rest of the day. Computerized operation could reduce the issue of having to hire drivers only for rush-hour. It's also possible that dedicated ROW at rush-hour could be released to computerized personal vehicles during the rest of the day, or even in between transit vehicles, which are usually spaced several minutes apart. In this case, the vehicles would need systems that can assure they clear the ROW in advance of any transit vehicle, which seems doable. Indeed it could be arranged that no vehicle would enter the ROW unless it had a travel plan which assured it would never impede a transit vehicle, with some slop included.


This analysis makes it a little more clear how 80 small single person vehicles can be more efficient than even a well packed bus or street car with 80 people on it. The 80 vehicles weigh less and stop less, though they have more drag and rolling resistance. The 80 vehicles cost less energy to manufacture, but if they are used only by their owners there will be a lot more of them. If they are shared (ie. they are taxis rather than privately owned) they will have a lower energy of manufacture, but a modest loss (worst case about 50%) for empty-vehicle moves.

Once you start comparing the individual vehicles to the average loads for transit vehicles, the energy efficiency victory of the private vehicles is much easier to establish. This is particularly true if the small vehicles are electric and make use of regenerative breaking, and clever navigation to avoid stopping and starting, as well as any need for sudden starts or stops. Based on DoE figures for transit ranging from 1,200 to 7,500 BTUs/passenger mile (3,500 average), and the figure of 300 BTUs/passenger mile for existing simple ultralight designs, the personal vehicles are 5x to 10x greener.

Even "light" vehicles (such as the Tesla, Tango and many others) which meet highway safety standards still do quite well at 1,200 to 1,500 btus/mile and 800 to 1,200 btus/passenger-mile when shared, if they can be shared. They still beat U.S. transit, though not Asian transit.


If you can manage to find, say, ten people with the same origin and destination who want to leave within, say, five minutes of each other, that's still an improvement over sending them each along in their own vehicle. This, of course, is more likely to be feasible in urban environments.

Yes, I meant to write a bit about Jitney style vehicles and pure shared same-destination vehicles as you describe. Proper computerized scheduling can make them the most efficient of all. Though the question becomes, how much cheaper are they? People will spend more to not wait 5 minutes. I could easily see people paying $2 for a vehicle they don't wait for compared to $1 for a shared vehicle, and it's hard to get twice as efficient with the shared vehicle. (Of course they would also be happy to take the shared vehicle if it can come first because of a shortage of solo vehicles.)

Realize as well that solo vehicles, just 4' wide, and go 2 to a lane, while shared vehicles for more than 2-3 people (which might go inline) will take a whole lane.


I have been dreaming about this kind of personal transportation for decades now. What I can't seem to get past though is *how* it could ever be implemented.

A personal lightweight vehicle would initially have to be on a private road, but their requirement to go from endpoint to endpoint precludes that.

Or do I need to think about it more?


Well, the initial impetus for considering a world of ultralight single person vehicles is robocars. However, it's certainly possible to consider a world of human driven ultralights combined with safety systems built from the precursors of robocar technology. Such safety systems should be able to reduce accident rates enough that people could feel safe driving ultralights. Today, riding a bicycle (which is beyond ultralight) has its risks but it is still workable. Motorcycles are the most risky vehicles, but this could be improved a lot.

The ultralight vehicle I speak about is probably a tricycle or computer-stabilized 2-wheel vehicle which is able to also stop and be stable while slow (either with computerized track stand or extended stability wheels.) It probably is not able to go more than about 35mph, being meant only for short urban trips, not highway speeds. Of course, there is no reason you can't build ultralights for highway speeds, though people might not find them safe enough yet.

We could encourage ultralights by giving them their own lanes (where they can go 2 to a lane) designed for safety. This could include cheap 5' wide elevated pathways - cheap because they only hold lightweight and thin vehicles -- which are also safer, with no risk from heavy vehicles. Ultralights themselves would present very limited danger to heavy cars. Their danger would be to their occupants, and to pedestrians.

