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You can read about Japan's Maglev project here Yamanashi Maglev.

Actually, the maglev line will not run parallel to the Shinkansen line on the coast, but will go through the mountainous regions of central Japan, incorporating the test line segment in Yamanashi. The line will act as a backup in case the existing Shinkansen line gets destroyed by a major earthquake or a volcano eruption (specifically Mt. Fuji).

yes... there is a lot of stops I think this may be outdated already... but it illustrates well... :)

There is a MagLev test line under development in the Yamanashi perfecture, that can currently do 310 mph; it is quite a treat to watch, and if you get lucky you can get a chance to ride it. More information here in English, with some videos here. True, it's been around damn near ten years and they haven't started public service...

Yamanishi Maglev Overview

Japan has been R&Ding Maglevs since 1970. They should replace today's shinkansen (bullet trains) in a near future

I've been fascinated with Maglev technology since I was a kid, though I admit I haven't followed it closely lately - I didn't know a functioning passenger transrapid had been built in China.

Anyway, I have long been extremely annoyed that Transrapid's maglev technology has been the one to catch on the fastest, because as I see it, it has some major drawbacks relative to other maglev designs.

The primary problem is that the transrapid system uses magnetic levitation in attraction mode -- meaning you're not floating mutually repelling magnets, you're wrapping a part of the train under the track and using magnetic attraction to pull it upward.

There are some huge basic problems with this strategy. To start with, magnetic attraction is dynamically unstable - the closer you get, the harder it pulls, until you stick to the track. Transrapid deals with this by detecting the gap and constantly adjusting the current to the electromagnets with a fast computer. Magnetic repulsion, on the other hand, is dynamically stable: float a magnet over the other one and it will simply sit there, so fast computer needed. The Japanese design functions this way: the train sits in a U-shaped track, repelled on three sides.

There are some other serious advantages of repulsion-mode maglev:

• repulsion-mode trains maintain a gap of several inches between train and track, transrapid maintains a gap of about a centimeter. This means small bumps and flexes in the track (due to tides, thermal expansion, inexact design) get smoothed out much better by a repulsion-mode maglev. Consequently you don't have to build the track to such exacting specifications, making it much cheaper.
• in attraction-mode trains, the track has to be powered to activate electromagnets along the entire length. In repulsion mode, coils embedded in the track are induced by the moving magnetic field of the train: totally passive track, no power required. A repulsion-mode maglev doesn't need to worry about power outages, and the track is cheaper to build and maintain.

The major downside of the repulsion design is that it requires superconducting electromagnets on the train, and they're very expensive (for now) and can cause interference problems if not properly shielded, as someone noted above. But I see that as a technological problem that will be solved eventually and it would be better to work on that now than to saddle ourselves with a standard that has the fundamental problems of attraction-mode maglev design. Sixty years down the road when superconducting magnets are cheap, we might really regret that.

There's another minor downside to repulsion maglev as well- it only levitates when the train is going fast enough to induce currents in the track, so the train has to settle onto wheels as it rolls into the station. (or have supplementary electromagnets in the station).

Both the Japanese and transrapid designs have one other problem: the tracks have to pre-define the angle of the train as it rounds corners (the japanese track is a square "u"). You determine the speed beforehand and angle the track so that the force vector on the passengers is "down" with respect to their butts. This means you can't change the speed of the train later without making it ride like a roller coaster, so no faster trains down the line, and no adjusting speed for current conditions. And it means you have to manufacture very carefully-designed track segments at precise and constantly-changing curvatures. You either have standard track segments and limit the curves you can build, or build a lot of custom track segments. This gets expensive.

IIRC, there was a design done by a team in the US two decades or so ago that used a curved U-shaped track in repulsion mode that had the benefits of the japanese de

• the japanese are doing it right. slow, methodical, engineering-sensible development will probably result in a chuo-shinkansen maglev in 10-15 years at the longest and possibly in as little as 5-10 years. See here for a gentle introduction.
• the chinese are building a maglev shanghai-beijing. every engineer or knowledgable person i have ever spoken to has said that this was a rushed through engineering abortion; an inefficient showpiece really. still, there's something to be said for having it done first, and, if the chinese do it, then more power to them.
• 14 million of research from an ab initio program isn't enough to make a toilet handle on a maglev train. a maglev is something at least as complicated as a 777 given all the supporting things that need to be built such as stations, emergency vehicles, turnouts (switches), safety devices, computer systems, and so forth. 14 million for a maglev project is GUARANTEED not to go anywhere other than perhaps some basic research in electrical systems that the japanese have done long ago.
• a maglev is PERFECT for:
  • the US northeast corridor
  • london-edinburgh via manchester/liverpool
  • tokyo-osaka via the chuo-shinkansen route (duh).
  • hong kong - guangzhou - shanghai

The referenced link is for TEST TRAINS that do not carry regular passengers. Where is there a MagLev anywhere in the world providing passenger service? This is exactly why I compared it with the personal flying car. We've all seen the Moller SkyCar. It can be done in small experimental scales, but is it too impractical/expensive/dangerous for regular service? On the economic viability especially, what added VALUE does a MagLev have over a wheeled train that makes it worth the high cost?

