A Southwest Airlines plane
Southwest Airlines Co. (NYSE: LUV) saw its February traffic jump 3.9 percent from a year earlier, marking the company's first traffic increase in three months. Reuters

Chicago O'Hare was just named the most dangerous airport in the U.S., according to Travel + Leisure magazine.

To find the most dangerous airports, Travel + Leisure examined the 35 busiest airports in the U.S. using Federal Aviation's Runway Safety Report for the last five years. Airports were then ranked based upon severity of collisions in a point system for an average year: 1 point per Category A (serious collision barely avoided) or .5 points for Category B (potential for collision).

In 2006, hundreds of passengers were saved by a pilot's quick thinking aboard a United Airlines 737 when an Atlas Air 747 rolled directly in its path on the O'Hare tarmac. The pilot turned, sharply avoiding collision by only 120ft.This was just one of 75 incidents reported at Chicago O'Hare over a five year time period.

O'Hare is now working on making the change to one of the safest airports. The runways at O'Hare will undergo a $6.6 billion modernization that plans to make the runways safer by 2014.

Ranking number two on this year's list is Cleveland Hopkins, with 45 runway incidents. Cleveland Hopkins was given a score of 5.38, barely behind Chicago O'Hare (5.65). Cleveland has updated their runway recently with a large extension, which will stop planes from crossing over runways.

Los Angeles International (LAX) also found itself in the top three with 60 reported runway incidents and a score of 4.41. In both 2006 and 2007, planes nearly collided when arriving and departing jets crossed paths. The FAA now holds a program at LAX to better train pilots, air control, and tarmac vehicles on best procedures for runway safety.

Although runway accidents can be caused by anything from weather to animals on the tarmac, most often pilots are to be blame.

Two-thirds of all runway incursions are caused by pilot deviation, Wes Timmons, FAA's recently retired director of runway safety, told Travel + Leisure.

Pilots of larger commercial jets are often not the offenders of deviation. Nearly 80% of accidents or near misses are caused by small private jets that are known to ignore air traffic instructions.

Places where you have a lot of [pilot] training activity or a large number of flight schools tend to see a larger number of runway incidents, Timmons told Travel + Leisure.

Top 15 Most Dangerous U.S. Airports

1. Chicago O'Hare

2. Cleveland Hopkins

3. Los Angeles International

4. San Francisco International

5. Honolulu International

6. Miami International

7. Fort Lauderdale Hollywood International

8. Phoenix Sky Harbor

9. Boston Logan

10. Dallas/Fort Worth

11. Chicago Midway

12. Denver International

13. Charlotte Douglas

14. Philadelphia International

15. Newark Liberty