Road Signs

I'm finally back from NY and home in Chicago. The road trip wasn't too bad today. But I have basically spent 4 of the last 6 days in a car. The thing that kept bothering me was the Deer Warning signs. I understand that there are deer everywhere. I think nowadays you always need to be on the lookout for Bambi. But what I don't understand is how these Deer Warning signs are placed.

Example 1: On a stretch of road in NY we pass a Deer Warning sign that says Next 7 miles. What I don't understand is the following?

1. What about the stretch of road preceding these 7 miles?

2. What about the stretch of road following the 7 miles?

Example 2: Still in Central NY, we pass a Deer Warning sign that says next 5 miles. We pass it and then 1/2 mile later we see another Deer Warning sign that says next 2 miles.

1. Do deer really not cross in that 1/2 mile of road?

2. Wouldn't it have been easier to make a sign that said next 7 1/2 miles instead of two separate signs? No wonder our country is in debt.

Example 3: Again in NY, we pass a Deer Warning sign that says next 1 1/2 miles. In that 1 1/2 miles there is another Deer Warning sign that says next 2 miles.

1. Why would you have a sign within a sign range when the second sign is greater than the first sign?

2. If this was a result of entering a new township or village, does each town or village get to arbitrarily decide where to tell motorists that deer are going to cross?

Any enlightenment would be helpful.