Lane Support Systems can assist and warn you when you unintentionally leave the road lane or when you change lane without indication.
Sometimes a moment of inattention is enough to make your vehicle stray from its lane. The systems monitor the position of the vehicle in the road lane and while Lane Departure Warning warns you if the car unintentionally wanders from the path, Lane Keeping Support helps you correct the course of your car.
LANE DEPARTURE WARNING
On a long highway journeys, a driver may unintentionally drift towards the line identifying the edge of the lane. Very often, the driver will be unaware that the car is in a potentially dangerous situation until the situation is critical: the wheels of the car may be on the grass or gravel at the side of the road or, in extreme cases, the car may find itself in the path of oncoming traffic. This sudden, late realisation by the driver may prompt a panic response: the driver loses control of the car and a crash is often the result.
Several manufacturers have developed technologies which warn the driver when the car is getting close to a lane marking. Different systems use different warnings: some give an audible signal while others use a vibrating steering wheel to simulate the feeling of the car running over a ‘rumble strip’. The intention is simply to make the driver aware that the car is in danger of crossing the line. Some systems need a line only on one side of the vehicle while other systems rely on having a distinct marking on either side.
Manufacturers take great care to ensure that the signal does not irritate drivers unnecessarily and stay in control at all times. Most systems operate only at highway speeds and suppress the warning signal if the direction indicator is used.
A camera is normally situated behind the rear view mirror at the top of the windscreen. The images of this camera are continuously analysed by a computer to identify the lane markings and, in some cases, an unmarked road edge. At the same time, the driver’s steering input is monitored as well as the speed and trajectory of the vehicle. These parameters are combined to determine whether or not the car is about to depart the lane of travel.
Lane departure warning systems rely on distinct lane markings: their effectiveness if reduced if lines cannot be clearly distinguished such as in heavy rain or fog, or if the road markings are obscured by mud or snow. In such cases, an indication is given to the driver that the system is unable to assist´.
LANE KEEP ASSSIT
Lane-Keep Assist systems address similar accident situations to lane departure warning. However, whereas warning systems rely on the driver to take corrective action, Lane Keep Assist also proactively steers the car back into the lane. When the car is close to a marking, the system gently steers the car away from the line until it is safely within the lane. The system can steer the car either by applying gentle braking to one wheel or, in the case of electric steering systems, by applying a direct steering input.
Drivers however should not rely on Lane Keep Assist to do their driving for them. Some systems deactivate if they sense that the driver is no longer steering the vehicle. In any case, the systems can take corrective action only if the lane marking is being approached very gradually: more rapid departures cannot (and should not) be corrected by Lane Keep Assist systems.