Apr. 2--Thirty years ago, visionaries drew lines on a map of the Portland area. Today, those lines whoosh with speeding light-rail trains that every year ferry millions of people.

Now, it's time for the next 30 years.

That task -- guiding the next generation of mass transit -- is the lofty aim of planners laying out the region's future. They envision scattered hubs of activity connected to other hubs. And if given a mass transit boost, some of those could blossom into vibrant destinations, where future residents live and work.

How about a line from Portland to Tigard, or beyond to Sherwood? Why not connect Lake Oswego to Oregon City? And what about some small spurs off the existing system -- say to Forest Grove or Troutdale?

All are on the table but not for long. Routes that are included in the next three months in Metro's High Capacity Transit System Plan will get a massive political boost and qualify for a chance to seek federal money.

Routes left out could be forgotten for decades.

For the next three weeks, the public will have a chance to pick favorites among 29 segments, worth up to $25 billion, that made it through an initial round of screening. To make public involvement easier, and perhaps a little fun, Metro this week began offering Web users a chance to "build your own transit system" with a site that lets any computer user compile a collection of routes -- like a mini version of the popular SimCity computer game.

Metro Councilor Carlotta Collette says the process offers the region a chance to think about where to accommodate another 1 million residents expected in the coming 20 years. Light rail and other mass transit solutions can encourage density in areas that have planned for it, says Collette, who is guiding the plan for the Metro Council.

"What are the communities we want to be building in the region, and how can light rail or high-speed streetcar or bus rapid transit help us get the density in the communities that we need?" Collette asks.

The Web tool, says Metro planner Tony Mendoza, isn't intended to tally the public's favorite routes. Instead, he hopes it helps people understand the hard choices that come with limited resources. The tool limits users to spending $2.7 billion of a total $25 billion wish list of routes -- and only on routes that made it through Metro's initial screening.

The tool also prepares users to fill out a 17-part questionnaire that gauges how respondents value various factors, such as ridership, cost and environmental benefits. Questionnaire results will be tallied and used to guide decisions, Collette says.