If there isn't enough daylight during part of the year to allow for both morning and evening commutes to be in the light, it probably makes more sense to give the light to the morning commute.
The morning commute is not only adults going to work. It's also kids heading to school, many on foot or bike.
The evening commute, on the other hand, is mostly adults coming home from work. School days are significantly shorter than adult work days, so the school kids are home by around 2-4 PM, before the evening commute starts.
Thus, if you only have enough daylight for one of them, you'll benefit more people by using that light for the morning commute.
The morning commute is not only adults going to work. It's also kids heading to school, many on foot or bike.
The evening commute, on the other hand, is mostly adults coming home from work. School days are significantly shorter than adult work days, so the school kids are home by around 2-4 PM, before the evening commute starts.
Thus, if you only have enough daylight for one of them, you'll benefit more people by using that light for the morning commute.