The corner of Pikeland and Charlestown is about 2 miles from my house but I'm usually traveling the other way so I haven't noticed the signs.  Are they specific about if it's going to be both roads or when this might occur?  Heading down Charlestown Rd toward 29 isn't the safest even now when going past Pikeland - I imagine having loose gravel isn't going to improve the situation.
 

What a pain!  Their disclaimer of "drive at own risk" doesn't work very well when you have to drive on that road to get home.

As for the repair - I worked in the IT department of a mid-sized direct personal auto insurance company for 10 years.  Many insurance companies will waive comprehensive coverage deductibles for windshield repairs.  They do this to encourage people to get small nicks repaired before it requires a windshield replacement.  You might want to check with your insurance company, it might be a matter of you paying $70 to SafeLite or a similar company and then your insurance company reimbursing you the full $70.

The general rule is that if a crack is smaller than a dollar bill it can be repaired.  Nicks and indents can usually be repaired as well.