assuming you're talking about daylight, it depends on your latitude and where your longitude falls in your timezone. with the current system, I drive to work in the dark and I drive home in the dark at different times of the year. I think it's more or less even for me, but maybe there's an optimal timing that minimizes everyone's commuting in the dark time. not that I feel particularly unsafe driving in the dark anyway, I only care if the sun is at an angle where I can't block it with my visor. either way, this seems like a marginal concern.
When I used to commute semi-regularly, part of it was along a highway (to use the term generously) that I swear was laid in a way to maximize the solar glare in some locations. One of those places is where it intersects with an interstate and semi-regularly you'd see cars that had been in accidents or the remnants of same at the side of the road.
