Extending Sound Transit's light-rail line north of downtown Seattle would be cheaper, involve fewer risks and face fewer potential construction delays if a proposed station at First Hill were to be eliminated, a staff assessment has found.

But removing the station could neglect thousands of riders who work in major hospitals on First Hill or attend Seattle University, some members of the agency's board of directors said yesterday.

"If we can't serve the density with transit, then why are we building in the first place?" Seattle Councilman Richard McIver asked during a board meeting yesterday of the regional transportation agency.

Sound Transit is in the midst of building a light-rail line between downtown Seattle and Tukwila set to open in 2009. Yesterday the board approved an extension from Tukwila west to Seattle-Tacoma International Airport.

Now, its board is using preliminary engineering, design and cost estimates to determine how far north the agency can afford to build under the Sound Move plan voters approved in 1996 to piece together a regional transportation system. Eventually Sound Transit hopes to reach Northgate, but at this point it's most realistic goal is reaching Husky Stadium.

Sound Transit staff members said the agency could save more than $350 million by skipping the First Hill station, between Westlake and Capitol Hill, en route to Husky Stadium and most likely would complete the project six months earlier in 2016.

Their analysis also found First Hill's challenging soil composition, the depth of its tunnel and a lack of elbow room for construction workers and equipment make it unlikely the project would generate many bids from qualified contractors.

Forgoing First Hill, however, could mean fewer riders between the University District and Sea-Tac (114,000 without the station in 2030 versus 119,500 with a stop at First Hill) and would require light-rail users traveling to First Hill to either hop a bus or walk about a mile from the Capitol Hill station.

If no station is built now, none likely ever will be, said Ron Endlich, North Link Program Manager. The light-rail route would shift slightly west and become more curved, eliminating a straightaway needed to build the station.

That disappoints Michael Gray, president of a coalition of businesses and residents known as the First Hill Improvement Association. Light rail would enable thousands of hospital employees and college students to access the neighborhood without being stuck in traffic aboard Metro buses, he said.

Sound Transit staff will present the costs and an analysis of how transit would serve the area without the station in greater detail at its July 28 board meeting.

The board also approved plans and financing to extend light rail from Tukwila west to Sea-Tac, a $244 million project expected to be done in 2009.

The airport announced yesterday that Sound Transit can move forward even if an expansion of Highway 518, which connects Interstate 5 to Sea-Tac, is delayed.

The 518 project is among dozens that would lose funding should an anti-gas tax initiative succeed at the ballot box this fall. Aviation and planning director Michael Cheyne said the airport's expressway expansion would be able to handle the traffic until 518 is completed.

Karen Gaudette: 206-515-5618 or kgaudette@seattletimes.com