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    Senior Member coldfeet's Avatar
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    Opinions on Personal Rapid Transit.

    Looking for opinions on Personal Rapid Transit,

    http://en.wikipedia.org/wiki/Personal_rapid_transit
    http://www.personalrapidtransit.com/

    Have a look, tell me if you think it is a good idea or not and why.

    I'm all for cycling, but i wouldn't expect everybody to want/be capable of cycling
    everywhere/everywhen.

  2. #2
    not a role model JeffS's Avatar
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    I think it's a good idea in an environment built around it -- which obviously doesn't exist.

    The cost factors (comparisons to the cost of roads) are only really applicable if they are a replacement for roads, or if you can calculate an exact cost benefit. For example, "we can spend X m(b)illion on road expansion OR we can institute PRT.

    The problems I see are much the same as those that affect other mass transit options. An incomplete system is of little use. Unfortunately, "complete" to many people means servicing the suburbs. My personal stance would be that any mass transit should serve the core completely first before worrying about the outlying areas. Unfortunately, getting this past the voters is almost impossible. As a result, cities like mine are paralyzed, incapable of doing anything other than building more roads.

  3. #3
    Two H's!!! TWO!!!!! chephy's Avatar
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    I'm sure removing the humans from behind the wheel will be good. Fewer accidents, no road rage...
    Stomping as lightly as I can...

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    Senior Member coldfeet's Avatar
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    Quote Originally Posted by JeffS View Post
    I think it's a good idea in an environment built around it -- which obviously doesn't exist.

    The cost factors (comparisons to the cost of roads) are only really applicable if they are a replacement for roads, or if you can calculate an exact cost benefit. For example, "we can spend X m(b)illion on road expansion OR we can institute PRT.

    The problems I see are much the same as those that affect other mass transit options. An incomplete system is of little use. Unfortunately, "complete" to many people means servicing the suburbs. My personal stance would be that any mass transit should serve the core completely first before worrying about the outlying areas. Unfortunately, getting this past the voters is almost impossible. As a result, cities like mine are paralyzed, incapable of doing anything other than building more roads.
    Why would it be unable to add to a road system? Most of the proposed systems involve light overhead rail which can share roadways.

    Agreed that it would have to cover an reasonable area before it became useful, but once you have say, downtown covered, why could you then not add sections as desired? I think of this as a replacement/alternative for something between buses and taxis.

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    Senior Member coldfeet's Avatar
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    Quote Originally Posted by chephy View Post
    I'm sure removing the humans from behind the wheel will be good. Fewer accidents, no road rage...
    I definitely agree, I think we may be in a minority though. I fear one sticking point would be distrust of automated systems.

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    Senior Member Smallwheels's Avatar
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    I would love to have one of these systems in operation in every town. With computer chips so fast and inexpensive these days, coupled with the radar technology used by some automobiles for automated parking, this would seem to be an ideal solution for the people who won't ride mass transit because of associating with people they find distasteful. Since the systems would be 2-5 times faster than bus service and even faster than private automobiles in rush hour, there would be few excuses for not utilizing such a system.

    Such systems would easily be expandable with the advent of GPS or other sensors in the roadbed. Connecting new segments would be very easy to do.

    In the second link in the first post there is a presentation of PRT. At the end of it there is an image of a passenger in one of the modules with his full size bicycle. That is a great combination of transit modes.

    It would be great if these were linked throughout the USA and Canada. Imagine swiping a credit or debit card and taking ones own little pod to another city. One could transfer into the next cities system and continue to the next city beyond that until the final destination is reached. It would almost be door to door service.

    The only people who would be afraid of using an automated PRT system are people who are afraid of using elevators. Most of us use elevators at one time or another. They are probably the most widely used automated people transportation system in the world. I have been stuck in elevators three times. Two of those times I had to force the doors open and climb up about four feet to get out. The other time the elevator just sunk to the basement because it was overloaded. The doors needed to be forced open then too. I still ride elevators and rarely even remember those times I was stuck.

    Bring on the PRT!
    Smallwheels

    Take my stuff, please. I have way too much. My current goal is to have all of my possessions fit onto a large bicycle trailer. Really.

  7. #7
    Sophomoric Member Roody's Avatar
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    In terms of energy efficiency, I don't see how the PRT would be much different than a private car. I guess it could be programmed to take the most direct route, and there wouldn't be any stop and go, but I don't see any other efficiencies. What am I missing?


