Appraisers will tell you that valuing property is an art and not a science. What a piece of real estate is worth depends on who is asking, and when, and on many other factors, including most notably the definition of value that the client gives the appraiser.
The city values the track and right-of-way for the proposed Lake Oswego trolley (an old Southern Pacific line that runs along the west bank of the Willamette north from Lake Oswego to a point near downtown) at $97 million, or about $16 million per mile. Interestingly, the city values its 4,000 miles of paved streets at $5 billion, or about $1.25 million per mile. (The unpaved streets are apparently free.) The city thus views the railroad right-of-way as worth 13 times more than the same amount of public street.
This may explain why the city can't find the money to repave its streets -- they aren't worth the trouble.