I recently had a client ask me to look at a local park disfigured by freeway construction bifurcating the neighborhood and cutting residents off from this very expensive and valuable amenity. Environmental problems. Social problems. Economic problems. Could anything be done? What are best practices today?
In the aftermath of the 1989 Loma Prieta earthquake, San Francisco tore down (after much gnashing of teeth) two double-decker expressways, the Embarcadero and the Central freeways. But these were just stub-ends of a 1960s Caltrans’ fantasy of elevated expressways crisscrossing the city. Portland Oregon demolished the Harbor Drive Freeway and replaced it with a park in the late ‘70s, but that artery had been rendered unnecessary by a new I-5 bridge routing traffic along the other side of the river.
San Diego has Teralta Park, on a lid over the still-flowing I-15, and there is Memorial Park in La Cañada Flintridge, over the junction of I-210 and SR 2. These are real transportation arteries and not about to be abandoned today. So in those cases, the “park on a lid” made sense, once the money could be found.
As I was researching other “fixes” to the urban destruction caused by insensitive urban freeway construction, the February 2017 Landscape Architecture magazine arrived, featuring a special section on both attempts to make spaces under elevated freeways less oppressive, and better yet, building landscaped lids over depressed freeways. We all know about Boston’s “Big Dig” that took the elevated Central Artery, and replaced it with an underground freeway with a park on top. This cost $14.6 billion in 2007 dollars when it was completed, including the linear park on top.
But I was pleasantly surprised to learn that there are currently 20 other parks over or replacing highways in the US and at least another 26 in some stage of proposal. Various articles in that magazine highlight projects in Houston, Toronto, Washington D.C., and New York City. What further piqued my interest was that today the operative motivations for freeway removal are as much economic as they are social or environmental. Architects and landscape architects and planners and just plain folk have been ruing urban freeways almost since the first one crashed through an historic downtown. But Landscape Architecture quotes Peter Harnik, the co-founder of Rails to Trails and until recently director of the Trust for Public Lands’ Center for City Park Excellence: “For the first time, we have a combination of the technology to cover them and the land value to make it worth doing.”  In this era of fiscal scarcity, we need to look for public private solutions to infrastructure problems.
More and more, far-sighted developers calculate that a lid over a freeway is cheaper than buying an equivalent acreage in high-value downtowns, even if such vacant or underutilized lands were available. Freeway lids and new building construction above also has the potential to begin to restore the legacy of social destruction of neighborhoods and the walling off of poorer largely minority residents. Construction over freeways presents both technical and institutional challenges, but it has been done enough times now that we know it’s possible.
In the District of Columbia, Property Group Partners are building a 7.5 acre, $1.3 billion project with five-130 foot high, mixed use commercial, office and residential buildings, totaling 2.2 million leasable square feet. All of this, plus 1.5 acres of open space, over the 3-block long, 200 foot wide, eight lane Center Leg Freeway (I-395). The lid will be completed this year, and the first building is projected to open in 2018. When complete in 2022, the project is anticipated to generate $40 million per year in property taxes alone.
If $1.3 billion sounds expensive, consider Hudson Yards, two superblocks on the West side of Manhattan. Related Companies is in the midst of constructing a $25 billion 28-acre neighborhood with 18 million square feet of mixed use, all over operating rail yards.  $25 billion!
Is there some lesson here for us? I am having trouble applying this to my client, as land value there won’t yet justify, in effect, constructing building sites over the freeway. But the operative word is “yet.” Mark Twain said something like “buy land, they aren’t making it anymore.” But assuming we continue to progress as a society, downtown urban land will become too valuable to waste on freeways. We will make more land, and heal some of the worst wounds left by 1960s thinking. Who knows what Twain would say.
Parcel 18 on the Rose Kennedy Greenway. Photo by NewtonCourt
Klyde Warren Park, Dallas, Texas. Photo by Joe Mabel, Wikimedia Commons
Construction at Hudson Yards (2014) Metropolitan Transportation Authority of the State of New York, Wikimedia Commons
 “Goodbye Highways”, by Nate Berg, Landscape Architecture magazine, February 2017, pp 74 et seq.
 “City, Heal Thyself”, by Braulio Agnese, Landscape Architecture magazine, February 2017, pp 116 et seq.
 “A Seven-Foot Sandwich, by Alex Ulam, Landscape Architecture magazine, February 2017, pp 82 et seq.