The Sound Transit Board Thursday moved to kick off a public involvement process seeking input on new options that would modify last year’s mass transit expansion plan to form a faster and lower-cost package.

The major public involvement effort that Sound Transit launches in May will include meetings around the region as well as opportunities to comment online and by mail. In June and July the Board will consider the public priorities that are identified and whether to move forward with a 2008 measure.

The new options for a smaller package would lower the costs of last year’s Sound Transit 2 package by 41 percent to 49 percent. Sound Transit would complete these options within 12 years rather than 20 years. The options would cost 62 percent to 67 percent less than the total price tag for the roads and transit projects that together formed Proposition 1. The public is being asked to comment on whether the plan should be revised as proposed, or not.

The new 12-year options would achieve a 55 percent increase in the number of daily riders Sound Transit would serve in 2030. The new options center on a core set of investments funded by a sales tax increase of four-tenths of one percent (0.4 percent). Adding another one-tenth of one percent (for a total of 0.5 percent) would fund additional projects and services. The costs work out to an increase of about $55 (0.4 percent) or $69 (0.5 percent) a year for every adult, or either four or five cents for a $10 purchase.

The 12-year options would include funds for preliminary engineering, environmental review and early property purchase that would contribute to extending light rail to Everett and Tacoma in later phases.

Last year’s Sound Transit 2 plan called for building 50 miles of light rail over 20 years. If that plan were modified in favor of a 12-year approach, the new options propose that the expansions would include:

Link light rail — 18 to 23 miles of light rail expansions to the north, south and east, potentially serving communities including Bellevue, the Overlake area of Redmond, Mercer Island, Des Moines and Seattle’s northern University District, Roosevelt and Northgate areas. Connector light rail service would link Seattle’s International District, First Hill and Capitol Hill areas.

Sounder commuter rail — Increases of up to 90 percent in Sounder service between Tacoma and Seattle, potentially including 12 additional daily trips and platform extensions to allow longer trains.

ST Express regional bus — Service increases of 10 to 15 percent in key corridors, bus rapid transit service on State Route 520 and up to 20 miles of new arterial transit lanes.

Improved station access — Funding to increase access to transit facilities in Auburn, Edmonds, Everett, Kent, Lakewood, Lynnwood (including Ash Way and Mariner), Mukilteo, Puyallup, South Tacoma, Sumner, Tacoma and Tukwila. Projects will be tailored to the needs of each location and may include expanded parking; pedestrian improvements at or near stations; additional bus/transfer facilities for improved feeder service to stations; bicycle access and storage; and new and expanded drop-off areas to encourage ride-sharing.

Partnerships for expanded transit — Partnership funding for Eastside passenger rail on existing freight tracks; as well as for potential extensions of Tacoma Link light rail and projects in Bothell, Burien, Kirkland and Shoreline.

Public input collected in the first quarter of 2008 shows strong support for expanding the regional transit system, a perspective mirrored in a scientific telephone survey of 800 randomly selected residents. The results are available at soundtransit.org/future.

Sound Transit’s system of regional express buses, commuter rail and light rail currently carries about 50,000 riders each day, a number that will more than double following the 2009 opening of light rail service between downtown Seattle and Sea-Tac International Airport. Construction of that light rail line is moving forward on schedule and is now 85 percent complete.

Expansion of Link light rail between downtown and the University of Washington is slated to begin this year and be completed in 2016. University Link is projected to nearly triple the regional light rail system’s ridership to more than 114,000 a day by 2030. Last month, the Federal Transit Administration awarded the University Link project its highest rating for proposed transit projects in the nation, and $100 million for the project was included in the Bush administration’s proposed FY 2009 budget.