I am looking for suggestions in planning a route from central Texas to Portland, Me. I would like to avoid large cities and too many toll roads. Our schedule allows us 5 days to get there. Thanks
"I prefer I78 from just north of Harrisburg to 287 to 87 to 84 or 90."
Nothing wrong with the route above, I would have mentioned it myself but you said you wanted to avoid tolls. Both I-87 (NY Thruway) and I-90 (Mass Pike) are toll roads.
There are many ways to get to your destination, none of them are free, empty of traffic or without grades and summer construction.