Why are there white markers (small signs) at the sides of a rural interstates?

Question

I noticed that there are white markers at the side of every rural interstate. It's not like it's going to prevent crashes. Why are they there?

Answer 1

There to HELP u in a crash. they have some that will have numbers in on them, then 15 blank ones, then a number. so like 234 then 15 blankes then 235. if u get in a crash, u can count how many blank ones to the nerrest mile then u can call 911 and say "im at mile marker 235 and 3/16" and they can find u much faster. or u can report like a car crash or a dead dear on the road and its exact location. its easer than saying,,"um.. like 3 miles from a stop sign" lol

Answer 2

Mile markers and they also have the County you are in listed.

Answer 3

The white reflectors on the side of the road?  They do prevent crashes, by making it obvious where the side of the road is.  If it is dark and rainy, paint on the road isn't always obvious.  

If you are talking about the ones with numbers on them, they are tiny mile markers.