    "Think Outside the Cage"

  8. #8
    Senior Member Smallwheels's Avatar
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    The Wikipedia site explains that a PRT unit should weigh no more than 600 pounds and carry three or less people. The unneeded cars just stay parked until someone requests one. Since the pods don't travel unless in use or when being sent to the busy section during peak hours they average a higher average occupancy than busses. These things combine to make it twice as efficient as a bus running at full capacity.

    Busses often run almost empty in the off peak hours which makes them very inefficient. Surely if everyone rode mass transit instead of using cars the busses would be more efficient, but that won't happen (in the USA).
    Smallwheels

    Take my stuff, please. I have way too much. My current goal is to have all of my possessions fit onto a large bicycle trailer. Really.

  9. #9
    www.chipsea.blogspot.com ChipSeal's Avatar
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    They are different in weight and propulsion. To keep weight down, they use small electric motors with no batteries.

    These would also work well to connect the "outside ends of the spokes" to compliment existing mass transit systems, rather than forcing a trip downtown before you get to your destination.

    The overhead design makes routing flexible and inexpensive, and doesn't create crossing barriers like light rail does. Overall system cost should be competitive with a new buss routes when road wear and liability are factored in.

    Bike racks are a must though!
    Vehicular cycling techniques have not been tried and found difficult. They have been presumed difficult and not tried.

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    The idea has been kicked around for decades, but a fully functional one has yet to be built. The closest thing is the one in Morgantown, and even that is not a pure PRT. Let's see how one works in practice before making a judgment one way or the other.

  11. #11
    Senior Member maddyfish's Avatar
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    It's fine, as long as it moves very slowly, never, ever hits anybody, and I don't have to pay for it.
    I don't pay for fat peoples, cripples, or old people's cars now, I don't want to pay for thesethings either.
    Not too much to say here

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    Quote Originally Posted by coldfeet View Post
    Looking for opinions on Personal Rapid Transit,,,,

    Have a look, tell me if you think it is a good idea or not and why...
    It's a bad idea, because it's trying to combine two opposite transportation schemes: mass-transit and individual-transit.

    Mass transit is only valuable when you have a lot of people who want to travel between (roughly) the same places, and in practice it becomes less efficient the more places that it covers.

    Big urban areas have this problem of transportation--you always see the problem of urban mass-transportation systems running mostly-empty. Also the peak use is only at two times, and isn't symmetrical--because of people commuting in to the city in the mornings, and going outbound at night--so any mass-transit system is going to be running basically half-empty even at peak-use times, and very-much-less than half-empty the rest of the time.

    So the question of efficiency then becomes: what mass-transit system is cheapest to run at low capacity? And the answer is..... roads. Like, for automobiles. Those automobiles could be gasoline powered, or electric, or whatever--but the reason that roadways are the "cheaper" form of transportation to put in, is because a large part of the cost of them is borne by the individual, in that the individual has to buy their own car. And the individual has a wide variety of choice in how expensive of a vehicle to buy, or even to not buy a vehicle at all.

    Cities don't have room for more roads, at least at ground level. So the better answer here is to either start building muti-level roads, or to force urban areas to spread out more (perhaps by taxing employers highly per-person, to drive big employers out of urban areas).

    What urban areas NEED is a small inexpensive enclosed trike with climate control, with only one or two-person capacity, powered by a small gasoline engine of 250cc's or less. These would put less wear on roads, less pollution and less parking space needed but would still allow individuals to travel independently. ....We have motorcycles now, but they're not attractive in anything but mild weather, and even then they have drawbacks (mostly they have no good lockable storage or climate control).
    ~

  13. #13
    not a role model JeffS's Avatar
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    Quote Originally Posted by Doug5150 View Post

    Cities don't have room for more roads, at least at ground level. So the better answer here is to either start building muti-level roads, or to force urban areas to spread out more (perhaps by taxing employers highly per-person, to drive big employers out of urban areas).
    ~
    This is the first time I've ever heard someone advocate sprawl as a solution to congestion. I have to say, I think this is one of the worst ideas I've ever heard.

    Transportation costs get increasingly more expensive the further from center you move.

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    Quote Originally Posted by maddyfish View Post
    I don't pay for fat peoples, cripples, or old people's cars now, I don't want to pay for thesethings either.
    Thank you, Mr. Scrooge.

