Driver Assistance Technologies
Overview
In 2019, 36,096 people died in motor vehicle crashes. Research shows that the vast number of vehicle crashes are tied to human error. New driver assistance technologies hold the potential to reduce the number of crashes and save thousands of lives a year. We here at NHTSA are committed to making our roads safer for everyone. Learn more about our work to help bring these technologies to market–and what you need to know about them when buying your next vehicle.
Technology Saves Lives
Driver assistance technologies not only keep drivers and passengers safe, but they keep other drivers and pedestrians safe too. When shopping for a new or used vehicle, you may notice that different manufacturers have different names for driver assistance technologies. NHTSA is helping consumers break through the confusion with information about how these technologies work, as well as safety-related performance data. Some systems are designed to warn you if you’re at risk of a crash, while others are designed to take action to actively avoid a crash. It’s important to understand the difference. Be sure to review your vehicle’s owner’s manual for more information on that particular vehicle’s technology and safety features – after all, they can’t save lives if they aren’t being used properly. From blind spot detection to braking systems, find the latest in driver assistance technologies below.
Tech Overview
Detects a potential collision and provides a warning to the driver.
This is a NHTSA recommended safety technology that meets the agency's performance specifications.
Applies brakes automatically when forward collision is imminent.
This is a NHTSA recommended safety technology that meets the agency's performance specifications.
Detects pedestrian crossing in front of the vehicle and warns driver; applies brakes automatically if collision is imminent.
Automatically switches your vehicle’s headlights to the lower beam when an oncoming vehicle approaches and back to the higher beam when it passes.
Detects a potential rear collision and automatically engages the brakes if a crash is imminent
Provides the driver with a clear view directly behind the vehicle.
Watch a video that demonstrates and explains this driver assistance technology.
This is a NHTSA recommended safety technology that meets the agency's performance specifications.
Warns the driver of potential rear collisions that may be outside the view of the backup camera.
Monitors lane markings and provides warning if the driver unintentionally crosses out of their lane.
This is a NHTSA recommended safety technology that meets the agency's performance specifications.
Automatically and gently steers vehicle back into its lane if the driver unintentionally drifts over lane markings.
Warns of a vehicle in the driver’s blind spot.
Provides continual steering to keep vehicle centered in its lane.
Automatically accelerates and brakes the vehicle with the flow of traffic and keeps vehicle between lane markings—even in curves.
Maintains vehicle’s lane position and following distance by automatically braking and accelerating as needed.
Automatically adjusts the vehicle’s speed to keep a pre-set distance from the vehicle in front of it.
Tech In Your Car
NHTSA promotes the safe use and manufacture of vehicle equipment
Through safety standards and consumer information, NHTSA demonstrates its commitment to reducing crashes and saving lives in the United States. NHTSA works diligently to inform consumers about the types of driver assistance technologies that are available and which technologies we recommend.
We now know that driver assistance technologies are the right path toward safer roads. We will work diligently to bring you updated information whenever there is a new breakthrough in this technology.
Search for more resources
Title | Type | Audience | Date | Language |
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gm_receipt_notice_03152019 PDF, 356.78 KB |
Document | Advocacy Groups | 03/15/2019 | |
nuro_petition_03152019 PDF, 11.85 MB |
Document | Advocacy Groups | 03/15/2019 | |
nuro_receipt_notice_03152019 PDF, 294.58 KB |
Document | Federal Government | 03/15/2019 | |
Functional Safety Assessment of a Generic, Conventional, Hydraulic Braking System with Antilock Brakes, Traction Control, and Electronic Stability Control Appendices PDF, 5.21 MB |
Document | 03/12/2019 | ||
Functional Safety Assessment of a Generic Conventional Hydraulic Braking (CHB) System with Antilock Braking System (ABS), Traction Control System (TCS), and Electronic Stability Control (ESC) Features PDF, 1.56 MB |
Document | 08/07/2018 | ||
Lane Assist
Lane Departure
A lane departure warning (LDW) system is an advanced safety technology that alerts drivers when they unintentionally drift out of their lanes without a turn signal. It’s important to note that LDW systems do not take full control of the vehicle or keep the driver from operating it.

LDW systems provide a valuable safety benefit, and can help keep you and your passengers safe from crashes such as:
- Striking a car in an adjoining lane, which could either involve “sideswiping” a vehicle traveling in the same direction or hitting a vehicle traveling in the opposite direction; and
- A rollover, which often occurs when a vehicle leaves the road.
Yes. LDW systems that meet NHTSA’s performance specifications are indicated with an icon on NHTSA’s 5-Star Safety Ratings, under Recommended Safety Technology. We recommend that you look for this technology when shopping for a vehicle. LDW systems are an option on many new cars, SUVs, and trucks. To find out if LDW is available in the vehicle you’re interested in buying, visit NHTSA’s 5-Star Safety Ratings and search for 2011 vehicles and newer.
Lane Keeping
Using lane monitoring technology, lane keeping support (LKS) is an emerging safety technology that prevents drivers from unintentionally drifting out of their lanes.
LKS systems use information provided by sensors in a lane departure warning system (LDW) system to determine whether a vehicle is about to move out of its lane of travel. If so, LKS activates by correcting the steering, braking or accelerating one or more of the wheels, or a combination of both, resulting in the vehicle returning to its intended lane of travel.

