Sep. 14--When the trains begin running today on the opening segment of DART's new Green Line, the transit agency will unveil the longest expansion of light rail in North America.

It triggers four years of growth that by 2013 will double daily rail riders and double the length of a DART rail network that has been 26 years in the making. And it finally will begin to deliver on an old promise to make Dallas Area Rapid Transit mean more than just a way for some downtown Dallas commuters to get to work and back.

The new stations that will open just ahead of the State Fair of Texas will attract fewer than 2,000 round-trip riders per day in the first couple of years -- and they certainly won't end Dallas' dependence on the automobile.

But over the next 15 months, the four stations east of downtown will be followed by 16 more along the 28-mile Green Line, stringing communities together from as far north as Carrollton to as far south as Pleasant Grove.

And that's only a beginning: The $1.8 billion Green Line may be the longest light rail project on the continent, but it's just the vanguard for what will be four solid years of expansion.

By 2013, DART will have spent $3.3 billion in construction, adding service to Irving, Las Colinas and D/FW International Airport on the Orange Line. Downtown Rowlett and Lake Highlands will welcome new stations as well on the expanded Blue Line.

The flurry of activity has employed thousands of workers. Within four years it will result in a transit system that runs 48 trains through downtown Dallas every hour -- already prompting more frequent red lights. That's 62 rail stations and about 90 miles of track.

"This is the largest light-rail construction project in America," DART president Gary Thomas said. "Nobody is doing what we are doing right now. That's exciting. It really is."

Paying the price

It also is expensive.

Residents of Dallas and 12 nearby cities -- many of which are still waiting for rail service -- have paid about $5 billion in local sales taxes toward DART since 1983, when voters agreed to raise local rates by a penny.

The opening of the Green Line has thrilled DART supporters and given new hope to neighborhoods where the trains are seen as the best bet for an economic lift.

Downtown Dallas resident Branden Helms said the rail line has changed his life. Three years ago, he moved downtown and quickly found that he and his wife no longer needed two cars.

"More and more, I was using the car less and less," said Helms, 29. "One day I went down to the car and there was a layer of dust on there."

But stories like Helms' remain lonely exceptions.

After 26 years of collecting taxes, and more than 12 years of running trains, DART's rail lines have had only limited impact on the daily commutes of most of the 2.4 million people who live within the agency's 13-city service area.