The Gondola Project

Comments

1. ant6n

   May 6, 2010 – 10:22 am

   Mmmh, how about they are slow, and they don't have a high enough capacity to replace 'real' rapid transit?
2. Steven Dale

   May 6, 2010 – 10:27 am

   Actually you'll find that most cable transit systems operate at speeds equal to most other 'real' transit systems. That's because in urban environments speed is not dependent upon technology and is instead dependent upon station spacing and route alignment. Because these systems operate outside of mixed traffic, they often witness speeds higher than things like light rail and buses. It's not going to replace high speed rail, of course, but high speed rail isn't a form of urban transit. As for capacity, there isn't a single light rail or bus line in all of North America that moves more than 3,700 persons per hour per direction. Advanced cable transit systems are capable of up to 5,000 - 6,000. Speed and capacity are the two most commonly used arguments against cable and the facts just don't support those arguments, but thanks for bringing them to the table.
3. ant6n

   May 7, 2010 – 12:26 am

   Interesting. But then you have to make clear what your gondolas are competing against. For a metro system for example, 6000 passengers per hour per direction are not all that much. It seems you try to provide an alternative to bus (non BRT) or light rail (probably more like street car systems). Do you have a source for the 3700 hour per person per mile claim? On a side note, 6000 passengers seems like a lot for a gondola system. In a recent post you mentioned that some system with 200 passengers per gondola is one of the highest capacity in the world. But this system would still require a seemingly high frequency of 2 minutes. At the same time this particular gondola was large, and a 2 level system. This again would be fairly large, and it might not fit well into the urban fabric. Your gondola advocacy is quite interesting, and it might represent a viable form of urban transport. But I think the possible use cases (what 'space' does this technology possibly occupy?) could be made clearer. Also, people probably need a bit more convincing than your posted argument.
4. Steven Dale

   May 7, 2010 – 12:47 am

   Let me just go through things one-by-one: a) If you look through this website, you'll see that I'm not suggesting CPT compete against metro systems. At the same time, when you break things down to a cost per rider per kilometer, you do see that CPT comes out ahead (generally speaking, there are always exceptions, of course). b) I am talking about using this as an alternative to medium capacity systems such as BRT & LRT largely because metro construction seems to have stopped in North America due to worries about cost and ridership. That doesn't mean, however, that I'm not hopeful the tech might one day be able to compete with metro systems. c) As for my 3,700 pphpd claim, that's based on gathering the statistics from every light rail system in North America. There's no single repository of that information and in my professional work I've had to assemble those statistics. It was honestly quite surprising to see how low those numbers are. On average, most float around 2,000. You can find these statistics through any transit agency, it just takes a bit of digging. d) Your comment about the 6,000 vs. 200 raises an interesting point. System capacity is not the same as vehicle capacity, a mistake which is often made. System capacity measures the number of people a line can process in a given period of time in a given direction. Vehicle capacity is merely the number of people one single vehicle can process. Currently, the 5-6,000 pphpd maximum is achieved by using a detachable vehicle that carries up to 35 people with a frequency of 15-25 seconds. e) As for the "posted argument" you point's well taken. Sometimes I forget that some people will come to this site for the first time and see an "argument" like that. I think I've tried to make a convincing argument throughout the life of this site but as many of those posts are buried pages deep within the blog maybe I should try and extract those and make them more readily available for people. It's a good point you make and I appreciate it.
5. matthias

   May 7, 2010 – 3:59 am

   What is interesting that especially Americans think the different technologies most be competing each other. Instead they are all tools. Is a hammer competing with a screwdriver in the toolbox? So gondolas are just a tool with its strength and weaknesses. As you can use a screwdriver to do some hammering you also could use gondolas to replace a heavy metro. Gondolas can be efficient feeder system to rail lines, where a destination has to be reached uphill or downhill the train station, between the destination and the train station is a deep valley, river , highway or any other impassable terrain. In this cases it is better to build an cable powered connector line than spent hundreds of million to move the train station to the destination or build an expensive road to do the same task. I guess gondolas are the cheapest type of bridges and have transit built in already.
6. Steven Dale

