As cars keep getting smarter, automation is taking many tricky tasks -- from parallel parking to backing up -- out of drivers' hands.

Now, a University of Toronto Engineering study is underscoring the importance of drivers keeping their eyes on the road -- even when they are in an automated vehicle (AV).

Using an AV driving simulator and eye-tracking equipment, Professor Birsen Donmez and her team studied two types of in-vehicle displays and their effects on the driving behaviours of 48 participants.

The findings, published recently in the journal Accident Analysis & Prevention, revealed that drivers can become over-reliant on AV technology. This was especially true with a type of in-vehicle display the team coined as takeover request and automation capability (TORAC).

A "takeover request" asks the driver to take vehicle control when automation is not able to handle a situation; "automation capability" indicates how close to that limit the automation is.

"Drivers find themselves in situations where, although they are not actively driving, they are still part of the driving task -- they must be monitoring the vehicle and step in if the vehicle fails," says Donmez.