To clarify my position: My car is too old to have modern 'automatic dimming running lights', but I certainly would turn on some sort of headlights, parking lights... even flashing emergency lights... if conditions warrant (like seriously cloudy days, driving thru heavily wooded areas, valleys...etc.)
   I just seldom see the need in an urban area in bright daylight.

Those auto-dimming headlights 'may' be useful, but I actually never heard of them before this thread!