Note: This is a guest post from Daniel Friedman, a member of the Portland Downtown Neighborhood Association board. Friedman is an emeritus psychology professor at Antioch College where he taught for 21 years before retiring and moving to the South Park Blocks in 2001.
Friedman grew up in Columbus, Ohio and sees in its new capped freeway a reminder that Portland should revisit its own I-405 capping plan first forwarded in the 1990s by then-mayor Vera Katz. His proposal here also comes just days after the city of Vancouver, Washington announced the results of a design competition (won by Portland firm Allied Works) to cap I-5 to re-connect the east and west halves of the city.
Columbus, Ohio, like any number of American cities, has sent planners and public officials to Portland to ride the streetcar and to study up on transit-oriented development and other urban-planning innovations. Now it may be time for Portland to send a delegation to Columbus.
What Portlanders would see in Columbus is a potential solution to the drastic rupture created in the downtown streetscape when Interstate-405 was built in the late sixties.
I-405 divides Goose Hollow from Downtown Portland, forcing pedestrians to cross the freeway on bleak, noisy, often-deserted overpasses whose narrow sidewalks leave them precariously close to fast-moving traffic. Crossing the canyon-like I-405 is dull and unpleasant and discourages pedestrian travel between two dynamic and rapidly developing neighborhoods. The I-405 freeway creates a dead zone in the middle of what is otherwise one of the nation's most walkable central city districts.
Columbus faced a similar problem: a desolate freeway overpass that separated the downtown area from Short North, a densely-populated, mixed-use neighborhood, not unlike NW 23rd. Pedestrians were forced to trudge across a forbidding, windswept highway overpass in order to travel from Short North to the city's Convention Center, Public Market, Arena District, and on to downtown.
Inspired by the Ponte Vecchio (pictured above), the Arno River bridge that has housed shops and artisan workspaces since at least 1345, Columbus developer Jack Lucks proposed construction of retail storerooms on both sides of the street, on platforms extending out over the interstate.
Lucks' innovative solution—which came to be known as the 'I-675 Cap'—has won a number of design and planning awards, including a Charter Award from the Congress for New Urbanism.
This aerial view shows the basic design: Three parallel "bridges" across the freeway. The center bridge carries North High Street. Shops and restaurants are located on top of additional bridges which extend out along either side of the original freeway overpass.
The retail platforms are 38-feet wide on one side and 57-feet wide on the other. Completed in 2004, the Cap contains 26,000 square feet of retail.
By constructing platforms for shops and restaurants along the sides of what was once a derelict interstate-highway overpass, this retail-focused freeway cap has reconnected Downtown Columbus with the adjacent Short North arts and entertainment district. As they stroll along the Cap, many pedestrians aren't even aware that they're crossing an eight-lane interstate highway.
The I-670 Cap is one of the few freeway caps in the US that consists of retail and restaurant space rather than parkland. The advantages of the retail approach are two-fold: (1) Revenue from retail users fully or partially pays for development; (2) Continuous retail pulls pedestrians across the freeway, seamlessly linking formerly divided neighborhoods.
Imagine several freeway caps, each containing small retail spaces, spanning I-405, reconnecting downtown Portland with Goose Hollow. Perhaps the strongest candidate for a cap would be SW Morrison Street, since there are already proposals on the table to designate it as downtown's signature East-West shopping street. [See: Portland Downtown Retail Strategy-2009 , Downtown Portland Retail: A New Renaissance ]
With a retail-focused cap to entice pedestrians across I-405, Morrison has the potential to evolve into a continuous retail and entertainment corridor extending all the way from the Willamette to PGE Park (0.9 mi).