   May 7, 2010 – 4:05 am

   An excellent point, Matthias, and one that I try and reinforce. Cable is just one of several options. I think we find ourselves drawn into the whole LRT/BRT/CPT debate because of the assumption people make about cable being too slow without enough capacity. The only real way to dispel that misinformation is to compare it directly to standard modes. It's unfortunate that it happens, but I'm not sure there's way around it. Any ideas? How do you demonstrate that CPT is fast enough with enough capacity but not rely on comparisons to standard transit modes. Now that's something I'd love to discover.
7. Matthias

   May 9, 2010 – 6:23 am

   Capacity is not the problem and for speed most people just consider maximum operation speed or even maximum speed. The most common type of cable propelled systems are elevators and escalators. Without this invention many modern buildings would not be possible and the highest building would be restricted to five or six storeys because no one what to climb more stairs. A CPT system can work in a similar way. It can be used whee distances for escalators or elevators are to long. But station spacing of traditional transit to short. average walking speed is about 1m/s and many research show that people are willing to walk 5 minutes to the nearest transit stop. Thats 300m Walking distance. This will lead to very short station spacing and makes two level of transportation needed. First a regional transit, usually heavy rail with station spacing of a few kilometers and a distribution network using tram,bus and cpt which will serve on more several station of the regional system. subway or metro system can fit in either category. Cities which use only one level of transport have long walking distances to stations and a slow line speed due to relative short station spacing. Unfortunately this approach is not widely discussed in North American transit websites, as most only focus on one mode. Some eastern European cities have very deep lying subways. If they have two ore more escalators from platform level to the ground the entrances of one station lay several hundred meters apart, a distance which equals one tram or bus stop. With this approach station spacing is relative long but they still can cover a great area within walking distances of a station because of the long and fast escalators. CPtcould work in a similar way for surface stations.
8. Ryan_OC_NZ

   May 9, 2010 – 5:08 pm

   Good points Mattias, but I think you could revise how far people are prepared to walk to transit. I have come across many studies that point to 400m for standard bus services, 800m for a high quality transit modes BRT or LRT, and 1200m for high capacity lines such as commuter rail. I think aerial ropeway transit (in particular) you could be looking between 600 - 800 metres walking distance (or 10 minutes), due to the following facts - strictly due to very high frequency (less than a minute) and reliability. I have done some studies myself in comparing the pros and cons or LRT, BRT and aerial ropeways and have found all have similar average speeds in a urban environment, this is partly because many BRT and LRT systems have only semi-prioritized ROWs. Complete separation from traffic for BRT and LRT will outperform average speeds of most ropeway systems, however there build costs are significantly more, and removes road space, unless elevated (which is more expensive again). I do not agree to your two tier transport hypothesis, this is somewhat true for large cities, however I think in smaller/medium cities or particular situations aerial ropeways can act as a stand alone transit system. This is because the capital and maintenance costs of LRT are so high it is not affordable. Of course certain characteristics need to provide benefit over prioritised buses. Centralized activity centers, constrained road space and effective land use initiatives (i.e. TOD) paint a very favourable case for a stand-alone aerial ropeway transit system. Of course it is a tool for the urban environment, one to be compared with other tools for the job. I do like your toolbox example, because it is completely the case. We as transport professionals need to look all transits systems and match them accordingly to their best suited applications.
9. matthias

   May 10, 2010 – 5:06 am

   My data are from Zurich, Switzerland which is well known for good transit. Bus and Tram stops are spaced 350m-450m because even in Switzerland people would use cars if they have to walk to far. And every of that stops is served at least every 7.5 minutes per direction inside the city. Many people think most traffic is to go to work or school but that portion is actually less than half of the total traffic. If you go shopping you do not want to carry your bags more than five minutes. Internationally Zürich is a small city and the greater area has 1 million citizens. Still we have a two tier transportation system. Tram proponents often city Zürich as a model city for trams but tend to neglect the effects of the S-Bahn commuter rail. Bigger cities have even a three tier approach: Bus/tram then metro then regional rail. I do not like the term LRT because it can be anything from a streetcar to a fully automated metro system.
10. Steven Dale

    May 10, 2010 – 12:00 pm

    Matthias: I'm not big on the LRT term either because it's just too wide in scope. At the same time, we're using CPT to describe a wide variety of technologies, but I think we're doing a good job differentiating between each form. I'm quite familiar with Zurich's transit system and I've always found the commuter rails much better than the Trams largely because of the long wait times between vehicles and because they operate in mixed traffic. They are, however, very charming to look at and ride!