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Response to jollyreaper2112 (Reply #15)

Thu Feb 14, 2013, 10:17 PM

16. You are trying to do a Mass Transit Patch on a Automobile transit system


THe problem is simple, the entire system is the problem. PRT can NOT fix that inherent problem. Pedicars would be a better retrofit. I always joke about my old home town of Pittsburgh PA, it was designed for people to tie you canoe up on the river bank and then walk into town. Streetcars were a good retrofit, for they could move a lot of people five to ten miles so they could disembark and walk to another Streetcar or walk to where you are going. Automobiles were a bad retrofit, for that require wider roads, faster roads that had the secondary feature of reducing population density, making Streetcars less competitive.

In Suburbia you do NOT have any large group of people going in any one direction. Given that situation for a PRT to work, you will have to duplicate the entire road system AND maintain the present road system. That double cost is what is the real killer behind any PRT. Which system gets priority? Auto drivers including truck drivers will demand that it be the highway.

Now, the same complaint can be made about LRVs, but LRVs are intended to move a large number of people from one area of high population density to other areas of equal or less population density. if fed by people who walk can easily move thousands. If the system add park and rides, can move even more people. PRTs, if design as a true PRT (instead of a small LEV) can do the same, but you need a decent population density to justify it to people whose first choice is the public highway system.

For example, if I was designing a transit system for a Modern City. I would look at the present highway system to see where are the bottlenecks and then try to figure out why they occur. More often then not you have people wanting to go through these bottle necks to go to or from a common area, more often then not a "Downtown" or similar business/Commercial/Government Center. I would then put in an LEV system from such center along (or under) such a highway to the other side of the bottleneck and install a Park and Ride at that location. To purpose is to get people to drive to the Park and Ride not to the business/Commercial/Government Center. I would have buses also running to such Park and Rides.

Inside the Bottleneck I would also run a series of elevated what in Pittsburgh was called "Skybus", an automated system, with LARGE cars that picked people up every couple of blocks. Unlike the LRVs that would have few stops, these "Skybuses" would stop frequently and then always at an LEV stop. Some of the "Skybuses" I would run par rel to the LRVs, but most would run between LRVs lines to connect them up. People would have to move from an LRV to a "Skybuses" or even to walk to get to they final destination. I would also look into automating the LRV, all to reduce operating costs.

Here is a Picture of the Skybus automated system, proposed in the 1960s to replace the last Streetcar Line in Pittsburgh. When a Study was actually done, it was found that replacing the old PCC Streetcar system with a rebuilt LRV was cost effective, thus Skybus was never built but an LRV system was built instead:


One of the problem with Skybus was it was intended to replace a Streetcar system that even today beings in 10% of all workers into Downtown Pittsburgh AND traveled on its own right of way, i.e. independent of the road network. Because it existed, peopled settled near it and a good Park and Ride system existed even in the 1960s along with extensive sidewalks to get people to the streetcar stops. If it had been used to replace the normal streetcar that traveled on public highways, it would have been a success, but it was NEVER intended for that purpose, the local transit service preferred regular buses on those routes. On the last Streetcar line, if it was abandoned and replaced by buses, any trips would have doubled or triple in time (even today, if you get on the LRV at its last stop, and someone else drives his car from that stop to Downtown Pittsburgh, the Car will beat the LRV if you exclude the time needed to park the car and walk from the parking lot to actual downtown).

Now, I would also build Skybuses from various areas outside the bottlenecks to the LRVs stop in the other-side of the Bottlenecks. Within the Bottlenecks, all service from the LRV stops would be by foot, bike or Skybus. Outside the Bottlenecks access would be expanded to buses and automobiles.

Such an integrated system would be roughly the equivalent of the present highway system, i.e. Interstates and other limited Access highways are the equivalent of LRVs, local streets are the equivalent of Skybus within the Bottlenecks, and Buses, Skybus, Automobiles, bicycles and walking.

PRT is an attempt to replace buses, trains, "Skybuses" LRVs with one system, it is like replacing Limited Access Highways, Four Lane Highways and local roads with two lane highways (To fast for local housing, but to small to move what an limited access highway can do). Thus the problem of PRT, to small to move a large number of people, and to large to replace walking. Thus a solution looking for a problem to solve.

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jollyreaper2112 Feb 2013 OP
Lydia Leftcoast Feb 2013 #1
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jollyreaper2112 Feb 2013 #3
happyslug Feb 2013 #14
jollyreaper2112 Feb 2013 #15
LineLineLineNew Reply You are trying to do a Mass Transit Patch on a Automobile transit system
happyslug Feb 2013 #16
jollyreaper2112 Feb 2013 #17
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