The research concerns driver distraction and what constitutes inattention while driving. Put another way, it seeks to determine how many times and for how long drivers should keep their eyes on the road to avoid causing an accident. The researchers believe that if that question can be answered, it might then be possible to detect inattention before bad things happen.

This theory of driver distraction comes from researchers at the Swedish National Road and Transport Research Institute. In their recent paper, “Minimum Required Attention: A Human-Centered Approach to Driver Inattention,” published in Human Factors journal, Katja Kircher and Christer Ahlstrom looked at the limitations of existing definitions of driver inattention and formulated MiRA, or “minimum required attention.” The journal is published by the Human Factors and Ergonomics Society, an association for human factors and ergonomics scientists, designers and engineers.

MiRA considers whether the driver — who after all is only one part of the larger traffic system — is maintaining situation awareness in the driving context. In other words, is the driver visually attending to and acting on the minimum amount of information from the environment necessary for safe driving?

MiRA weighs human factors such as a driver’s ability to adjust pace and location, balance goals such as efficiency and perceived risk, and use spare capacity (available reaction time) to attend to targets (traffic signals, pedestrians, etc.) that don’t pose a risk.

The researchers claim that many of the existing 50 or so definitions of driver distraction suffer from hindsight bias; that is, they identify distraction after the fact.

“With MiRA, the idea is to define the distraction criteria beforehand,” says Kircher. “Those criteria are based on areas in the driving environment in which certain information has to be sampled [viewed] a minimum number of times for safe operation of the vehicle.”

Kircher cites the the example. Driving on a curvy country road at a certain speed requires a certain minimum frequency of glances ahead to stay on the road. Research can investigate whether the drivers fulfill these requirements. In this way, they are able to check their behavior in real time instead of having to wait for a crash.

Kircher and Ahlstrom note that although MiRA is primarily a contribution to the theoretical discussion about driver distraction, it has the potential to be put into operation. With more study, they believe it might be possible to define prototypical driving situations and even determine whether a driver has fulfilled the requirements to optimize safety.

MiRA represents a new perspective on driver inattention and allows “a differentiation between issues related to the traffic system and the driver’s responsibility.”

As for where the research goes next, Kircher has a roadmap.

“Our goal now is to apply the theory systematically in our empirical work. Two projects on drivers’ and cyclists’ attention in an urban environment will provide the first opportunity to do so,” she said.