WOW. Thank you all for the great resonses. I just want to say how helpfull everyone has been and how impressed I am.

After speeking with the utility, they quoted the first 150 feet free and $13/ foot after that for overhead. I think I can convince the customer to go three poles (450 feet)That brings me under 500 feet which also saves on trenching costs.

Also, I already have been awarded the project. The service is going in as a change order.

This seems to be a good question and perhaps some engineer should come up with a calculation that should be in the code. Just a thought.