Imagine you're on the highway. You glance into the cab of the 18-wheeler next to you — and there's no driver. That day might be getting closer.

Automaker Daimler unveiled a truck last week that drives itself, called the Freightliner Inspiration. But the truck is not yet entirely autonomous.

The North American International Auto show begins this week in Detroit, a preview of the most important car technology on the horizon. One of the stars of the show this year is the Ford F-150, a truck that's been the best-selling vehicle in the U.S. for decades. And it's by far Ford's most important model.

On Monday, the company unveiled a radically new more fuel-efficient redesign of the F-150 — featuring a lighter-weight aluminum body.

Aluminum's Advantages