Brad, It is a great delight to find anybody who is thinking about duplicate roads, exclusively for the use of lightweight vehicles (DELVR)---I have been looking for sometime and this is the first I have found.
Here are the things that I think DELVR deliver. First, safety for the users of lightweight vehicles, especially if these roads are COVERED, dry roads are great for motor bikes,or any narrow wheeled vehicle (cost is trivial). Second, reduce congestion and improve ordinary roads---we all benefit if we use roads which are nearly always at full capacity right now--- this way we can get average speed of 50mph for commuters instead of the present 25mph. Third, low embedded energy if built beside or above existing roads---reflected in low cost per. mile compare $500 million for tunnels, $50 million for inner city motorways, with less than $10 million, and often much less, for lightweight vehicle roads, which need minimum foundations, cuttings, drainage, or structural paving and low maintenance costs when covered. Fourth, we all replace our vehicles every ten years, so we can reduce greenhouse gas emissions really quickly---and over 100mpg is very attainable for lightweight vehicles, plus ordinary vehicles use 30% less on highway cycle.
And then finally, we can get the benefits of every flyover at traffic lights, every bottleneck removed, etc, and it will still be useful for robocars or electrics when and if they come.

The idea is sound, the problem is making the transition. You've skipped around this a bit, but you can't put ultralight vehicles on the same roads as current motor vehicles controlled by humans. Same problem as bicycles face and the one that's driving the arms race on US roads right now - in a collision the lighter vehicle loses.

So the question is how to get ultralights into the system. Do we build a whole new road network? Do we let them use existing bicycle infrastructure (where the safety problem is reversed, an ultralight doing 20m/s hitting a cyclist is going to cause problems)? Do we ban ultraheavy motor vehicles from some suburban roads (an existing strategy)?

I think the most likely approach will be through gated communities, where we're already seeing golf buggies used as slow transit. It might be possible to mix these things up with bicycles if that was combined with a serious bike-lane building program. The sort of "any road with more than one lane in a given direction shall have the outer lane replaced by two ULV lanes" wholesale conversion. The trick would be to legalise power assisted velomobiles in some cunning way such that they became more attractive to manufacturers. The power limits in the US are already pretty high, so building a ULV and slapping decorative pedals on it might be the way to start.

So, what are the legislative hurdles to selling an ULV as a bicycle?

Well, I first wrote about this as a robocar transition. Along the path to robocars, all vehicles will be getting incremental new safety technologies that make them harder and harder to crash, even with a human behind the wheel. One way to such a technology would be to demand that the heavier the vehicle, the more anti-crash safety systems it has. We already have light vehicles on the road, of course -- bicycles and motorcycles. We also have light vehicles (things like SMARTs) which have roll cages, seat belts, air bags and crumple zones.

Our ultralights can have air bags and seat belts, though they won't have too much of a crumple zone if faced with an SUV.

I don't actually believe that being in too light a vehicle is that much of a contributor to vehicle deaths, but I doubt we'll break people of that intuition. The classic example is the SUV. People think they are safer in the behemoth, it turns out they are so topheavy that they are sometimes less safe.

If we were starting from scratch we would probably have two drivers licences -- one for light vehicles and another for heavy ones (ie. modern SUV/miniman.) Just as we have yet another class for real heavy trucks. A single DUI, even at a lower alcohol level might lose your heavy vehicle licence. The heavy vehicles could be kept to a lower speed limit on city streets, especially in the evenings during "drinking hours" without a special licence.

However, I agree these things are not politically palatable quite yet.

Note that we don't have to go ultralight to beat transit in the USA. A small electric like the Tesla, which still meets the safety requirements, still beats transit in energy efficiency. Ultralights are needed to beat Asian efficiency numbers.

So you're looking at this as a fix over the next hundred years rather than then next ten, then? Over the next twenty years or so introduce more lightweight cars and hope that the relative cost of electric cars drops so that by the time current SUVs drop off the roads people willingly buy the electric ones. Then after that transition hope that asian countries are using ULVs in enough numbers that they overcome the US NIH problem. Once they're legalised in the US they will slowly grow in numbers until they become part of the overall transport solution. No active support required.

