Since the fall of 2000, design and budget problems with Seattle's original light rail transit (LRT) plan have prompted Sound Transit planners and decisionmakers to overhaul and reshape the phasing of LRT for the Seattle area. This has included creating a new starter line project.

The Seattle starter project has been reshaped into a 14-mile south Rainier Valley project at a cost of $2.1 billion, or about $150 million/mile. That's in year of expenditure (YOE) dollars, not 2002 dollars, so it includes inflationary increases into 2009 as well as such extra expenses as financing costs.

The revamped project – initially going south from downtown Seattle rather than north – includes significant amounts of elevated and underground construction (including overhaul of the Downtown Seattle Transit Tunnel). The project also encounters formidable terrain and civil works challenges because of the layout of the Puget Sound region.

A major objective for LRT in Seattle is to use the existing Downtown Seattle Transit Tunnel (DSTT), currently used by electric trolley and hybrid buses. Seattleites have expressed opposition to any elevated rail through their downtown; in addition, there is opposition to putting LRT in downtown streets. Furthermore, there is a desire to maximize the capacity of the DSTT by routing rail transit through it.

The plan is to initially route LRT trains from the south, Rainier Valley starter line, through the DSTT, sharing the ROW with some of the existing bus routes. To access the DSTT requires drilling approximately a mile of additional tunnel – a costly proposition which would also have to be included in any proposed monorail use of the DSTT (which no one has proposed). in addition to this, the South starter line includes extensive segments of elevated construction as well as some segments of surface construction, including brief sections in the median of major arterials. Much of the project resembles a subway-elevated line with some sections at grade.

While they're putting the South Starter Line on a fast track, Sound Transit planners are also trying to figure how to design a northward extension that will be affordable. The earlier, more expensive, plan involved a total 20-mile north-south route which included about 4 miles of tunnel running from the DSTT northeasterly under First Hill, then Capitol Hill, and then north in tunnel for a total of 4 miles, beneath the upscale Montlake neighborhood, and including a tunnel under Seattle's Ship Channel and into the University of Washington. in a series of public meetings, residents and business owners made it clear they would not settle for any elevated alignment of any kind through their neighborhood. in addition, any new elevated structure over the Ship Channel in that area would be vigorously opposed. The result is that the Seattle LRT project, as ultimately designed, will probably be the closest to an actual metro rail of virtually any LRT project in the country. Sound Transit is currently trying to find ways to scale the project to a level which can be financially supported, while proceeding to implement the South Starter Line project into the Rainier Valley.