Personal rapid transit

[lord of the mark]

Re: Re: Re: Personal rapid transit

Originally posted by Thue


That ignores advantages like pollution, safety, and non-cluttering of roads.

At least it would make sense to make PRT systems instead of the current subways/city railways.

The fact that making subways makes enough economic sense for them to be made, even if some of them cost 90M€/km, also indicates to me that PRTwould make economic sense.

subways make sense in select places cause they get economies of scale from multiple people per car, and multiple cars per train. If its going to be strictly personal there are few advantages to a rail based system vs fully automated, electric rubber tires on roads. Only real advantages are A. the battery problem and B. Ability to squeeze more infrastructure in crowded areas A is likely to be resolved before your system is built anywhere, and B is an issue only in select places. In general its far easier to maintain roads than rails, the cost of construction for elevated systems and rails is very high. the advantage of being able to pass is significant, etc, etc.

And youre blocking a lot of sunlight if you use elevateds. If you build subways, the cost per mile is even higher.

[Datajack Franit]

Does anyone actually give a damn about cars polluting?

[DanS]

Not me.

[lord of the mark]

Originally posted by Spiffor

"Low density" has a different meaning in Europe and in the US.

In Europe, you can perfectly have a tightknit village of a few thousands surrounded by fields, not too far from the centre, which justifies a station because the villagers can go to the station by foot or bike. That's very different from the US suburbia.

that is correct, though pre-auto there were some US suburbs that fit that pattern, esp in parts of Greater NY, Philly, and Boston, largely built around commuter RR stations, or in some cases, "trams" (See streetcar suburbs)

There is a movement afoot, the new urbanism, to build new suburbs more like that, or to retrofit villages into older suburbs. The real problem is one word in your post - stations. You can justify a station on an existing rail line much more easily than a new rail line. So in places like Chicago, with an existing network of freight rail lines, its far easier to add commuter services, than in somewhere like DC, where there were never many rail lines. Today, as DanS knows, virtually every one of the old rail lines around DC has commuter service. But new lines can only be justified by metro level service, which requires much higher densities.

[lord of the mark]

Originally posted by Datajack Franit
Does anyone actually give a damn about cars polluting?

Sure, But most of the pollution benefits of transit are due to economies of scale. If youre running personal transit vehicles, youre not doing much better than cars on roads, except that theyre electric, depending on how you generate your power. and again, electric cars a possibility.

[lord of the mark]

Originally posted by LordShiva
None of those cities are anywhere close to LA's size.

DC and New York have excellent subway systems. Phillie's is crap, though.

LA, in case you havent noticed, is laid out differently. Its downtown was never as dominant a place of employment, and its densities were too low. (also snow and ice as motives to avoid driving are significant in North America) Today, as peripheral employment centers have gotten bigger, and densities have grown, LA has build several lines. IIUC they are looking at more. They also have several commuter rail lines. But they started from virtually nothing not long ago, and they have a long way to go, and still much of the area is too low density for any rail transit to work.

BTW LA has one of the highest volume bus systems in the US.

[Datajack Franit]

Unless we're talking about Hydrogen buses, they still pollute

[lord of the mark]

Originally posted by Datajack Franit
Unless we're talking about Hydrogen buses, they still pollute

so does electricty generation for rail systems, as well as the processes used to build rail systems. Its just a question of the best tradeoffs in any situation. In many buses are the best transit solution.

[Thue]

Originally posted by OzzyKP
Nor Copenhagen...

That is only part of the Copenhagen train system. The other part:



Also, there is an extensive bus coverage.

[FrostyBoy]

I've been on the thought of PRT's for many years.

I have come to the conclusion that the ideal way to change from roads to rails is to have all new apartment buildings and office buildings require the facilities to connect to the new rail lines. Eventually, maybe in 50-100 years, roads can be completely replaced by rails.

This is not something you can do within a 10-20 year period. But it is definitely worth doing and probably inevitable.

[Datajack Franit]

Still, this looks like an awful lot of space that could have a better use

[Odin]

Originally posted by DanS

The fact is that for about 80 years, the US has taken the enlightened approach and embraced the automobile.

Traffic jams, tons of pollution, and suburban sprawl is enlightened?

[Odin]

Originally posted by DanS
Not me.

[GePap]

Originally posted by DanS
DC's Metrorail is a special case. It was constructed mainly through federal funding because DC is a capital city. Strictly on economic grounds, it probably would not have made sense to build it, as evidenced by the fact that very few other US cities have extensive subways.

Basically, New York City's subway stands alone. But I note that even the NYC subway has not grown in the last 50 years.

building undergound tunnels, specially in areas with immense undeground development is very costly. If the NYC subway has not grown, is because the funding necessary has never materialized. Hopefully in the next 20 years we will finally see some epxnsions come into play once people enlighten themselves away from the automobile in a dense urban center like NYC.

[DanS]

In the early 1900s, even my home town of 1,400 in Ohio had passenger rail. But about 80 years ago, the station shut down. Why would it have shut down, if it was the best way to do personal transportation?

It's obvious that cars have been the way to go for about 80 years now.