Proposal floated to put parts of Interstates 5 and 405 underground
An innovative proposal to divert Interstate 5 into a tunnel under parts of inner Southeast Portland has revived the long-standing desire of some area residents to tear down the freeway ramps over the east bank of the Willamette River.
The City Council is scheduled to consider a resolution Oct. 19 calling for a master freeway improvement plan that includes studying the pros and cons of building such a tunnel from the eastern end of the Marquam Bridge to the Banfield Freeway.
The study also would include burying portions of Interstate 405 in a similar tunnel under parts of Southwest Portland.
The resolution is being drafted by the Freeway Loop Advisory Group, a 24-member committee appointed in 2003 to study the I-5 and I-405 loop that circles downtown Portland.
It is the first formal follow-up to a study released by the group in July 2005 and will be introduced by Commissioner Sam Adams, who is in charge of the Portland Office of Transportation.
The 2005 report found the 6.5-mile freeway loop vital to both the regional and West Coast economy. But the report concluded the loop already is highly congested and will become even more gridlocked as the regional population increases by a predicted 1 million people over the next 20 years.
'Projected employment and housing patterns through the year 2030 show that, even with aggressive trip reduction, demand is expected to exceed the freeway system's ability to serve it,' the report said.
After studying a range of possible improvement projects, the advisory group concluded that diverting I-5 into an east-side tunnel is the only one that would significantly decrease congestion.
The proposal - called the Full Tunnel - also would divert the southern end of I-405 into a similar tunnel beneath parts of Southwest Portland.
The study estimated that the tunnels would cost $3 billion to $5.8 billion in 2003 dollars, figures pegged to the start of the study that could be twice as high today. The proposed resolution does not commit the council to the project, calling instead for more study of all options, including the tunnels.
The recommendation in the resolution is a victory for Riverfront for People, a grass-roots group that has advocated removing the east-bank freeway for two decades.
'The benefits are enormous, including freeing up more than 40 acres along the east bank of the Willamette River for parks or redevelopment,' said consultant Ron Buel, who co-founded the group to push for creation of Gov. Tom McCall Waterfront Park when he worked for former Mayor Neil Goldschmidt in the 1970s. The group took up the cause of removing the east-bank freeway in the late 1980s.
The group previously had proposed removing the ramps without replacing the freeway or building a below-grade replacement freeway through portions of the inner east side, similar to parts of I-405 on the west side.
East-side business and property owners adamantly opposed both of those ideas because of the potential loss of customers and existing buildings, according to Peter Finley Fry, a land use consultant who specializes in east-side issues.
But, Fry said, the tunnel idea currently is not being opposed by the east-side interests because it overcomes these problems.
'They definitely think it's worth a look, even though they aren't endorsing it at this time,' Fry said.
Fry cautioned that some issues still need to be resolved. They include whether the council would put all east-side freeway improvements currently under discussion on hold until the master plan is finished.
According to Fry, the interchange where traffic moves between I-5 and Interstate 84 is so congested now that it needs improvement work. Fry also believes that the east-side ramps to and from the Hawthorne and Morrison bridges could be redesigned to open up 10 or more acres for redevelopment.
'The business and property owners aren't willing to put all improvements off, but the tunnel idea should be pursued,' he said.
At the same time, both Buel and Fry said it could take 25 years or more of intense work before ground could even be broken on the tunnel project.
'We recognize this is not a quick fix that we can immediately jump into. It will take a long time to fully understand how it could work and find the money for it. But if we don't start looking at it now, it would take forever,' Buel said.