The Green Line has long been called "the rail line to nowhere" — a route that goes from Norwalk to Redondo Beach and to within about 2.5 miles of Los Angeles International Airport's passenger terminals, which can be reached by a roughly 15-minute shuttle ride.
Now, 16 years after the Green Line opened, there is a push to expand rail service in the area. But to the dismay of some, getting the rail line into the airport still remains an uphill battle.
At least 20 airports across the nation have rail access, according to the American Public Transportation Assn., including those in Chicago and New York. LAX is the nation's third-busiest airport and the sixth-busiest in the world, and travelers have long wondered why L.A. has no airport rail link.
"It doesn't make sense," said Thomas Sanchez, a transportation researcher with the Brookings Institution. "It's a big investment. It yields lots of benefits just in terms of moving people. If you're taking people to a concentrated employment hub as well as a transportation hub, it's the most logical thing to use."
Planners initially hoped the Green Line, which opened in 1995, would make it to the airport. There is even an unfinished spur of the line near the stop at Imperial Highway that teases northward toward LAX.
But they ran out of money before the extension could be built. Linking the Green Line to LAX also faced hurdles from the Federal Aviation Administration, which worried the line could create a hazard to air navigation, interfere with electronic or visual aids, or obstruct aircraft approach and departure paths.
The new focus on rail in the area is being spurred by plans to build the Crenshaw Line, which would run through Southwest L.A. and Inglewood and intersect with the Green Line. This project would extend the Green Line to the corner of Century and Aviation boulevards, about 1.5 miles from the airport.
The key question is how to close the remaining gap. Planners say they are studying all options, including building a light-rail line directly into the central terminus.
But many transportation experts say that scenario is unlikely because of the high cost and a variety of logistical and air safety issues. Placing the last leg of the Green Line underground would swell the price tag, because tunneling is much more expensive than laying track above ground.
Ian Gregor, a spokesman for the FAA, said running the rail line above ground by the south runway protection zone would raise some of the same issues that challenged the Green Line from extending into the airport in the 1990s. Those issues include whether the overhead catenary wires would interfere with runway operations and whether the rail electronics would cause problems for air traffic control.
Planners and transportation experts say the most likely scenario appears to involve a "people mover" that would take passengers from the rail station at Aviation and Century and into and around the central terminus.
It's unclear exactly what the people mover would look like. Atlanta's airport has one of the more successful such systems, a subway-like tram line with seven stops throughout the airport. Denver's airport adopted a similar system.
Michael Molina, a deputy executive director for Los Angeles World Airports, said officials were committed to bringing passengers from the rail station into LAX but were still unsure what plans to pursue. He said the concept of a people mover was being studied as part of the airport's specific plan and expected staff to have recommendations by next year.
Some transit experts say such a system could cost about $600 million.
Currently, the proposed rail extension has $200 million budgeted for the airport link. The funds are from expected revenue from Measure R, the half-cent sales tax for transportation projects that voters approved in 2008.
A recent planning memo to the Metro board of directors says the extension could begin operating anywhere from 2015 to 2028. The memo noted that the airport could provide extra funding to make the link happen.
"There is actually some money behind this," said Metro project manager Roderick Diaz. "There is the LAX master plan, which theoretically has some implementation thrust as well. There is a very real connection being made at Aviation/Century.... There is a lot of attention."
Improved rail service to the airport could not come soon enough for some passengers.
Earlier this month, Chicago native Jon Franklin hopped on the Blue Line at 7th Street/Metro Center downtown with two bags, a black winter coat and a scrap of paper scribbled with directions to LAX, where he was catching a noon flight home.
As passengers waited for their stop, someone tried to sell candy bars and single cigarettes, three for a dollar. About 45 minutes later, Franklin switched to the Green Line in Willowbrook and wondered whether he would make his flight.
"I guessed it would take about an hour, but I was off," he said, looking at the time, and talking about how in Chicago, he needed to take only one train home from the airport.
Franklin, 30, got off at the stop closest to the airport, checked the time again, and pondered where the shuttle was before it finally appeared and passengers hurried aboard. Fifteen minutes later he was at the terminal, but it was too late. He had narrowly missed his flight.