Archive for July, 2010

Self-Healing Roads: Strong Track Record of Success for Highway Removal

Thursday, July 22nd, 2010

The idea that a highway segment can be replaced with an urban boulevard without creating significant traffic problems strikes some people as unlikely.  Time and again around the world, though, highway removals have shown traffic patterns to be flexible and adaptive, with doomsday predictions of gridlock proving false.  This “self-healing” nature of road networks suggests that City to River’s proposal to replace the downtown portion of (soon-to-be-former) Interstate 70 with an urban boulevard is likely to cause minimal adverse effects on the vast majority of drivers traveling through the St. Louis area.

Although it seems counterintuitive, many traffic experts understand that creating more road capacity via highways actually tends to increase congestion in urban areas.  Highways force (or, at least, cause) too many drivers to use a single route that often has inadequate access points to a city, rather than distributing the traffic more evenly over a network of roads.  High-speed routes introduce inefficiencies by inducing drivers to go out of their way in an attempt to save a minute or two, as opposed to taking a more direct route on local streets.  Even the mere ability of drivers to move faster can cause traffic problems.  As explained in a 2006 SmartMobility report, “[s]peed is confused with capacity.  An urban street can carry more vehicle traffic at 30 m.p.h. than it can at 50 m.p.h. because the capacity is controlled at signalized intersections.”

More and more cities are recognizing the problems caused by highways cutting through their urban cores, and the benefits that can be achieved when those highways are removed.  Highway removal and restoration of the urban grid thus has become a preferred choice for an ever-growing number of cities.  Even the U.S. Department of Transportation has recognized that replacing an urban highway with a surface boulevard is the more financially and environmentally sensible choice for some cities, and is consistent with USDOT’s goal of ensuring that “[p]edestrians, bicyclists, motorists and public transport users of all ages and abilities are able to move safely and comfortably along and across a complete street.”

When a highway is eliminated, traffic tends to adapt quickly.  Drivers spread across grid networks, with replacement streets serving much of the same traffic and previously underutilized routes absorbing the rest.  Often, traffic in the impacted area appears to simply “disappear,” as drivers adopt alternative routes, travel times, and even modes of transportation.  As noted in a 1998 study that analyzed the effects of seventy cases of reduced road capacity (although not necessarily highway removal), “traffic problems are usually far less serious that predicted,” and “widespread, long-term disruption is hardly ever reported.”

These are more than abstract theories, but rather have been proven time and again in successful urban highway removals around the world.  Here are just a few examples of highway removals that have not caused the major traffic problems predicted by experts and feared by the public:

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Distinctions Between City to River and the City+Arch+River Design Competition

Thursday, July 15th, 2010

In the past few weeks City to River has substantially grown its support base – both popular and among local stakeholders – for our vision of downtown St. Louis relieved of the barriers that its Interstate lanes create.

City to River’s goals are ambitious, and on several fronts dovetail with those of the Framing a Modern Masterpiece Competition.  While our goals are similar, however, they are not identical.  City to River’s mission is to advocate for the renewal of connections between the communities of the Central Riverfront and the Mississippi River. Thus these two entities share an exciting new vision for the future of downtown but can be distinguished in ways that we seek to clarify here.

Time: City to River fully understands that while planning must begin now, opening a thriving urban boulevard will not occur on ribbon-cutting day in October 2015.

Space: Removing both the depressed lanes and flanking barrier transitions in front of the Arch grounds as well as the elevated lanes that proceed north exceeds the formal boundary of the Competition.

Funding: Because our vision exceeds the chronological and spatial limits of the Competition, portions of it will require other funding sources.

In short, we think of the boulevard as a long-range goal whose full realization may lie beyond the competition horizon, and have worked to encourage the design teams toward its seamless inclusion among their other contributions. City to River’s success will come in stages, with both legislative and physical milestones, any number of which could themselves merit celebration at the conclusion of the competition.

Moreover, while we consider the boulevard essential to the successful re-visioning of the Arch grounds, it need not be exclusive.  The boulevard is not incompatible with additional forms of connectivity. A design that anticipates this comprehensive solution to problems recognized by all in the region will generate more public support and fuel anticipation for the transformation of the Gateway Arch from St. Louis’ icon to its heart.

