DALLAS (AP) -- Passenger traffic has been rising this spring on Southwest Airlines -- yet a key revenue figure for the nation's fourth biggest carrier has been stuck in neutral.
Airlines haven't been able to raise prices as often or as fast as they did a couple years ago. Dallas-based Southwest could indicate how that affects its business when it reports first-quarter financial results on Thursday.
United Continental Holdings Inc. and JetBlue Airways Corp. report earnings the same day.
Southwest, which also owns AirTran Airways, reported that traffic on the two carriers rose a healthy 4 percent in March compared with a year earlier. But a key measure of revenue for every seat flown one mile was flat.