Under certain circumstances, it can be very difficult to distinguish a cyclist (or pedestrian), especially if it's in a "busy" environment. A good example is a well lit urban road within a shopping district, especially during the Christmas holidays where you have light pollution from storefronts and roadside decorations.

On quieter urban settings, I always prefer to have steady AND flashing lights on both ends of the bicycle. The flashing light should get the attention of the driver and the steady (bright) light will be a constant point of reference which helps the driver judge the distance (in theory).

I posted the video above because in dangerous situations, I've noticed that it helps to have a larger frontal profile through weaving, but I do understand that in your case it would have been difficult because of the icy road conditions.