Now, intelligent car doors!

Imagine you opening your car door suddenly into the path of an oncoming motorcyclist; but the door clams up and a potential mishap is averted.

Cut to reality. Automobile engineers in Germany claim to have designed "intelligent" doors which react to potential impacts on roads, facilitating vehicles to get equipped with the potential to make observations as well as the driver.

A team from vehicle manufacturer BMW and Technical University of Munich has come up with 'haptic' -- a technology which gives tactile feedback -- doors that could cut both road injuries and repair bills, the New Scientist reported.

The current prototype looks like a normal car door, but an extra metal bar runs through its centre and connects to the car's frame between the hinges. In normal mode, the bar moves freely and doesn't affect the door's movement.

However, if sensors detect a nearby obstacle at the same time as an accelerometer detects an attempt to open the door, the door's swing is restricted by linear motor attached to the bar, according to the engineers.

To pass on more information to the user, the amount of door resistance is in proportion to the proximity of an object -- for example, you might swing a door halfway open without problems before it gets stiffer as it nears a lamp post.

"The current prototype uses ultrasonic sensors to spot dangers, but because they have a limited field of view, the next version will use cameras that can span 180°," Michael Strolz, who led the team, was quoted as saying.

"Then we will be able to sense the complete workspace of the door and detect people walking by the car or cycling towards it. The technology is mature enough that a car factory could be pumping it out in cars within a year," he added.

Reactions from 16 volunteers who tried the new door at BMW's Munich research centre have been encouraging, according to the team which has reported its findings at a seminar in Salt Lake City.