Preheat oven to 450°.
Remove and discard giblets and neck from chicken. Rinse chicken under cold water; pat dry. Trim excess fat. Lift wings up and over back; tuck under chicken. Combine 1 teaspoon each of rosemary, sage, and thyme, 1/4 teaspoon each of salt and pepper, 1 teaspoon oil, and minced garlic. Starting at neck cavity, loosen skin from breast and thighs by inserting fingers and gently pushing between skin and meat. Rub 1 1/2 teaspoons herb mixture in body cavity. Rub half of remaining herb mixture under skin. Rub remaining herb mixture and 2 teaspoons oil evenly over skin. Tie ends of legs together with twine. Place chicken, breast side up, on a rack coated with cooking spray in a shallow roasting pan.
Bake at 450° for 15 minutes.
Meanwhile, combine potatoes, carrots, onion, and halved garlic cloves in a large bowl. Add remaining rosemary, sage, thyme, salt, pepper, and remaining oil; toss gently to coat. Add vegetables to roasting pan. Bake an additional 15 minutes. Stir vegetables. Reduce oven temperature to 375°. Bake 40 minutes or until a thermometer inserted in chicken thigh registers 180°. Let stand 10 minutes. Discard skin. Serve chicken with vegetables.