In the Seattle area, for instance, under permanent DST sunrise could be as late as a few minutes before 9 AM. That puts a lot of people out traveling as much as 2 hours before sunrise.
Human society has historically been active after dark for social activities, like sitting around camp fires etc. Not so much early in the morning before the dark ends. We should adapt to what is natural for us humans, which is getting up around sunrise and possibly staying up after sunset. "Daylight Saving Time" is a move in the wrong direction. Let's at least stick to standard time.
Evening isn't as concentrated, because there is much more variation in when people come back than in when they go out.
If we only can do one of them in the light, morning probably makes the most sense because of it having more traffic volume and more traffic diversity.