Chris Hansen, the San Francisco hedge-fund manager who has pledged to help finance a proposed $490 million hockey and basketball arena, with the help of an as-yet-unknown group of investors, on land he owns in SoDo, said today that he would pay for a transportation, traffic, and parking study in the area. The study will be conducted by Auburn-based Parametrix, a firm Mayor Mike McGinn said Hansen himself selected.

Earlier this week, of course, the Seattle Mariners and the Port raised concerns about the impact a third stadium would have on traffic, transit access, and freight mobility in the neighborhood. Mariners spokeswoman Rebecca Hale says the team is "very pleased to hear the news about the plans for the study. That is exactly the sort of thing that we're looking to see."

McGinn said the study would look at issues such as how people would access the new arena; how the transportation system could function more efficiently in the area; and how much parking is currently being used and what the parking impacts of a new arena would be. Additionally, the study would look at the plan to manage transportation near the existing stadium and come up with a transportation demand management plan for the new arena.

Hansen said he doesn't want to do anything to hurt access to the Port or the city's two stadiums. "I'm a Mariners fan, I'm a Sounders fan and I'm a Seahawks fan---and hopefully soon a Sonics fan," he said.

Hansen declined at today's press conference to say how much the study will cost him. "It's safe to say I'm paying for it---it's not falling on the public," Hansen said.  City transportation director Peter Hahn deflected questions about cost as well. "Because the study's being funded by Mr. Hansen, I'll leave the question about how much it's going to cost for later," Hahn said. [UPDATE: Consultant Rollin Fatland, who is working with Hansen, says the study will cost in the neighborhood of $50,000 to $60,000.]

Asked when more information about the study, the criteria for choosing Parametrix, and the study's financing would be public, McGinn responded simply, "We're public agencies, so we'll be transparent."

And, asked whether he---the best-known skeptic about the possibility of cost overruns on the tunnel---was similarly worried about cost overruns on the arena (although the deal would include several safeguards to ensure that the investors would pay in the case of overruns, bankruptcy, or default, the city and county would ultimately be on the hook for stadium costs if other safeguards failed), McGinn responded: "We will, of course, be working out the financial situation to protect the city. It is a very high priority."

Rollin Fatland, a Seattle consultant who's working with Hansen, said the study will be merely a precursor to a full environmental impact statement, which will include a transportation analysis and will be public. He said he'd get back to us about what Hansen is paying for the study.

Hansen, McGinn, and King County Executive Dow Constantine all emphasized that the stadium district already has a lot of transit access; in fact, Hansen said, that's one reason he chose the site for the potential arena. "When we undertook a site evaluation, traffic was one of the key benefits of this area," Hansen said. "That doesn't mean there are not issues. … We're going to work hard to address traffic concerns."

Constantine, waving around at the crowded transit terminal, called the area "easily the single largest transportation hub in the Pacific Northwest." However, he added, "freight mobility here is as much of a priority as the movement of people."

If the study finds a need for major transportation improvements, a reporter asked Hansen, will he pay for them?

"I'm not going to say no," Hansen said, "but we look at our deal holistically. There's a certain amount of capital investment. It's kind of fungible in terms of what goes where. " In other words, Hansen is committing to pay a fixed amount to get the new arena and NHL and NBA teams---$290 million---and what that money goes for is irrelevant to the total amount of funding.

After the press conference, I asked Metro general manager Kevin Desmond if he was worried that Metro, which has faced major revenue shortfalls in recent years, would end up on the hook for additional transit serving the stadiums at the expense of service in other parts of the city.

And I asked him if he was concerned about the fact that the arena would be difficult to access by light rail (the stadium is three-quarters of a mile from the nearest rail station, on the other side of the state’s massive new SR-519 ramps, and accessible only through a confusing street grid). He reiterated Constantine's and Hansen's statements about the ample transit access in the area, and added that the biggest challenge would be improving pedestrian access to the arena. You can overcome a lot of problems, he said, with "good pedestrian pathways. If it's adequate and pleasant to use the pedestrian pathways, people will walk."

Hansen wouldn't comment on negotiations with any particular NBA or NHL teams. (Late last month, a deal to keep the Sacramento Kings---widely viewed as a potential Seattle NBA franchise---in Sacramento hit a snag.) "It's not my priority right now to look at who is the most likely," he said. "Our job is to get a deal in place."