Driving with headlights on does NOT use more fuel - that's an old-wives tale.

The lights are supplied with power from the battery, not direct by the alternator. The alternator is turning 100% of the time, independent of the electrical load on the vehicle electrical system. A normal regulator in automotive applications doesn't have a clutch of any kind. Increased electrical load doesn't equate to increased friction or force req'd to turn the alternator.

Daytime running-lights were introduced in Sweden in the '70s, IIRC. They are now pretty much universal throughout Europe, and the Jeep I rented in Canada this summer had them.