Can you get a ride from a co-worker or someone else? I’m not sure how you go about getting a written request for an accommodation, but I’d think it’d have to come from an eye doctor who could verify that your vision is diminished in the dark. Then you need to make note of the fact that your department of motor vehicles may well be notified in the event that this is in your medical record, and you might get a driver’s license that restricts your driving in some way as a result. If you can get a ride from a co-worker or a relative in order to make your later shifts, that might work for now at least. Is there a possibility of using public transit for some portion of the trip? For the most part, I’m just asking because I think those will be your employer’s questions as well. At this time of year, with so little daylight normally, it can be tough to schedule every one of your shifts within that window, I’ll bet.