One of those puppies just broke the 500kmh barrier with passengers.

I believe that that was the maglev (see final paragraph)

They do, check out this link.
The japanese definately have the economy to do this, like has been mentioned. From the page:
A landmark for Maglev occurred in 1990 when it gained the status of a nationally-funded project.

The Japanese use supercondutors to reach these speeds.

That's why the German alternative is considered economically much more efficient.

And even this alternative has turned out to be less efficient than high speed trains of normal rails.

The Japanese made a couple of mistakes however. First their track switching technology is cumbersome. They literally move concrete barriers around to shove the train onto another track. Secondly, they didn't design their magnets correctly and so have had problems maintaining them. Those problems aside, the Japanese have done a first rate implementation job.

The Germans, in an attempt to circumvent the Powell and Danby patents and cut costs, chose a conventional electromagnet approach for their maglev solution. Powell and Danby had considered eletromagnets and rejected them due to inherent limitations. First, electromagnets aren't anywhere as strong as superconducting magnets so the gap between vehicle and track is much smaller. Secondly, a power loss would be catastrophic. Thirdly, the way the Germans have approached maglev using magnets to attract each other, requires active controls. The intra-magnet gap has to be maintained to very close tolerances otherwise the train gets pulled into the track or falls away from the track if it veers too far. The tolerance problem will be especially acute in seismically active locations like China and California where tracks will drift slightly on a daily basis.

Powell and Danby have kept working at maglev despite paltry American support. Their website describes several design changes to their original idea. They've designed all electronic switching equipment that makes dynamic track switching feasible. That's advantagous on a heavily traveled track that's being shared by express and local trains. They've also re-arranged their track to a monorail cum flatbed design to support dynamic switching.

Their website describes a variety of uses for maglev. Among them is a trans-continental vacuum tube that enables coast to coast travel in under an hour. The vacuum is necessary because as the train speed increases, the majority of power that's required to move the train is spent moving air out of the way. An evacuated tube makes it possible to move a train across the continent using the equivalent of 20 gallons of gas.

One hundred and fifty years ago, Lincoln authorized the construction of a transcontinental railroad. At the time, it was considered technologically impossible given the chasms and mountains that had to be crossed. Lincoln initiated the transcontinental railroad in the middle of the civil war. Part of his motivation was to demonstrate that though engaged in war, the United States was great enough to concurrently tackle a monumental engineering task.

Fifty years later, we built the Panama Canal, another technological impossibility. Finally 50 years ago, Eisenhower authorized the interstate highway system and the St. Lawrence Seaway.

Fifty years have passed since this country last undertook a major infrastructure challenge. Whether our generation steps up to the plate and makes a significant contribution to the infrastructure as our parents, grandparents and great-grandparents have done remains to be seen.

For a more in-depth explanation of the Yamanashi Test Line Maglev trains' technology check out this link. Quite interesting stuff!

Ah, that's why they are going to build maglevs especially in Europe and Japan Because they are more expensive to build and maintain.

In fact, they are building them because current trains have NOT enough capacity. Especially the highly congested route between Tokyo and Osaka. (Probably the first "real" route sporting maglev.)

AFAIK, the construction costs are indeed higher. Nonetheless, the conventional successors of highspeed trains as the Shinkansen, the TGV or the ICE are mostly limited to roughly 300km/h operational speed. The problem is at very high speed the wheels and the track are strained to the extreme, which leads to wear and tear of the same.
A future successors of the Shinkansen (Linear Chuo Shinkansen ) will be based on maglev, as the supposed successor of the ICE-line the Transrapid.
The Linear Chuo Shinkansen is supposed to have an operational speed of 500km/h. The current Transrapid built in China has an operational speed of 300km/h
Not to mention the better acceleration and lower noise rate, delivered by these solutions.
The Transrapid reaches 300km/h after 5km from a standing start and breaks certainly as fast as it accelerates.

Furthermore, the energy consumption of current maglev based trains are about 40% lower than their conventional counterparts.

Linear Chuo Express (Japanese)

• History of past experimental models
  
• Movie (AVI/QuickTime) of highspeed cross running(?) (relative speed of 966Km/h)

Railway Technical Research Institute (English) - Lots of cool pics!

Now, as far as I know from reading these sites, they are nowhere near the point of rolling out production level Maglev. I remember reading somewhere that superconducting magnets are still too costly to produce and operate. They are still working out all these details.

I just got a gut feeling that both German and Chinese are rushing ahead for such a premature technology. This technology is definitely way to go as future transportation system, but not quite yet ready...