There is no doubt that without Southwest air fares would be a lot higher. My October trip to Las Vegas was just booked at $181 from Nashville which is 3 hours from my house. The cheapest flight out of Knoxville was $455 for the same time. Knoxville no longer has any low fare carriers. When Air Tran was here we could fly to Florida for $59 one way. Now it is a lot more.