I can't help thinking that the focus on really high speed train travel is hovering outside the realm of practicality. Such immense speed invariably attracts technical problems with disastrous potential. Imagine a cow or some roos on such a track. Would a fence on both sides of the track be realistic ?
My take is if someone wants too travel really fast then take an aeroplane. Planes can by-pass floods, animals etc. at no extra cost. For what it's worth I believe in slower, more reliable trains for passenger & freight service. Ideally in my book is a Mono Rail.

inndividual,

On a monorail, how would you clear a major breakdown of a train?

Individual, the VFT only makes any sense at all after the airlines have
been priced out because of fuel costs.
The airlines have been fiddling with biofuels.
Certainly at present fuel prices biofuels are not a goer, but as fuel
prices rise they might become viable.
Catch22, first using biofuels to produce biofuels is a cost problem
and biofuels still have a poor energy return on energy invested.
In a rationing regime, if it reaches that, aviation fuels may be banned.

However in an economy where airlines have been priced out there will
not be either the credit or taxes available to build the VFT.

The best we can do is to start yesterday on rebuilding the mainline
track to higher standards and to straighten them out to increase speed
to around 200km/hr standard.
Electrification could be done at the same time.

However while governments are still pouring money into roads I just
cannot see any chance that the upgrade will be done in time.

is Mise,
Fix it like any breakdown is fixed, you repair it. Repairing a Monorail is no different to any other piece of mechanics. At least a Monorail would suffer a hell of a lot less breakdowns from cars crossing the rails, from trees, from flooding, from whatever else happens on present rail lines. Plus it wouldn' hold up any other traffic.
In the long run I'd bet that a Monorail would be a winner. But you can't wait for the long run can you, you want your returns now not in a few years. It's that kind of impatience that's gradually costing us a good future infrastructure. You don't use investors for such a project if they can't carry it for at least five years. Why do you think the wealthiest families are so wealthy ? Because they're not after a quick buck like most backyard investors.

Just came across this article on the US VFT proposals.

http://www.nytimes.com/2014/08/07/us/delays-persist-for-us-high-speed-rail.html

They are having the same sort of problems that we would encounter.

individual,

If it is a monorail then it is either suspended or is running on top of the single rail with gyroscopic compensation.
If the former then the train must be towed back to the nearest siding if it is the latter then it has fallen off the track and would pose no problem; but for safety the whole track would have to have continuous rest strips along the whole route so that in the event of a power failure the train can't fall over.

There would be a substantial problem towing such a train back to a siding as it would have no stabilizers.
The only way to keep it upright would be to fit wheels to run on the rest strips, in effect a train running on three rails.

Why are there no freight monorails or any long monorails (this includes all the elevated railways that pose as monorails).