The legislators who insisted the industry is dragging its feet would be the first to express horror when (not if) the system fails. Below is a preliminary report of a French collision involving a regional train striking the rear of a TGV train. And remember a few years ago the catastrophic collision on the Washington Metro resulting in 9 fatalities. It happens.

NTSB


FIRST DETAILS EMERGE OF SNCF/RFF INTERNAL INVESTIGATION INTO DENGUIN COLLISION
On 17 July a TER (regional service) collided with the rear of a TGV running at sight between
Pau and Dax. 40 people were injured, four seriously, two of whom are still in hospital. The
preliminary findings of the SNCF/RFF internal investigation indicate that the driver of the TER which collided with the TGV correctly observed the signals showing. The cause of the accident was a "wrong side failure" which occurred in the signal relay case, triggered by a highly exceptional combination of technical events, specifically faulty insulation on two wires at the end of the electric chain controlling the signal.
The report issued by the Safety Audits Division, which will be available from Saturday 26 July, will establish the causes of the insulation fault. The report will be published on the SNCF website, SNCF.com, and on the SNCF intranet.
Systematic checks have been initiated across the network, with immediate effect as of Friday 25 July.