When Mayor Sam Adams and his council colleagues vote April 20 whether to move forward with a streetcar extension to Lake Oswego, they will do so before answering many key questions.

"There's a lot of due diligence that hasn't been done," Adams says. "We're going into decision making before we know a lot of the answers."

As The Oregonian reported recently, the biggest questions cover the price tag—as much as $458 million, according to the highest estimate in a December 2010 draft environmental impact statement. But before getting too worked up about whether the Federal Transit Administration will fund the project, it's worth examining the rationale for the proposed 6.6-mile rail link.

All transportation projects seeking federal funding must submit a "purpose and need" statement. That statement in this case says, "The need for the project results from: Historic and projected increases in traffic congestion in the Lake Oswego to Portland Corridor...."

That makes sense. Highway 43 between Portland and Lake Oswego is often jammed. And ongoing development at South Waterfront will only add to congestion. The problem for streetcar proponents is that spending hundreds of millions of dollars will not materially reduce congestion, according to projections.

Forecasts show the streetcar will attract 3,400 more "boarding rides" than existing bus service in 2035, but traffic will be little changed. A study shows building the streetcar would shave only one minute off the 33-minute travel time by car from Lake Oswego to Portland State University in the year 2035.

The study found that compared with the "no-build" option of the status quo with existing bus service, the streetcar extension would result in only about a 1.6 percent decrease in the number of vehicles on the road during peak rush hour. 

Jill Gelineau, a lawyer for Public Storage, a  Lake Oswego landowner opposing the project, wrote in an April 11 letter to Portland City Council that the streetcar "will do almost nothing to improve transportation in the Highway 43 corridor in the short or long term."

Adams and the Lake Oswego City Council, which also votes next week to select a "locally preferred alternative," have gotten an earful from project critics, such as a well-funded crew from the ritzy Dunthorpe neighborhood between Portland and Lake Oswego, and Lake Oswego residents who oppose large-scale development in the city's Foothills neighborhood.

Adams and his staff are less focused on reducing Highway 43 congestion than in boosting development in Johns Landing. As with the proposed Foothills development, significant zoning changes are required before development along the line happens. Adams acknowledges next week's vote puts the train ahead of the track. 

"The zoning is not yet in place here or in Foothills," he says. "In other cases, like the River District, the zoning was done concurrently."

The difference is, Metro is running the planning process because the deal crosses municipal boundaries, unlike the River District, which lies entirely within Portland. But Adams and his staff are willing to move both forward because they believe the streetcar will catalyze development and they think the actual cost to Portlanders will be relatively small.

Paul Smith, Portland's lead planner on the project, says the city would contribute $14 million of what he says is a $350 million total price tag. About $6 million would come from a local improvement district in Johns Landing; another $5 million would come from system development charges on new projects. That math is likely to be good enough for at least four of the five votes on the council (Commissioner Dan Saltzman favors ending the track at the Sellwood Bridge). 

But if the city's math is wrong or the feds don't cover 60 percent of the cost as city planners hope or reject lofty valuations of right of way as part of the local jurisdictions' contribution?

"This deal will require a lot of significant political lifts," Adams says. "If they don't happen or our partners in Lake Oswego can't find consensus, then maybe the streetcar doesn't make sense."

FACT: The environmental impact statement projects the number of households in Lake Oswego's transit corridor will increase 51 percent between 2010 and 2035, despite increasing only 6 percent from 1990 to 2005. That projected increase doesn't include the Foothills development.