Interesting article, but for those of us interested in railroad signal
technology, the article offers few technical details. I suspect that
the author didn't really have any background in this area, nor would I
expect him to have such background. The article doesn't really make
clear that for a high-speed line you need in-cab signal display, as
the train operator cannot reliably see lineside signals at high speeds.

From the very beginning it appeared to me that the Chinese had not
understood the basic concept of railroad signaling being "fail safe."
Though that term has often been twisted into other meanings, at its
core, it means that if something goes wrong, the system will still
take the safe action, if necessary stopping trains.

One of the sad facts is that there were at least three perfectly good
proven high-speed rail signal systems available: The Japanese, the
French, and the German. Each of the systems is independent of the
type of rolling stock it is installed in. For example when Spain
built its AVE high-speed system, it chose French TGV-based rolling
stock, but opted for the German LZB signal system.

I know the most about the German LZB system, whose long German name
translates something like "The line influences the trains." (Or, the
line controls the trains.)

That system is based on a sophisticated floating block concept that
relies on continuous communication between the train and the dispatching
center's computer through a continuous antenna cable that runs between
the rails. Any loss of communication in the signal system stops the
trains. German locomotive engineers affectionatly call the system "The
Third Man." (The first generation of German ICE trains had two seats in
the cab: one for the engineer, the other for an instrutor or observer.
Hence, the computer was "The Third Man."

When I got a cab ride on an ICE train many years ago, we went from a
conventional line to a dedicated high-speed line, and the engineer
proclaimed, "Now the Third Man is driving."

On the high-speed lines, the engineers still monitor system operations
and can, if necessary, override the automated system. But, then, operation
is only possible at much lower speeds.

-- Ernest