Incremental safety changes on the way to robocars also push that idea out a long way. I'd say at least 20 years, even assuming an optimistic five year generation length for cars. Stuff that's in high end luxury cars today will typically take more than ten years to appear at all in cheap cars, then you have to wait for the existing stock of cheap cars to leave the road. Add in the time between now and a robo-Mercedes ... I'd say more than ten years, and you're looking at 30-50 years just to get to the point where ULVs can share the road.

I very much doubt that robocars will appear in much of asia first. It's vaguely possible that somewhere like Tokyo or Seoul will support them, but they have the same transition problems as the US does (existing cars and roads). If you look at countries like India and China they're moving more towards unsafe small electric cars to go with their unsafe small infernal combustion engine cars. Either way, they're fossil fuelled.

Which is why I think selling them as power assisted bicycles is the way to go. It avoids the whole problem of regulatory stupidity that has stopped other lightweight vehilces being permitted. Sure, once they start appearing in numbers there will be a legislative backlash, but my hope is that we'd see an innovation race with local wins due to the US federal system. Which could mean that a workable system shows up somewhere and slowly spreads... the way gay marriage is, for instance.

How long is not something we can say yet. But there isn't so much a transition, I think. The first robocar on the road drives with all the other cars human driven. In fact, this car is already on the road to some degree, in that there is a robocar developer who lets his robocar drive him around, though he still carefully watches it and is ready to take the controls if there is a problem. There will be more of these as time goes on, unless it is overtly banned, and even then it will happen.

The transition comes when people judge that the other heavy cars on the road are not so scary as to make you unwilling to ride an ultralight. Obviously some number of people are willing to do this today in their bicycles, motorcycles, NEVs and super-small cars. They do it with some risk, but not that great a one.

Today, a vendor can't sell a car that doesn't meet various crash and safety tests. By this argument, if you tried to introduce bicycles today you probably would not be able to use them on the road, they are clearly unsafe in a collision with any car (or wall for that matter.) Since the bicycle came first, we don't think of that as a fault of the bicycle, nor should we.

Travel to other countries, such as India, and most of the people are on the road in what we would consider ultralights. Bicycles, 3-wheeled mini-trucks, scooters and the like -- on many roads what we call cars are rare, and they don't go very fast because they are too big.

But we don't need robocar safety to have a safe, light vehicle. Even the lightest vehicle can have crash avoidance systems, air bags, seat belts and a roll cage. Indeed, because it is light (and not going above 40mph) the crumple bars in the chassis do not need to be nearly so heavy to allow the vehicle to hit a wall (or other vehicle) with passenger survival.

The issue is being hit by a fast moving heavy vehicle. Small cars already can't handle that well. Is the answer to make every other vehicle on the road heavy too? Or to regulate the heavy vehicles to make them safer. Eventually requiring advanced safety systems, and as I suggest, a higher class of licence, no DUIs etc. to drive a heavy vehicle. Heavy vehicles are both a risk to others on the road, and of course energy wasters too.

The robocar safety systems are hard to predict, but they are not 100 years away. I think a decade is more reasonable for their availability. A GM executive (who was on the BOSS team) just made a prediction of full robocars in 10 years. That's a bit optimistic, but 100 is too far the other way.

