Car Advice

How good is Subaru’s EyeSight AEB system?

Can Autonomous Emergency Braking systems like Subaru’s EyeSight help you avoid animals, like kangaroos?

ON THE BACK of well-publicised media reports about Transport Minister Stephen Culligan’s roo hit, we thought we’d explain more about Subaru’s EyeSight system. Because as has been revealed with that incident, the driver intervened by touching the brake pedal, thus reducing the input from the braking system. So, let’s get serious for a moment.

Subaru’s EyeSight is an autonomous emergency braking (AEB) system. Like all such systems, it is a driver aid and not a driver replacement. AEB systems attempts to detect potential collisions – they then warn the driver, and if the driver takes no action, the AEB system tries to slow or stop the car. The use of the words here is deliberate – “attempts to”, and “tries to slow”. This is because no AEB system is 100% effective, and indeed they only work within fairly narrow parameters. This is why the TAC’s AEB campaign is so misleading.

I’ve done quite a few tests of EyeSight starting from the earliest models in 2012. It’s hard to test, because you need to trust the vehicle to stop and that goes against every instinct you have as you approach an obstacle, even if it’s just a dummy animal. If you touch the brakes then the car assumes you have control and the AEB function is disabled. This was the driver error in the car the Minister was travelling in which resulted in the ‘roo strike’, and it just happened to be the one the TV cameras ran with. It was a one-off event during a day of test runs.

So when can you trust Subaru’s EyeSight, or any other AEB system? Simple – never. If it kicks in consider it a bonus, if it doesn’t, well then you were prepared. You get best results from EyeSight when:

  • Car speed is less than 40km/h (preferably under 30km/h);
  • The object in front is at least small-child sized, doesn’t move and doesn’t just suddenly jump in front;
  • The terrain is level and dry bitumen;
  • The car is in good condition, particularly brakes and tyres; and
  • There are no issues with sensing, for example fog, direct into sunlight, dirt on windscreen, and so on.

When that happens the car will sense the object, warn via lights and sound, and if you take no action slam the brakes on hard. It works well, but never rely on it (are you getting the message here?). Basically, you can’t simply drive around oblivious to what’s going on and rely on the car to brake for you…

The EyeSight system is a bit unusual in that it uses twin stereo cameras. Most of the rest use radar or LIDAR (light-based radar). The best systems would use every possible sensor, but there are pros/cons to the camera system.  The cons are that cameras can be thrown off by lighting problems, as everyone who has taken a photo knows. That’s not a problem with radar-based systems to any great degree. The pro is that the cameras can be very good at recognising things, as we’re seeing now with the likes of face detection in smartphones, and indeed the latest-generation EyeSight system is able to detect brake lights and road signs. Radar is hopeless at that.

We’ve got more on the issue of AEB in our full explainer you can read here. Finally, one point which Senator Ricky Muir likes to make and we agree 100 per-cent – these electronic aids still require a level of car knowledge which simply isn’t being taught. Until we have totally driverless cars we will have an uncomfortable halfway house where the electronic help, some of the time, in some ways, and it’ll be up to the driver to best manage their car and its systems while remaining in control at all times.  The best way to do that is driver education, and you can read two opposing views on that here and here.

Oh, and can you rely on AEB to avoid roos?  Absolutely, definitely not.  The only known way to prevent roo strike is to travel outside the hours of dawn and dusk when they are most active. 

The driverless car is coming, but it’s not here yet.  You’re still responsible.


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Robert Pepper

Robert Pepper