The boogey man loves to nibble on runners
It's also a lot more difficult for cars to see you but we can pretend that the boogey man is after us.
Reflective clothing and vests with flashing lights can help. Not sure where you live but if I don’t run in the morning (sometimes I fail to wake up early enough), I have to run in the dark at night otherwise it is just too hot!
Yes, it helps, but it's not the same as visibility during daylight hours. Fewer drunk drivers as well.
I can also do these things at night when it's not very safe to run.