LKS systems provide a valuable safety benefit, and can help keep you and your passengers safe from crashes such as:
- Striking a car in an adjoining lane, which could either involve “sideswiping” a vehicle traveling in the same direction or hitting a vehicle traveling in the opposite direction; and
- A rollover, which often occurs when a vehicle leaves the road.
Backup Camera
A rearview video system (RVS), also known as a backup camera, is a safety technology that helps prevent back-over crashes and protect our most vulnerable people—children and senior citizens. By providing an image of the area behind the vehicle, backup cameras help drivers see behind the vehicle.

Blind Spot Detection
Blind spot detection (BSD) systems warn drivers with an audio or visual warning if there are vehicles in adjacent lanes that the driver may not see. The alert helps facilitate safe lane changes.

Automatic Emergency Braking
Automatic emergency braking (AEB) systems detect an impending forward crash with another vehicle in time to avoid or mitigate the crash. These systems first alert the driver to take corrective action and supplement the driver’s braking to avoid the crash. If the driver does not respond, the AEB system may automatically apply the brakes to assist in preventing or reducing the severity of a crash. NHTSA believes these technologies represent the next wave of potentially significant advances in vehicle safety. The AEB systems engage dynamic brake support (DBS) or crash imminent braking (CIB) to potentially save lives and reduce moderate and less severe rear-end crashes that are common on our roadways.
Dynamic Brake Support and Crash Imminent Braking
If the driver brakes, but not hard enough to avoid the crash, DBS automatically supplements the driver’s braking in an effort to avoid the crash. If the driver does not take any action to avoid the crash, CIB automatically applies the vehicle’s brakes to slow or stop the car, avoiding the crash or reducing its severity.
In 2015, 33.4 percent of all police-reported crashes involved a rear-end collision with another vehicle as the first harmful event in the crash. NHTSA believes that advanced crash avoidance and mitigation technologies like DIB and CBS systems could help in this area. NHTSA’s extensive research on this technology and on relevant performance measures showed that a number of AEB systems currently available in the marketplace are capable of avoiding or reducing the severity of rear-end crashes in certain situations.

Yes. CIB and DBS systems that meet NHTSA’s performance specifications are indicated with an icon on NHTSA’s 5-Star Safety Ratings, under Recommended Safety Technology. We recommend that you look for this technology when shopping for a vehicle. CIB and DBS systems are an option on many new cars, SUVs, and trucks. To find out if CIB and DBS are available in the vehicle you’re interested in buying, visit NHTSA’s 5-Star Safety Ratings and search for 2011 vehicles and newer.
Pedestrian Automatic Emergency Braking
A pedestrian automatic emergency braking (PAEB) system—also known as frontal pedestrian impact mitigation braking—is an emerging safety technology that provides automatic braking for vehicles when pedestrians are in front of the vehicle and the driver has not acted to avoid a crash.

Many pedestrian crashes occur when a pedestrian is crossing the street in front of the vehicle. Four common pedestrian crash scenarios include when the vehicle is:
- Heading straight and a pedestrian is crossing the road;
- Turning right and a pedestrian is crossing the road;
- Turning left and a pedestrian is crossing the road; and
- Heading straight and a pedestrian is walking along or against traffic.
NHTSA has not set performance specifications for this feature, but NHTSA recognizes PAEB as a promising technology that may be added to the 5-Star Safety Ratings list of recommended technologies in the future. PAEB systems are an option on many new cars, SUVs and trucks and can help you avoid a crash. To find out if PAEB is available in the vehicle you’re interested in buying, check the manufacturer’s website.
Forward Collision
A forward collision warning (FCW) system is an advanced safety technology that monitors a vehicle’s speed, the speed of the vehicle in front of it, and the distance between the vehicles. If vehicles get too close due to the speed of the rear vehicle, the FCW system will warn that driver of an impending crash. It’s important to note that FCW systems do not take full control of the vehicle or keep the driver from operating it.

Yes. FCW systems that meet NHTSA’s performance specifications are indicated with an icon on NHTSA’s 5-Star Safety Ratings, under Recommended Safety Technology. We recommend that you look for this technology when shopping for a vehicle. FCW systems are an option on many new cars, SUVs and trucks. To find out if FCW is available in the vehicle you’re interested in buying, visit NHTSA’s 5-Star Safety Ratings and search for 2011 vehicles and newer.
911 Notification
An automatic crash notification (ACN) system is an emerging safety technology designed to notify emergency responders that a crash has occurred and provide its location.
Automated Vehicles for Safety
Learn about the technology of tomorrow.