We have to have daytime running lights up here in Canada. In order to accomplish this (lower than normal light output of low beam headlights), the computer flickers the halogen bulbs at a very fast rate. This fools the eye into thinking that the light output is lower than normal. Halogen bulbs are able to flicker, HID bulbs cannot as fast as the halogens. Because of this, the flickering is more pronounced, that's probably why we don't have HIDs as an available option up here in Canada.
