The collapse of public support for the monorail in November 2005 created a mass transit void in West Seattle and Ballard that is likely to continue for years.

Sound Transit is currently building a 19-mile-long light rail system from the University District south to Sea-Tac Airport. The three-county agency already built a light rail line connecting the Tacoma Dome to downtown Tacoma.

Next fall, Sound Transit will put before voters a 40-mile light rail expansion proposal that would take about 20 years to complete. If approved by voters, Sound Transit's Link light rail system would extend northward from the University District to Northgate and Lynnwood. It would continue east from downtown Seattle along I-90 to Mercer Island, Bellevue and Overlake. The expansion project also would go south from the airport to Federal Way and the Port of Tacoma.

None of the new light-rail service would come to Ballard or West Seattle. Until a year and a half ago, planners expected the western side of Seattle would be served by the monorail.

Besides light rail, Sound Transit also operates the heavy gauge Sounder commuter trains, which connect Seattle, Tacoma and Everett during weekday morning and evening commutes. Although the Sounder passes by Ballard, there are no stops there. The Sounder comes nowhere near West Seattle.

West Seattle benefits from Sound Transit's regional express bus service. The blue, green and white buses connect West Seattle to Burien, Sea-Tac Airport and Bellevue. There is no Sound Transit regional express bus service in Ballard.

King County Councilmembers Dow Constantine and Larry Phillips recently announced they've convinced Sound Transit to study the feasibility of expanding Link light rail service to West Seattle and Ballard. Money to pay for such a study would be included in the $16.5 billion roads-and-transit ballot measure that voters will decide on next autumn.

"This study will give us the knowledge to make light rail to West Seattle, North Highline and Burien feasible," said Constantine, who represents West Seattle, Burien and Vashon Island on the County Council.

Phillips, who represents Ballard, Magnolia, Capitol Hill and downtown Seattle, said buses are fine but light rail could carry more passengers faster.

"Ballard and West Seattle are dense, pro-transit communities who face an uncertain mobility future," Phillips said. "Sound Transit has an opportunity to look at integrating the western part of Seattle into the regional light rail system."

Such a study could include examining the feasibility of using part of the monorail project's planned "Green Line" route through West Seattle, said Chris Arkills, a legislative aide to Constantine. The study likely would look beyond the Green Line's terminus at Morgan Junction and continue south to Burien, Southcenter and even Renton, he said.

A variety of possible routes would be part of such a study along with cost comparisons, ridership potential, environmental tradeoffs and other issues. A future question could be whether to send a light rail line to the Fauntleroy Ferry Terminal from Morgan Junction or head southeast to White Center and Ambaum Boulevard.

Ballard's future light rail line could run east to the University District, where passengers could change trains to go north or south.

A vital part of any proposal to bring light rail to West Seattle or Ballard would have to include a plan for how to pay for such an expansion, said Jeff Patrick, spokesman for Sound Transit. And since the transit agency was created by the Washington Legislature in the first place, legislators also must approve any financing plan to pay for expansion, he said.

The Sound Transit board of directors is scheduled this week to finalize the list of projects and studies to be included in next fall's ballot measure.

Tim St. Clair can be reached at 932-0300 or timstc@robinsonnews.com