Like the Framing a Modern Masterpiece Competition, City to River has ambitious goals for a dramatically transformed American city.  We relish the challenges ahead of us and hope to find evidence of shared enthusiasm for our vision St. Louis’ future when the five final concepts are unveiled later this summer.

Freeways in Cities: An Uneasy Connection

Wednesday, July 7th, 2010

In the half-century plus since Congress authorized its legislation, the impact of the Interstate Highway System on American transportation has been nothing short of transformative.  America’s freeway system created a more accessible nation, allowed us to more easily reach our distant family and friends, and revealed the promise of the open road.  But, like so many large-scale government programs, it is not without its share of problems.  One fateful component of the plan has had particularly damaging effects on American cities – the decision to allow freeways to directly enter our urban cityscapes.

Norman Bel Geddes, considered by many the conceptual father of the Interstate Freeway System, first proposed the idea of an interstate highway system to President Franklin Roosevelt just prior to WWII.  Bel Geddes had been impressed with the development of limited access roads in Europe, particularly the German autobahn.  However, he warned explicitly that this new system should not interfere with existing street networks, arguing that it would disrupt the efficient distribution of traffic.  In fact, Bel Geddes concluded:  “the interests of local traffic are exactly opposite to those of through traffic… Of all the vehicles on the road, only those shall enter the community which actually have business there.”  This view was not lost on the Eisenhower administration, as the President agreed that interstates should “contain only roads that carry intercity traffic around and into cities” and advocated that urban highways not be part of the plan.

Unfortunately, state and municipal policy-makers saw what they believed to be a unique opportunity to employ highway engineering as a means to help remediate some of the perceived major issues (urban divestment, social demographic shifts, etc.) that were facing American cities at the time.  Mayors and municipal associations testified strongly in favor of the Interstate System because of the benefits the cities expected to receive from urban highways.  Despite last-minute actions by the Eisenhower Administration to have them removed from the Federal-Aid Highway Act of 1956, urban Interstates played a large role in Congress’ decision to pass this transformative legislation and thus were included. So, with heavy municipal support, the Federal Government steamrolled its way through the heart of many of America’s great cities.

I-70 construction

Construction of I-70, 1964

The new interstate highways, mostly completed from the 1950s to the early 1970s, had enormous consequences. In large metropolitan areas, interstates linked central cities with emerging postwar suburbs, issuing in the age of automobile commuting while undermining what was left of inner-city mass transit.  The effect of the urban interstates was profound.  Predicated on the slum clearance policies of the past, urban expressways were built directly through long-established inner-city residential communities, destroying low-income housing on a vast and unprecedented scale.  While some new development was stimulated in downtown areas as a result, the lion’s share was pushed out to suburban areas and took shape into the shopping malls, office parks, and subdivisions so familiar today.

San Francisco Embarcadero, photo by vision63

As the deleterious effects of the urban interstates began to mount, a movement began to build, calling for certain urban expressways to be removed in favor of the traditional urban street grid that once helped make American cities the most vibrant and prosperous in the world.   Cities such as New York, Milwaukee, San Francisco, and Portland, removed entire urban sections of the interstate with little or no lasting disruption to traffic conditions.  In these cases, the existing roadways were more than adequate to support the additional traffic.  Each of these cities also saw significant and measurable economic and civic progress predicated on highway removal.

It is time for St. Louis to take a closer look at what these cities were able to accomplish and start taking the right steps to ensure that the divisive stretch of Interstate 70 cutting through downtown be removed.  Only then will our city recapture its true essence as a livable, walkable community.  After all, that’s what the founders of the freeway system and President Eisenhower had in mind all along.

Sources:

Bel Geddes, Norman. Magic Motorways. New York: Random House, 1940.

Removing Freeways – Restoring Cities. Siegel, Charles.  2007. The Preservation Institute. 21 June 2010.

Eisenhower Interstate Highway System Web site. 2009. 18 June 2010.