This handy travel data can help you plan your flights. Go to this Department of Transportation site for lots of great data on airport and airline delays, baggage claims, the number of passengers bumped by airline and more.
For example: the number of passengers denied boarding for Jan-Sep, 2009 was highest at United and US Air. If you’re looking to get bumped and score a voucher for the next flight, your luck will be better on these airlines.
Also note the percent of on-time arrivals at major U.S. airports. The percentage is almost always higher in the mornings, so plan your travels early in the day.