Toyota Motor Corp.'s Lexus division unveils the world's first rear pre-crash safety system on the new LS 460 at the Geneva auto show today.

By using a millimeter-wave radar system in the LS' rear bumper, the pre-crash system can activate the front-seat pre-crash headrests to move forward and upward if it determines an approaching vehicle is about to hit from behind.

The pre-crash system on the LS has been upgraded with stereo cameras, as well as an improved millimeter-wave radar to detect pedestrians, something the previous version could not do, Lexus says.

Furthermore, a camera is mounted on the steering column, as well as an image-processing computer, to detect whether the driver's face is forward.

If not facing forward, the driver is alerted sooner that the possibility of a collision is high. If the driver does not brake, the pre-crash brakes are activated to reduce vehicle speed.

Other safety features on the new LS 460 include front, side and curtain shield airbags, as well as Supplemental Restraint System knee airbags for both front passengers; an SRS twin-chamber airbag for the front passenger seat, which already is available on the '06 Lexus IS series; and a Lane Keeping Assist System. (See related story: Lexus Airbag Saving Face)

The '07 Lexus LS 460 will go on sale worldwide this fall, powered by a new 4.6L V-8 engine mated to an 8-speed automatic transmission. A hybrid-electric variant is due the following year. It will be shown at the upcoming New York auto show. (See related story: New Lexus LS Unveiled in Detroit)