If you took Delta Air Lines Flight 5073 from New York to Atlanta last year, the chances were very good you were late. From June through November, it arrived behind schedule 94 percent of the time, by an average of more than an hour, according to federal data.

But you'd be hard-pressed to find that information before booking a flight.

Because the flight is operated by Delta's regional carrier Comair, the delays did not count against Delta's on-time record. And Delta's online reservation system does not provide customers with delay statistics.

Growing airline delays combined with incidents that stranded passengers have prompted a new push in Congress to force airlines to disclose to travelers how often flights arrive late.

That aims to help people avoid chronically delayed flights and comes after passengers were stranded for up to 10 hours this winter on grounded planes in New York and Texas.

Proposed as part of a "passenger bill of rights," the law would enable travelers to find out before booking a flight online whether it is chronically delayed. The legislation defines chronically delayed as arriving at least 30 minutes late more than 40 percent of the time during three consecutive months. The Transportation Department inspector general and some travel experts consider the disclosure a critical step in giving passengers better information about delays.

"The public is flying blind," said Paul Ruden, a lawyer for the American Society of Travel Agents. "If you knew a flight was delayed 15 percent of the time and another one was delayed 60 percent of the time, that might have a major effect on which flight you choose."

Kate Hanni, who became an advocate for the passenger bill of rights after being stuck on an American Airlines flight in December, called regularly delayed flights "bait and switch tactics."

"People just have no idea how many flights are chronically delayed, what flights they are, and how to find out that information," Hanni said.

Three carriers — United, U.S. Airways and Alaska — already provide on-time statistics on their Web sites. Federal law requires airlines to disclose delay information if customers ask for it on the telephone. The industry is considering providing the information on all airlines' Web sites, said David Castelveter, spokesman for the Air Transport Association.

Most airline officials bristle at making reporting mandatory. Chronically delayed flights represent a tiny fraction of all flights, and are overwhelmingly due to congestion at a few key airports, they said. Disclosure would do little to unclog those hubs, they add.

"The customer doesn't really care what happened six months ago or six weeks ago or what the odds are," said Roger Cohen, president of the Regional Airline Association. "What they care about is whether it's going to arrive that day."

Airlines pay attention to delayed flights because they cost money and anger passengers, said Kevin Healy, a vice president at AirTran Airways. "We have a system built in that proactively looks for problem flights, and then we fix them," Healy said. "You don't wait until they get on the (government's) list."

Sometimes competition prompts airlines to sacrifice on-time performance. The delays of Delta Flight 5073 coincided with the carrier's decision to add flights last year at New York's Kennedy International Airport to compete against JetBlue.

Chronically delayed flights represent a small fraction of the millions of airline flights each year, from less than 1 percent to 3 percent according to federal measures. The Department of Transportation counted 950 instances in which a flight was delayed at least 15 minutes 80 percent of the time during a month. That amounted to more than 21,000 delays.