Mobileye's Lane Departure Warning system

What It Is: Drivers are getting more help with staying safe on the road.

Cutting-edge automotive-safety technology gives drivers night vision, or sends alerts if the car moves too close to other objects or drifts outside its lane. Some systems can also make sure the driver signals properly.

How to Get It: Mobileye's Advanced Warning System-4000 uses a windshield-mounted camera to monitor cars and driving lanes in front of the car; the system sounds warnings if it determines there isn't enough space between you and the car ahead; if a forward collision is about to occur; or if the car moves outside of its lane without using a turn signal.

The 2008 BMW 5 Series uses a Mobileye lane-departure warning system that makes the steering wheel vibrate when it senses a dangerous situation. The 5 Series and the 7 Series also offer optional night vision, in which an infrared camera scans up to 1,000 feet ahead and projects high-contrast black-and-white images onto a center-console LCD screen.
Cadillac's 2008 STS and 2008 DTS and the 2008 Buick Lucerne use Mobileye's lane-departure warning technology as well as a Side Blind Alert System, in which the side mirror lights up and a chime sounds if sensors gauge an object in the blind zone. When the 2007 Infiniti G35's laser-guided cruise control detects the car is nearing the vehicle ahead too quickly, the car automatically slows to a safe-braking distance.

Upside: If the car complains when you turn without using a signal, you may find yourself more diligent about signaling. And systems that gauge and maintain safe-braking distances may keep bumper riders -- and fender benders -- in check.

Downside: All those chimes and chirps can become nuisances and cause drivers to turn them off -- defeating the purpose of a warning system. Also, the systems are reliant on clear visuals, so they are of little help during heavy fog or snow. (The AWS-4000 works in inclement weather, however, during low visibility, the system will turn itself off after notifying the driver.)

Cost: The BMW 5 Series' lane-departure warning system is a $500 option; night vision is $2,200 on the 5 Series and 7 Series. The driver-awareness package for the 2008 Cadillac STS includes lane-departure and blind-side alerts for $1,290; pricing not yet set for the 2008 Cadillac DTS and the 2008 Buick Lucerne. Intelligent cruise control is available on the Infiniti G35 sedan only ($1,100) but only if you purchase the premium ($2,350) and navigation option packages ($2,100). The Mobileye AWS-4000 is available as an aftermarket product at Hurley's Auto Audio, a Washington, D.C.-area dealer. Installation runs around $1,800 and is usually completed within one to two hours; call (703) 790-8744 for more info.