These are very interesting figures and ideas, but tend to require completely revamping entire systems and do not address the central problem: we drive too much, and buy things in an ad-hoc way based on price, which leads to traveling to big-box centres and extended rounds of shopping and price comparison. Your suggestions- robot delivery vehicles and tiny individual vehicles- are impractical with today's technology and infrastructure(as you have noted). I think robotic control will be an afterthought to traffic-planning and management systems (systems that allow you to take a route that requires minimal start and stop cycles but that still requires the driver to control the vehicle), and will happen only after such systems have been in place for decades. I believe we should be changing the way we use the infrastructure (in cities) and changing the infrastructure gradually in suburban and rural areas. Even if the horizon for robocars were only 30 years from a technology and regulatory standpoint, I believe that economic arguments against them will cause them to be something other than we can imagine today. Science fiction writers in the '30's didn't predict atm's, they dreamed of all-purpose bipedal servants. Looming economic crises in the USA and the global energy crisis will cause massive cultural shifts that will make these concepts irrelevant. If you do your international business by video phone, it's illegal to own a summer cottage, and you can't afford to take frequent road trips to visit relatives 200 miles away, the concept of a robot car (or a private car in general) has much less appeal.
Your transit energy efficiency figures seem reasonable to me. Your conclusion does not. I live in Toronto; there is a streetcar line in front of my house. These things are TRAINS. Instead of two different vehicles, you could add a second passenger car to the engine for peak service times (this would require the addition of sidings on routes, probably at one of the ends).
The tiny vehicle argument goes against several embedded North American cultural norms: they will only be adopted after an oil collapse. (And I believe that will be the scenario: once there are fewer cars and no non-commercial large vehicles, it will be possible to do this).
I think we will see business models that compete with the private car before we see robocars or individual high-efficiency vehicles. I drive twice a week to buy groceries. Imagine a system where you could place an order for 2 days groceries at 9am from a full-service supermarket chain and pick them up from a corner outlet 3 blocks from your home that afternoon (or have your 10 year old son do it)? Such a system would eliminate at least one level of storage and transport, and probably two. It would allow smaller refrigerators in homes and eliminate some of the most energy wasteful store refrigeration and freezing systems (open display cases). This type of system would eliminate several car trips and encourage walking. Another example is Toyota's Japanese sales model: the salesman comes to your home. If this system were applied to other consumer products, there would be a further lessening of the energy-wasting big-box culture. Yes, these two ideas do not change the whole system, and are not immediately competitive with a low cost energy culture and embedded private car ownership. But they can be instituted on a time line far shorter than high-efficiency vehicles, be tested on a small scale and on an incremental basis, and be tailored to local conditions. They have far lower up-front risk and no legal impediments. The technology already exists. This will happen first, and change the environment of automobile development.

All of these things are big changes. Outlawing owning a cottage? Not only is this not going to happen, we don't want it to happen, we would much rather find more efficient ways to get to the cottage. I believe the only way to make things work is to offer the people transportation that is both cheaper and superior (and also greener) and they don't even care about the last one except when it helps cheaper.

That's why the ultralight has appeal, if you convince people it's safe. Certainly better than riding transit, and if it's cheaper and greener it can be a huge win. Not as comfy as a minivan, so there is a hurdle.

Most of the world uses tiny vehicles. In Canada we don't. But at the same time a lot of people in Toronto and New York abstain from cars all or much of the time -- if you don't count taxis. It shows that different modes of thinking are possible in our society.

I predict it is possible, though not of course assured, for robocars to blindside all transportation planning, because technically they should appear in 10-15 years. Whether society will accept them that soon is another issue.

As for grocery delivery, that has been tried and is still offered but for now is not too popular. People seem to want to hand-pick their food. However, for ordinary manufactured goods, especially things like books, electronics etc. we're seeing online take over from retail even without the benefit of instant delivery.

Hi Brad and all:
Since I first wrote, I have done some extra calculations and got extra ideas. Basically, DUPLICATE roads for lightweight vehicles is looking better and better, but acceptance is looking worse and worse.
Cost of duplicate roads (four lanes per. side;two for light cars, one for small motorbikes, and one for pushbikes) would be about 10% of existing---say $5 million per. mile. Compare that with a four lane tunnel, $500 million per. mile; or a normal freeway, $50 million per. mile---and this benefits everybody, since the congestion is reduced on the heavy vehicle roads.
The big attraction from a greenhouse gas emissions standpoint, is low embedded (embodied) energy; in the road and in the vehicle, and the ability to implement quickly, since the life of vehicles is only about ten years, this can be done by 2020.
On congested roads with traffic control lights, lightweight overpasses are even more attractive, and possible.
And, when and if we go to electric cars---which currently have very high embedded energy---these roads will really help the transition.

