UK team flags importance of "transition time" for driverless cars

Simulations run by a team at Southampton University showed a range of ‘control transition times’ for participants to resume control of their car. The researchers believe their findings will be important for system designers when considering the lead time needed to take control of a vehicle and suggest the focus shouldn’t just be on the average time needed for a person to successfully switch, but rather on the range of resumption times.  Results are published in Human Factors.

Engineers Professor Neville Stanton and Alexander Eriksson reportedly found that, under non-critical conditions, drivers needed between 1.9 and 25.7 seconds to take control from automation.  Such a large range reflects a variety of driver behaviour and environmental conditions.
The authors observed 26 men and women (aged between 20 and 52) engaged in simulated driving at 70mph, with and without a potentially distracting non-driving secondary task.

They recorded response times as the drivers took over or relinquished control of the automated system. A takeover request was issued at random intervals ranging from 30 to 45 seconds during normal motorway-driving conditions. The authors found that drivers performing a secondary task, prior to a control transition, took longer to respond and posed a potential safety hazard.