Heat oven to 425°F. Spray 15x10x1-inch baking pan with nonstick cooking spray. In large bowl, combine carrots, potatoes and onion. Add oil, basil, thyme, garlic salt and pepper; mix well. Spread evenly in sprayed pan. Bake at 425°F. for 20 minutes.
Remove vegetables from oven. Add green beans; toss to mix.
Return to oven; bake an additional 20 to 25 minutes or until vegetables are tender, stirring once.