Ultralight vehicles are a good idea. If you look at Toronto as an example, it's already starting to happen, though, of course, on a small scale. Ontario recently (a couple of years ago) allowed electric bicycles (many of which are not really bicycles, but essentially electric scooters), and people are buying them. Same for Vespas and other small scooters. In Europe and Asia, of course, scooters are immensely popular. Even without the protection of seatbelts and airbags, and without the stability or a three- or four-wheeled machine, these small vehicles are sharing the roads with cars, and there is demand for them. Add these extra safety features, and even more people would find these vehicles attractive and feasible.

Building a separate road system is an absolute impossibility, in my view. For one thing, there isn't any space in urban communities for extra roads. Even installing separate lanes is problematic: as anyone who dealt with the subject of bicycle lanes knows, separated lanes create problems at intersections, and urban roads have lots and lots of intersections (including driveways etc.) I have a feeling that lighter vehicles can start appearing on our existing road network and slowly gaining greater and greater share of trips. This will happen quite naturally as oil supplies will start dwindling noticeably and people will look to migrate to more efficient vehicles. People will also probably make fewer trips and go shorter distances: the nature of the communities will likely change to make most amenities more conveniently accessible by foot or a slower lighter vehicle.

There is still nothing wrong with having mass transit, but I agree that it will never be the only transportation method: it's just one of the ways to get around, very efficient and convenient in some scenarios, but very cumbersome and problematic in others.

I live in Orlando and they keep talking about putting in a light rail system, which I suspect will not work very well. I wonder if it would work better to take the right of way proposed for the light rail and convert it into a dedicated ULV road? Set a maximum speed of 40MPH and limit it to electric scooters and such. I was also thinking of making it one way and have it run downtown in the morning and out in the afternoon. I would think it would be able to accommodate at least three lanes of ULVs one-way.

Do you think if Orlando built such a road, people would buy ULVs just so they could use it? Should we also allow unpowered bicycles to use the road?

These might make a worthwhile experiment. You can always add light rail tracks to such a road if it's not elevated. One of the main advantages people see to ULV roads is you can make them elevated at low cost because they don't need to bear much weight. The main issue is people not wanting an elevated roadway in their view.

Depending on what other traffic is like people might very much like such a road and buy vehicles for it. Single person lower-speed electric vehicles with range for a commute can be made quite cheap. However, at 40mph the crash risk is higher and this adds a lot to the cost of the vehicle to meet today's crash standards. A top speed of 25mph, I believe, allows a much simpler vehicle but that won't compete with any highway driving. Most transit on streets only accomplishes around 10mph so it can readily compete with that, but that speed limit may be too much for people with a long trip to or from the dedicated ROW.

Brad, I did some more checking and the right of way they are using is shared with CSX, so a ULV isn't an option. I actually looked at the projections of the people proposing this and and they project a cost of building the system at $616 million and 7,400 passengers per day. Even on their own projections, that comes out to $83,000 per passenger. It seems to me that could put the money in the bank and buy the riders a new hybrid every 10 years.

It seems to me, that if the point is to reduce congestion on the roads, that it would be better if they set up incentives for large companies to have their own bus system like Google.
Disney and Universal alone have 70,000 employees.

The Google buses have Wi-fi, so the employees can surf the web, sleep or even work during their commutes.

I read an article in the Sentinel that describes the price tag for the system at 1.2 billion, not 600 million.


Also 7,400 was passenger-trips. That would mean 3,700 people per day if you assume most people ride both ways. That works out to $324,000 per person.

I was watching Demolition Man the other night and was curious about the car Wesley Snipes was driving. I googled it and it turned out to be a real prototype car that GM built in the eighties called the Lean Machine. They claim 200mpg for the car, which I find difficult to believe.

The car Sandra Bullock was driving was another prototype called the Ultralite. It was a 4 passenger car that could produce 100mpg at 50mph.

It makes you wonder how things would have turned out if GM had developed production cars from these designs.

To a small extent, this is happening a bit in Portland, Oregon and seems to be catching on fast (although Portland is full of people who are all about energy efficiency). Various companies are beginning to utilize this idea by creating small electric, enclosed bikes meant not for use on freeways, but instead for use downtown in urban areas. I've noticed that these often take the place of urban car driving downtown, particularly for those that live in condos downtown anyway.

