Copyright Goodheart-Willcox Co., Inc. 510 Section 5 Electrical and Electronic Systems Technology driver’s blind spot. This system may also be referred to as a blind spot monitoring system. Rear Cross Traffic Alerts A rear cross traffic alert (RCTA) uses sensors in the corners of the rear bumper to detect vehicles approaching from the side and rear of the vehicle while it is traveling in reverse. If the driver does not stop the vehicle and an object is detected in the vehicle’s path, the system will engage rear auto braking to stop the vehicle. These systems work best when you are backing straight out of a space or driveway. The vehicle’s speed must be less than 5 mph (8 kph). Many vehicles also have this feature on the front end of the car. Pedestrian Detection System A pedestrian detection system (PDS) will alert the driver and/or automatically brake if there is a pedestrian in the vehicle’s path, Figure 38‑11. These systems will only apply the brakes when driving at lower speeds, up to about 35 mph (56 kph). A PDS can detect people in the roadways up to about 20′ (7 m) in front of the vehicle. Some vehicles with electric steering assist will also turn the vehicle away from the pedestrians if it cannot stop soon enough to avoid a collision. Road Sign Recognition A road sign recognition (RSR) system uses forward- facing cameras to detect road signs. Initially, the system was limited to recognizing speed limit signs. It would alert the driver of the current speed limit on the driver’s display screen. This system may be referred to as a traffic-sign recognition system (TRS). Lane-Keeping Assistance A lane-keeping assistance system controls steering to keep the vehicle within the driving lane. It uses a camera that is usually built into the back of the rear view mir- ror. The camera scans the road for lane markings. If the driver drifts toward a line without using a turn signal, a warning chime sounds. The system may also steer the vehicle away from the line to center the vehicle in the lane. Systems may vibrate the seat or steering wheel to alert the driver. Some vehicles use multiple cameras to scan the road for markings. This system may also be referred to as a lane-centering assist system. See Figure 38‑12. Road-Departure Assist System A road-departure assist system uses some of the same technology as a lane-keeping system but it does more than keep the vehicle in its lane. If the system detects that a vehicle is about to leave the road, it cuts back the throttle and applies the brakes. A road-departure assist system may be designed to take over if the lane-keeping assist system is insufficient. This system may be called a road-departure mitigation system (RDM) or a lane- departure assist system. Driver Monitoring System A driver monitoring system (DMS) uses a camera in the dash to monitor the driver’s alertness. The camera is aimed at the driver’s face. The system recognizes the driver and monitors the driver’s alertness or vigilance. The system alerts the driver when signs of drowsiness or distraction are detected. Some systems are used to monitor and record driving habits, such as speeding and erratic driving. Driver monitoring systems work in conjunction with other ADAS to help ensure safety. For example, if the DMS determines that a driver has fallen asleep or is oth- erwise unresponsive, systems such as the lane keep and emergency auto braking will slow and stop the vehicle. This system may also be referred to as driver drowsiness detection, driver alert, or a driver focus system. Adaptive Light Control Automatic high beam assist systems dim or brighten the headlights depending on oncoming traffic and headlights. Some systems can sense the vehicle ahead and will adjust the lights so they are not glaring in the car’s rear window. Rear view mirror vision Left side mirror visible area Right side area Light and/or symbol Blind spot area rumruay/Shutterstock.com Figure 38-10. Blind spot monitoring warns the driver if someone is approaching blind spots right behind or beside his or her car in another lane. Lights in the rear view or side mirrors may flash and an audible sound may be emitted to warn the driver. Akarat Phasura/Shutterstock.com Figure 38-11. Pedestrian detection systems typically use cameras, but some use a combination of cameras and radar sensors. A PDS uses information from sensors and cameras to determine if a pedes- trian is in danger of being hit by the vehicle.