What you are weighing is the 99% of night drivers who are not drunk and will now be able to see you because of the light, versus the 1% of them who do happen to be legally drunk, and the fractional percentage of those people who might be so drunk as to cause an accident, and the fractional percentage of that subset who might be susceptible to the "ooh look flashing light, I'll steer right at it" phenomena

I'll take my chances with the light.