Position racks in upper and lower thirds of oven; preheat to 375 degrees F. Line 2 large rimmed baking sheets with parchment paper.
Cut carrots and parsnips into ½-inch-thick slices on a diagonal, then cut into half moons. Cut beets and onion into ½-inch-thick wedges. Cut sweet potato into ¾-inch cubes. You should have about 12 cups raw vegetables.
Toss the vegetables with oil, vinegar, herbs, salt and pepper in a large bowl until well coated. Divide between the prepared baking sheets, spreading into a single layer.
Roast the vegetables, rotating the baking sheets top to bottom halfway through, until fork-tender, 30 to 40 minutes.
