What is an edge case in autonomous driving?

 

Edge cases are the unusual and unpredictable scenarios that are extremely rare on their own, but when added together make up the majority of the risk on our roads.

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We’re using traffic cameras, accident reports and insurance claims from around the world, along with stories submitted by the public, to compile the world’s largest library of edge case scenarios.

To date, AVs have mostly been trained to spot entire vehicles and pedestrians in well-lit and predictable environments. But the elephant in the room here could quite literally be the elephant on the road: how will an AV respond to unusual occurrences? While AV developers have trained their systems on a huge number of animal-related scenarios, there’s a nearly infinite number of ways that the real world can trip up AVs.

Training and retraining AVs using edge case simulations means testing them to their limits.

It involves teaching them to recognise high-risk events (a construction worker emerging from a manhole cover, pedestrians in dappled light, objects falling from a motorway bridge), and the predictors of potentially hazardous events too – like cars peeking out from behind other vehicles, pedestrians stepping out from behind buses in traffic, or cyclists running red lights concealed by other vehicles.

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Some edge cases are focused on context or nuance. An AV that can spot a bouncing ball needs to be able to recognise a frisbee or a boomerang too, and understand the different ways they move; signage for school zones will put an AV on high alert for children playing near the road, but the same vehicle will need to be wary of similar hazards in cul-de-sacs and suburban streets in the evenings, weekends, and during school holidays.

Early trials have shown that AV systems trained in this way can recognise high-risk events sooner, without a significant decrease in performance on low-risk events.

The library is used to train and retrain autonomous vehicles (AVs), as well as to develop examples of edge cases that haven’t occurred or been recorded yet.

Edge cases are organised into a knowledge graph, which provides a clearer understanding of the entire risk space. With this information, it’s even possible to extrapolate to other scenarios that haven’t been discovered or recorded yet – and then to use these to train and retrain until the AV can demonstrate the safest possible response.

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WHAT’S IN OUR EDGE CASE LIBRARY?

 

- Millions of CCTV near-misses and tight interactions drawn from hundreds of locations around the world
- Hundreds of thousands of accident reports from the US and Europe
- Thousands of AV-specific accidents
- Thousands of exclusive, human-reported accidents and near-misses
- Tens of trillions of scenarios, synthesized from dRISK's real life scenario data, guaranteed to evenly cover the entire manifold of risk

Millions of edge case scenarios.

And counting…

  • >200,000

    Collisions and high-risk near misses

  • >2,000

    Stories from the public

  • >60,000

    Weather scenarios

  • >10,000

    Animal or other non-vehicular, non-pedestrian scenarios

  • >140,000

    Scenarios involving other road users