There are lots of reasons for this and some of them are: being more visible to oncoming traffic (cars and bikes), being able to react to their actions and to more easily avoid abduction.
Be especially careful with this when crossing where a driver an turn right on a red light. They most often look left, not right, before making this turn. How many of us have done the “left hand on the hood, jump and spin” move?!!
It is important to be aware of your surroundings; people, pets, cars, and be able to take evasive action if necessary.
A good habit is to let someone know when you leave, what route you are taking and when you expect to be back. We put considerable trust in our cell phones, which is OK, and we need to prepare “just in case” our battery dies, or we drop our phone and it doesn’t work, or we splay on the sidewalk and our phone flies into the road and is run over by the oncoming car!! You get the idea, let’s avoid the worst case scenario.
Reflective clothing, lights, blinkers and/or carry glow sticks from dusk on. We can see the cars and it is easy to assume they can see us. Let’s make sure they do!