good question. I lake ride at night sometimes and it is much easier to see land forms w/o headlights, especially with any snow coming down.
Best analogy is driving a boat at night. Maybe figure out the best way to do this....turn off the headlights and have navigation lights come on, now that would be interesting to see tooling down the lake.
Why would you ever ride at night with out a headlight? Even in the day your asking for a fatal accident! Just last week we had 2 guys that where good friends run into each other at night and are died because of it. Remember lights are there for you to see and for others to see you!
not all the time. more to be able to switch off the headlights so that you can pick out land forms to key on then turn on and go. It doesn't take long to get bearings via known land forms...quick off and then on at very slow speed or stopped. We do that right now by shutting down.