France's state-run railway operator SNCF is working to develop driverless high-speed trains for its national rail system, effectively putting "drone trains" on the tracks.

The conductor-free TGVs (the French acronym for high speed trains) would bring self-driving tech to some of the fastest vehicles in the world, which regularly travel at speeds around 200 mph. The trains are projected to hit the tracks in 2019 for prototype testing, according to a FranceInfo report, and will only transport cargo to start. The TGVs could take on passengers by 2023 for routes between Paris and southeast France.

The SNCF trains wouldn't be fully autonomous and would instead be operated remotely, which helps to explain the "drone train" moniker. Conductors will still be onboard to take over in case of emergencies, and the trains will be staffed with a human crew as necessary.

The semi-autonomous TGVs will be outfitted with a suite of external sensors to detect obstacles on the track and initiate automatic braking if necessary, similar to safety systems currently found in many new cars with obstacle avoidance technology.

SNCF Deputy Managing Director Matthieu Chabanel told FranceInfo the trains aren't being developed to phase out conductors, comparing the tech to the systems used in airplanes. "In aircraft, you always have a driver, fortunately, but you have an automatic steering system," he said in a statement we roughly translated from the original French.

Autonomous train systems aren't that rare globally, but Chabanel claims this could be the first time self-driving is applied to high-speed systems. The Financial Times reported earlier this year that the main challenge stems from signaling and operating issues, which are still largely controlled by human drivers.