..include that light bulbs have a finite filiment life, so you will burn through about 2-4x as many light bulbs if you keep them on, depending on how much nightime driving you usually do, so that you will therefore not have the bulb functioning at night, when you really need it, that except for motorcycles, and except for countries extending above the arctic circle (eg. Canada, Sweden) there is little evidence that DRLs reduce accidents, and that you may not wish to draw undue attention to your car.

http://www.lightsout.org/story.html

In fact, Volvo thought enough of the idea that it included instructions on disabling the lights in the owner's manuals of all the 1997 SV90s sold in the USA (not Canada).

From page 20 of the 1997 SV90 owner's manual:

If the headlight switch is in position all lights will go out when starting switch is switched off.
With the headlight switch in position the parking lights will stay on (headlights off) with the daytime running light switch (A) in position .
The high beams can only be switched on if the headlight switch is in position .
Switch from high to low beams, and vice versa, by moving the turn signal switch lever on the left side of the steering column towards the steering wheel.
* Models equipped with daytime running lights: The low beams, tail lights, parking lights and license plate lights will come on automatically when the ignition is switched on.
Automatic daytime running lights
NOTE: The daytime running light function may only be disabled (turned off) in the U.S. - Canadian law mandates the use of daytime running lights.
Screw A in the illustration (available on U.S. models only) is used to control the automatic daytime running lights when the headlight switch is in position 0. To adjust, press in the screw with a small screwdriver and turn to one of the following positions:
Automatic daytime running lights

Automatic daytime running lights
** The daytime running lights will also function when the headlight switch is in position and switch A is in this position.
All lights off (daytime running light function disabled)

-bill d cat

'98 V70T5M, 106k mi, Mobil-1 always, DRLs off from mile #7, iPd Front stabilizer bar, Volvo rear bar, Volvo strut tower brace and Volvo skidplate, Valentine-1