In addition they often utilize portable solar chargers to power small electronics and the battery of the bike while running and stationary. Recent stories in Portland newspapers (such as this one, in addition to solarpowerchargers.org) confirm this fact. This helps curb the overall energy usage, but often falls a bit short since Portland isn't always the sunniest of places. A bit far from the ideal situations you have mentioned before but it's still exciting to see that people are at least open to making changes to their routine based on the idea of energy efficiency.

I would be curious for a response from "Nick Jacobs" but this comment surprises me. The links in it (one of which I removed even though all links use nofollow so they are of no value in SEO) had only minimal bearing on the comment, and I have a strong suspicion that this was just an excuse to put a link in to the solar power charger company. Yet at the same time the comment was fairly on-topic. I get spam every day where somebody posts a comment that tries to be on topic and throws in a meaningless link. Normally they are very easy to spot, they are very badly done. I have never seen one this good before. Am I wrong? Solar charging for vehicles is pointless and an anti-green idea, but I don't mind if people want to argue about that.

Still waiting for you to clear my last post with a link to a PC Pro article about "the end of sci-fi".

Probably better to keep stuff for my own blog. It's more for me and I can quit reading yours.

Yes, I agree, put the stuff on your own blog. I get a lot of spam. Your post was written with broken HTML so it went into the approval queue, and I only look at that every few days, if that. Sadly most postings with links are fake postings these days.

Hey brad, rather than spamming great blogs like yours, I always try and provide legitimate, on-topic and meaningful responses in order to earn the link in the response. I wasn't trying to hide the link, but was trying to provide a legitimate response and add to the discussion. My site is on-topic and relevant, and I hoped that talking about green initiatives where I live would have earned the link, but I realize that I fell short. I believe that blogging does not happen in a vacuum and requires a bit of marking, and commenting on great blogs like yours is one way to market a new site, regardless of any search engine benefit (no-follow links do help, and moreover, by linking out to trusted sites without the no-follow attribute, you will actually help your website become more trusted in return...). I like your blog, and have done search engine marketing professionally for years. If it makes up for it, feel free to email me any questions you have about search engine marketing and I will answer them for free.

Brad, you said "Even full-up with 60 people (standing room) it’s 500lbs per passenger — better than a modern car with its average of 1.5 people".
Why do you compare a 'full-up' 60-pax apple to an 'average' 1.5-pax orange? That's a stunt transit uses to justify its existence. Why not take it one step further and factor in Robocar on its way to pick up its 1.5 pax (i.e. "O")?

It starts out with the comparison of average bus (with 9) to average car (with 1.5) and the point of the full bus comparison is to show how heavy the bus is. The empty car going to pick up a passenger does indeed reduce the average passenger load in it. New York taxis are only occupied 62% of the time -- but they spend a lot of time just cruising looking for fares. Other models predict robocars running empty only about 10% of the time. However, by matching the car to the number of passengers, their overall efficiency will be much higher.

Sitting in parked 8-lane traffic looking at the rows of street lights I invented Ultralight rail before I learned that others did before me. By having a buried power strip and no bumps the cost per mile gets very low. By having computer control, even running at 300 mph the distance between vehicles could be very small. With only yes-no switching there would be little need for complex routing as it would be very like computer packets on the internet, and speeds could be maintained at maximum for any stretch.

By keeping everything at the minimum weight the structure could cost a tenth per mile Of normal rail so ten times as many miles and much less than roads. An artery and capillary system would get you on or off only at capillaries so not disturb traffic, and as a raised system not disturb right-of-ways, staying above except at capillaries and only those line up much as blood does.

Fully built; personal vehicles from power chairs to scooters come with you for the last mile, and shared, miles of parking are not needed and availability predicted so little wait, and precise shortest route expected. Private vehicles can be accommodated, but unnecessary, as ease of use for the upper classes would assure funding and maintenance (and why busses fail for all who can afford otherwise)

With a net huge area; solar power with batteries could power the entire system but can come later

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