Bring a large pot of water to a boil over high heat and salt it. Add the pasta and cook until al dente, according to the package directions, about 9-11 minutes. Drain and rinse with cool water.
Meanwhile, in a large bowl, whisk together the mayonnaise, sugar, honey, onion powder, pepper, and salt. Add the cooked pasta, carrots, relish, celery and green onions. Toss until the pasta is evenly coated with the dressing.
Cover and refrigerate until chilled, about 30 minutes or until ready to serve. Store leftovers, refrigerated in an airtight container for up to 4 days.