I need everything to be close to my home.
Typically, a box turtle lives its adult life of 60, 80 or more years in an area a few hundred feet wide and long. Adult box turtles have virtually no predators. Automobiles (and to a smaller extent, lawnmowers and tractors) are their greatest killers. So, if their small acreage is kept free from roads and lawns, many turtles will live longer than you will.
Diversity is the key to keeping turtles at home. As much as possible, each element should be mature and self-sustaining. Size does matter--but character matters more. A young forty-acre woods is good. A mature forest of only twenty acres, with native understory species, may be better. Twenty acres of mature forest with a sunny, moist clearing at the center is better still, and so on. Think big, but remember to think. (That forty-acre woods needs a clearing!) A little of everything--except people--is best.
Still, turtles have urges to move. They tend to travel from one part of their small range to another by season or by weather. Some old, wise, energetic turtles (and some young, foolish, romantic turtles) may move up to 2,000 feet each spring, and return along the same path before fall arrives. If that path crosses a road or lawn, the turtle is playing Russian roulette with a Honda.
These long tours actually may be an effort to find a particular habitat feature. It is up to you to provide a variety of needed habitat closer together along that path. If you do, the turtle may be able to shorten its journey. By avoiding a single road crossing, you eventually will have saved the animal's life.
For more box turtle stewardship guidelines, see Habitat from Humanity.