Assisted Driving Gradings Explained
Since 2018, Euro NCAP has evaluated various Highway Assist systems offered by car manufacturers. Highway Assist helps the driver to maintain a steady speed, to keep a safe distance from the car in front and to keep the vehicle in the centre of the lane by combining (intelligent) Adaptive Cruise Control (ACC) with Lane Centering (LC). However, the driver always needs to be responsible and engaged behind the wheel, and the assisted system is there to do just that – assist. Euro NCAP tests the capability of each system to support the driver under normal traffic driving conditions and investigates how the system ensures that the driver remains engaged in the driving task.
System Grading
From 2020 onwards, Euro NCAP has issued separate Highway Assist gradings, based on dedicated test and assessment protocols. The grading is divided into two main areas:
- Assistance Competence, based on the balance between Driver Engagement and Vehicle Assistance, and
- Safety Backup.
The balancing of Driver Engagement and Vehicle Assistance captures the principle that good performance in one area is not helpful unless it is accompanied by good performance in the other. In other words: high levels of assistance must be matched with good driver oversight to avoid overreliance of the driver and increased crash risk. The Safety Backup evaluation consists of crash avoidance testing and rates the vehicle's ability to mitigate a crash in case the assistance system is unable to prevent a collision. The total score is the sum of Assistance Competence and Safety Backup and is divided into the following gradings: ENTRY-MODERATE-GOOD-VERY GOOD.
What do the gradings mean?
An Entry vehicle assistance system typically provides assistance in the less challenging scenarios and comprises only a basic ACC and Lane Centering system, with no additional features. Or, the system’s performance in Assistance Competence is highly unbalanced between Driver Engagement and Vehicle Assistance. The safety back-up is limited.
ACC and Lane Centering generally perform well in the less challenging scenarios, but the system has a better performing safety back-up compared to Entry-graded vehicles. Unbalanced vehicles with a good safety back-up also end up in this category.
Both ACC and Lane Centering perform well in most situations and the system keeps the driver engaged. Good systems also contain some extra features to provide the driver more assistance and provide a good safety back-up.
Vehicles graded Very Good are state-of-the-art ACC and Lane Centering systems with additional functions to support the driver and keep him engaged. These vehicles also provide a high-level safety back-up in challenging scenarios, utilizing the extended sensor set these vehicles are equipped with.
Introduced in 2018. Upgraded in 2020