    A decent mass-transit system is one of the amenities of urban living, along with sewers, roads, piped-in water and gas, etc. What form it should take in a particular community is a matter of debate.

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    Quote Originally Posted by JeffS View Post
    This is the first time I've ever heard someone advocate sprawl as a solution to congestion. I have to say, I think this is one of the worst ideas I've ever heard.
    The question is, would it work or not?

    Quote Originally Posted by JeffS View Post
    Transportation costs get increasingly more expensive the further from center you move.
    Further from the center of what?

    The problem of congestion is people trying to get to their jobs,,, of people not being able to live close to their jobs to make things like bicycling practical--and it's mostly only urban areas that suffer the problems of congestion. You can move the people, or move the jobs.
    ~

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    Senior Member wheel's Avatar
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    Why don't you see a drawing of one of those things above freeways or next to power lines (high voltage).

    Sprawl where I live is Economy.

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    Senior Member maddyfish's Avatar
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    Quote Originally Posted by Elkhound View Post
    Thank you, Mr. Scrooge.

    A decent mass-transit system is one of the amenities of urban living, along with sewers, roads, piped-in water and gas, etc. What form it should take in a particular community is a matter of debate.
    But this really isn't mass transit. This is personal transit. I don't mind paying for the roads, I don't mind paying for a cab when I'm in it, paying for a bus when I'm on it, but I'm not paying for somebody else's persoanl transit.
    Not too much to say here

  18. #18
    In the right lane gerv's Avatar
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    After think about this a while, this system seems to me like a public transportation concept with private accommodation aboard... sort of if you had private compartments aboard the bus. I say this because:
    1. I don't see how you could go completely from any point to any other point in the city. You would have to get off at some kind of stop and then hoof it to your destination.
    2. You would probably have to wait to be "scheduled" to avoid any massive traffic tie-up.

    Sounds like a bus to me.

  19. #19
    rhm
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    The system sounds marginally better than everyone owning and driving a car, but I doubt it would be that good if everyone gave up the car and relied on the PRT system. A better solution would be to get rid of cars and let everyone walk or ride bicycles....

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    Quote Originally Posted by rhm View Post
    The system sounds marginally better than everyone owning and driving a car, but I doubt it would be that good if everyone gave up the car and relied on the PRT system. A better solution would be to get rid of cars and let everyone walk or ride bicycles....
    And what of those who are physically incapable of riding bicycles, or live in terrains or climates unsuitable for cycling, or have to carry loads to heavy or bulky for bicycles, or travel longer distances than are practical on a bicycle, or some combination of the above?

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    Senior Member coldfeet's Avatar
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    Quote Originally Posted by Roody View Post
    In terms of energy efficiency, I don't see how the PRT would be much different than a private car. I guess it could be programmed to take the most direct route, and there wouldn't be any stop and go, but I don't see any other efficiencies. What am I missing?
    You have answered most of the question already, no stop and go direct route, no delays except for possibly some at very popular drops/pickups. For example, currently my commute takes about an hour by bus or bike, if I had a car it would be 25 minutes on a good day, averaging 30 minutes maybe with the potential in bad traffic or weather of up to 90 minutes. PRT would be 15-20 minutes with a high reliability factor. Pollution would be dependent on the source for the electricity so could be clean.Energy consumption should be anything from 1/3 to 2/3 that of most other transit systems on a passenger mile basis and much lower than an IC car. Noise pollution is at the level of a golf cart. High density drops/pickups could be taken care of by larger stations with multiple access routes.e.g. at sports stadiums, malls, connections to long distance transit options etc.

    The big advantage as I see it, no schedules, anytime I want to go, I walk to the nearest stop and call a pod.

  22. #22
    Senior Member coldfeet's Avatar
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    Quote Originally Posted by ChipSeal View Post
    They are different in weight and propulsion. To keep weight down, they use small electric motors with no batteries.

    These would also work well to connect the "outside ends of the spokes" to compliment existing mass transit systems, rather than forcing a trip downtown before you get to your destination.

    The overhead design makes routing flexible and inexpensive, and doesn't create crossing barriers like light rail does. Overall system cost should be competitive with a new buss routes when road wear and liability are factored in.

    Bike racks are a must though!
    Most of the popular designs are big enough for 2 adults with bikes. See the second link and follow the presentation and it shows a guy with a bike in the pod.

