Airlines have raced to find the fastest way to board a plane for years, and with good reason. Less time spent on boarding can translate into cash.

Studies have shown that an airline can save up to US$30 per flight for every minute cut from boarding.

An astrophysicist thinks he has now found the most efficient way to get passengers on board.

Dr. Jason Steffen, an astrophysicist at Fermi National Laboratory in Illinois, suggests that loading passengers by alternating rows, starting from the back of the plane, is quickest. When loading people in a row, travelers in window seats file in first, then middle seats, followed by aisle seats.

Steffen's way emerged as the fastest when pitted against four other boarding methods, the BBC reported.

Producer of TV show "This v That" Jon Hotchkiss recruited 72 luggage-carrying volunteers to test out five ways of boarding a Boeing 757 mock-up.

It took the volunteers three minutes and 36 seconds to board according to the Steffen method, the BBC said.

The "Wilma method," which has all window seat passengers boarding first, followed by middle seats, and ending with aisle seat passengers, took four minutes and 13 seconds.

Loading the plane took four minutes and 44 seconds if passengers are boarded by random.

The slowest methods were ones that most air travelers are familiar with.

The "block" approach, which seats passengers in descending groups of rows, took six minutes and 54 seconds. "Back to front" boarding, which loads travelers one by one in descending rows, didn't fare much better -- six minutes and 11 seconds.

Dr. Steffen's method was fastest because it eradicated the gridlock created when passengers try to use the same physical space at the same time, the BBC said.

But Are Airlines Listening?

Earlier this year, American Airlines started boarding passengers by random.

The new "randomized" boarding procedure was introduced on U.S. and Canada flights in May this year, and has since been expanded to international flights.

Once the first class and executive class passengers have boarded, coach passengers are boarded in the order they checked in, regardless of where their seat is.

The new procedure supposedly saves four to five minutes of boarding time from the current 20 to 25 minutes, the airline told Wall Street Journal.

Cattle class passengers wishing to board early have to pay US$10 for the privilege.

The new policy is not without its detractors, though. Some flight attendants pointed out that randomized boarding caused "complete chaos" in the cabin, according to the Los Angeles Times.

Others wonder whether the policy change is just another way for AA to sneak in extra fares for things that travelers normally take for granted, such as imposing fees for blankets and pillows.

Despite the stirrings of change, major carriers are in no hurry to follow suit.

A spokesman from Qantas said they have no plans to change their current "block" approach. "Most of our recent research and innovation has focused on the land side of the airport, which we identified as the real point of pain for our customers," the spokesman added.

Cathay Pacific and Japan Airlines, two carriers who also board passengers from back to front, said they have no plans to change their boarding procedures.