Bob Gardner wrote:

Before I had a car with automatic daytime running lights (05 Corolla), I
routinely turned on my headlights during the day. DRLs are mandatory in
Canada and many other countries. Motorcyclists keep their headlights on
during the day to enhance visibility. The "camouflage" theory is faulty.

Because of its higher latitude, Canada (and Scandinavia etc) has a lot of hours
of twilight during many months when the sun is low but headlights are not
required since it is daytime. This is one of the reasons why DRLs became
popular and then mandatory in Canada. Unfortunately, in North America, it is
legally acceptable to use high beam lights (somewhat dimmed) for DRLs even
though they are aimed up. This causes a lot of glare and can be
distracting/harmful to the vision of oncoming drivers. Most GM cars use this
type of setup, and Saturn cars are the worst offenders, I believe. Then again
many drivers leave fog lights (with their diffused beam that goes EVERYWHERE,
not in an aimed beam like headlights) on all the time at night even though it is
clear as a desert sky. North America car light standards are poor.