  23. #23
    Senior Member coldfeet's Avatar
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    Quote Originally Posted by maddyfish View Post
    It's fine, as long as it moves very slowly, never, ever hits anybody, and I don't have to pay for it.
    I don't pay for fat peoples, cripples, or old people's cars now, I don't want to pay for thesethings either.
    Do you live in a city with transit services now? That is any good? Chances are your taxes are subsidizing it. This system should be efficient enough to run revenue neutral or possibly at a profit. If it is overhead, it couldn't hit anything.There are new risks involved, which is one of the sticking points, but overall the risk should be lower than current systems.

  24. #24
    Senior Member coldfeet's Avatar
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    Quote Originally Posted by Elkhound View Post
    The idea has been kicked around for decades, but a fully functional one has yet to be built. The closest thing is the one in Morgantown, and even that is not a pure PRT. Let's see how one works in practice before making a judgment one way or the other.
    You have hit the big one on the head. Chicken and egg, I think the first proper PRT will be in Scandinavia or Japan. Once it is in and working, I think the city involved will be swamped by fact-finding visits by other cities. People en-mass tend to be too comfortable with the status quo.

  25. #25
    Senior Member coldfeet's Avatar
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    Quote Originally Posted by Doug5150 View Post
    It's a bad idea, because it's trying to combine two opposite transportation schemes: mass-transit and individual-transit.

    Mass transit is only valuable when you have a lot of people who want to travel between (roughly) the same places, and in practice it becomes less efficient the more places that it covers.

    Big urban areas have this problem of transportation--you always see the problem of urban mass-transportation systems running mostly-empty. Also the peak use is only at two times, and isn't symmetrical--because of people commuting in to the city in the mornings, and going outbound at night--so any mass-transit system is going to be running basically half-empty even at peak-use times, and very-much-less than half-empty the rest of the time.

    So the question of efficiency then becomes: what mass-transit system is cheapest to run at low capacity? And the answer is..... roads. Like, for automobiles. Those automobiles could be gasoline powered, or electric, or whatever--but the reason that roadways are the "cheaper" form of transportation to put in, is because a large part of the cost of them is borne by the individual, in that the individual has to buy their own car. And the individual has a wide variety of choice in how expensive of a vehicle to buy, or even to not buy a vehicle at all.

    Cities don't have room for more roads, at least at ground level. So the better answer here is to either start building muti-level roads, or to force urban areas to spread out more (perhaps by taxing employers highly per-person, to drive big employers out of urban areas).

    What urban areas NEED is a small inexpensive enclosed trike with climate control, with only one or two-person capacity, powered by a small gasoline engine of 250cc's or less. These would put less wear on roads, less pollution and less parking space needed but would still allow individuals to travel independently. ....We have motorcycles now, but they're not attractive in anything but mild weather, and even then they have drawbacks (mostly they have no good lockable storage or climate control).
    ~
    I partially agree with you, it does allow you you private use of a pod, this is where I think it will increase substantially rider numbers. The transit where I live is... not too bad, but i still end up getting jammed in with packs of people, some of who don't have as intimate a relationship with soap as one would like. The peak use problem doesn't go away, but simulations have shown PRT works better than anything else, by a large margin. I've just started playing with this free simulation tool, I'll report back if I can get any meaningful results.

    http://faculty.washington.edu/jbs/itrans/simu.htm

    A light trike is something I might buy, but a lot of people in North America wouldn't dream of driving in a Smart, what makes you think they would go for something smaller? I do think they will start to appear in increasing numbers as the fuel problems start to become more obvious, but a PRT allows you to sidestep a lot of the problem. Nothing is perfect but I think this comes closer than other proposed solutions.

    Edit: Missed some of your points, I couldn't get back to this for a couple of days and there are a lot of points to consider.

    If you look at the way the system operates, it eliminates the spoke and hub and transfer problems of light rail/bus/trolley transit. Its a grid, a somewhat poor analogy is to consider railway or going further back, stagecoaches, as the equivalent of the telegraph, city buses or light rail could be compared to a telephone, PRT could be likened to the internet. As far as your comment about allowing urban areas to spread out, are you advocating more sprawl, or do you want to see outlying areas become more self sufficient? Work, shop, play in the same "village"?
    Last edited by coldfeet; 01-03-08 at 08:51 PM.

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