alt Hacker NewsI don't know reindeer but white tailed deer, possums, raccoons, rabbits, and nocturnal birds don't care how fast you're going. As someone else mentioned, you can be stopped and they'll run into your vehicle.
None of these animals instincts prepared them for the cacophony and lightshow of transportation. Everyone doing 15mph might solve 90% though, but I'll let that be your running platform.
But lower speeds do make crashes a lot less deadly. Probably also less probable, as people have more time to react