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Comment by Svip | Hacker News Reader

This is why the TGV has no signals. Instead it uses a radio communication system. If no radio signal is received within a time frame, the train will warn the driver, and eventually stop. If a train has to perform an emergency stop, all other trains behind it are informed via the same system. If the driver does not react, the train will stop itself.

There is a reason why the TGV has seen no accidents since its launch in 1981.

As for a car, yeah, it's mostly a gimmick. Still incredible engineering, though.

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While it may be safe, no accidents since launch might be a bit of an overstatement: https://en.m.wikipedia.org/wiki/List_of_TGV_accidents

OK, you're right. I should have clarified my statement; there have been no serious incidents on LGV tracks while in service. Level crossing accidents and collisions take place outside the LGV tracks, when the TGV run on standard railway tracks. Only one high speed derailment caused fatalities, and that was during a test run.

Thanks I'd never seen this. So there have been quite a few incidents, but the takeway at the top seems to be there has been no fatality “at high-speed”. I guess that's something to be proud of, but that's still far from a perfect track record.

The most important reason why the TGV has not had any accidents is actually a really simple one: it only runs on very high quality rails with large turn radii and excellent maintenance of the railbed.

And even that is not entirely true. The TGV can only run this fast because it runs on tracks where only the TGV is allowed.

The rail bed is even not that great, that's why only some ICEs are allowed on TGV routes, because they need a special deflector which is more robust to tolerate the stones which are thrown up in the air when the train drives over it.

I think they took this in consideration when they designed the latest iteration of the ICE.

I'm not sure that's entirely correct.

If https://en.wikipedia.org/wiki/High-speed_rail_in_France is to be believed, the high speed lines for TGV are primarily but not exclusively used for TGV:

"LGVs are reserved primarily for TGVs. One reason for this is that line capacity is sharply reduced when trains of differing speeds are mixed, ..." "Some stretches of less-used LGV are routinely mixed-traffic, such as the Tours branch ..." "Outside France, LGV-type lines often carry non-TGV intercity traffic, often as a requirement of the initial funding commitments."

I'm also not so sure about the quality of the rail bed:

"Track alignment is more precise than on normal railway lines, and ballast is in a deeper-than-normal profile, resulting in increased load-bearing capacity and track stability. "

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