By GENE JOHNSONAssociated Press Writer SEATTLE (AP) – For years, critics of Sound Transit have derided its plan to build a light rail line that stops just short of Seattle-Tacoma International Airport as a “train to nowhere.” The agency announced Tuesday it hopes to answer that complaint by completing a 1.7-mile extension in 2009, just a few months after the initial stretch from downtown Seattle to South 154th Street in Tukwila opens. It should take riders 35 minutes to reach the airport from Seattle. “I expect the headlines now to read: ‘Central Link is a train to somewhere,”’ Sound Transit board chairman John Ladenburg said. The extension will cost about $225 million, on top of the $2.4 billion pricetag for the line from downtown Seattle. The money will come from existing sources, primarily sales and motor vehicle excise taxes collected locally, Sound Transit spokesman Geoff Patrick said. Plans call for the extension to run from South 154th Street, where the initial segment will stop, to the fourth level of the airport parking garage. The new station will have an elevated walkway to International Boulevard and a pedestrian connection to the airport’s ticket counters. Until the extension is complete, riders will take buses from 154th Street to the airport. There are some hurdles, however. The plan is contingent on the state coming up with $25 million to $30 million to add a lane to State Route 518, which drivers use as they leave the airport. The extra lane is needed to prevent traffic from backing up on the airport drive loop, which will be expanded once ramps near the parking garage are destroyed to make way for the new rail station. “We see it as a critical link for the airport,” Michael Cheyne, Sea-Tac’s director of planning, said. The Port of Seattle, Sound Transit and the city of SeaTac have been working on the plan since early last year. “This plan will speed the departure and arrival of the thousands of travelers and employees who come and go from the airport every day and will spur economic development in the local area,” SeaTac Mayor Frank Hansen said.