Parallel parking is one of the most feared tasks among teenagers learning to drive, and experienced drivers usually aren't too fond of it, either. The process requires you to keep an eye on what's happening to both the side and back of your vehicle as you try not to ding any other parked cars or run onto the curb – often while other vehicles on the road impatiently wait for you to finish the complicated maneuver.

Parking assist technologies make this arduous process much easier. These systems use sensors to identify whether a parking space can fit your vehicle, then take over steering during the process of parallel parking. The driver typically continues to control the processes of acceleration, braking, and controlling the direction of the vehicle to bring it snugly within the space.

Automakers warn that drivers should not rely entirely on these systems to park for them, since they may not work in all conditions and drivers still need to monitor the parking process. But a recent study by the Insurance Institute for Highway Safety found that these systems can significantly affect where a driver directs their attention when parallel parking.

In a collaboration with the Massachusetts Institute of Technology's AgeLab, IIHS had 31 volunteer drivers park a 2010 Lincoln MKS with Active Park Assist between two inflatable cars. Researchers observed where drivers looked when they approached the parking space and when they maneuvered the vehicle into the parking space.

The study sought to assess differences in driver attention when the parking assist system was activated and when it was not used. When not using the system, drivers were still able to use parking sensors and a rearview camera display mounted in the dashboard.

IIHS says it expected that drivers would look at the dashboard displays more when using the parking assist technology to maneuver into a parking space. However, they were surprised to find that drivers were more likely to look at the dashboard when approaching a parking space, even though they were in full control of the vehicle at this point.

On average, driver's spent 46 percent of their time looking at the dashboard display when approaching a parking space with the parking assist system activated. By comparison, their attention was directed at the dashboard for only 3 percent of the time when not using the system.

When the parking assist system was used, the typical driver approaching a parking space directed 31 percent of their attention in front of the vehicle, 9 percent to the rear, 5 percent to the right side, and 3 percent to the left side. Drivers without the system directed the majority of their attention—44 percent—to the front, followed by 25 percent to the right, 17 percent to the rear, and 4 percent to the side.

The differences were less pronounced during the parallel parking maneuvers. When the parallel parking system was activated, the average driver directed 35 percent of their attention to the rear of the car, 26 percent to the front, 15 percent to the dashboard, 14 percent to the right side, and 6 percent to the left side. Without the system, the average driver directed 35 percent to the front, 26 percent to the rear, 22 percent to the right, 8 percent to the left, and 3 percent to the dashboard.

IIHS notes that the parking assist system gives an audible chime and visual displays to alert a driver when a parking space is large enough for their vehicle. The study also says the drivers were unfamiliar with the system, and may have directed more attention to the system than drivers who frequently use it.

"Although we don't yet know how this change in glance behavior affects crash risk, manufacturers should consider how the design of new technologies can affect driver behavior in ways they might not intend," said David Kidd, lead author of the study and a senior research scientist at IIHS.