Thanks for the ideas and help everyone. I have not contacted a lawyer
yet. This is our first house and well, not sure about all this.

I contacted the zoning dept. and he said "you surely had to know about
this when you bought the house". I said we did not and the builder
sold the land. Plans were then changed. Why would the builder pay for
all that extra concrete for the culdesac, if he planned on putting a
through street in.?

I was talking to the builder on some other issues and he confirmed that
this was supposed to remain a culdesac.