Posts Tagged ‘streets’

Parisian Multiway Boulevard (Source: de.wikipedia.org user Luestling)

A tool for building the city, little known in the United States, is the multiway boulevard.  I was not aware of the term until reading “The Boulevard Book” by Allan Jacobs, Elizabeth Macdonald and Yodan Rofe, the authoritative reference on multiway boulevards.  I had seen roads of this type in my international travels, from Guangzhou to Paris, but didn’t realize their significance until reading this book.

Multiway boulevards are multi-functional roadways, consisting of at least a central roadway, optimized for fast automobile traffic, and side roadways, optimized for low-speed local access traffic and parking.  Medians separate the central roadway from the access roadways, and on well-designed boulevards the medians, access roadways and sidewalks create an extended pedestrian realm.  Multiway boulevards typically have at least four rows of formally spaced street trees.  The median trees visually and psychologically separate the traffic realm from the pedestrian realm.  Pedestrians feel comfortable lingering on sidewalks and medians, crossing the access roadways at will.  Vehicles in the access roadways travel slowly by design, due to the narrowness of the lane, frequent bicycles and pedestrians, vehicles entering or exiting parallel parking, and delivery trucks stopped for unloading.  Multiway boulevards are capable of handling heavy volumes of fast traffic, from 4 to 10 lanes, while providing a safe, quiet and relaxing environment for the adjoining buildings and pedestrians along the roadway.

Multiway Boulevard Cross Section (from the "The Boulevard Book")

In contrast, U.S. traffic engineering focuses on only one function for a road: high-speed traffic corridor, from which pedestrians and businesses stay away, and local access streets, with limited traffic volumes and speeds.  Multiway boulevards can accomplish both tasks within one right-of-way.  The best boulevards, however, do require very wide right of ways.  Absolute minimum is 100 feet wide, more typical are 180 to 250 feet wide.

It is well-known that freeways, whether at grade, in a trench or elevated, are detrimental to cities, separating neighborhoods with deafening and ugly “no-go” zones, and overwhelming the local street grid at off-ramps.  Multiway boulevards are an elegant solution to providing rapid mobility in a city without sacrificing quality of life.  Does your city have any of these roads?


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Vienna, Austria. Source: Wikimedia

Streetwalls are a fundamental component of the built city, which is what we advocate for here at Build the City.  What is a streetwall, you ask?  A streetwall is the “wall” made by continuous multi-story buildings flanking the edge of a street, on one or both sides.  It is the wall the defines the street space.  Streetwalls provide a feeling of shelter and security to pedestrians; shade on a sunny day or possibly a shelter from the rain.  Continuous buildings, doors and shop fronts keep the walker entertained when walking through the neighborhood, making the walk feel shorter.  Street furniture such as sidewalk cafe tables, trees, bike racks, newspaper racks, street food vendors and bus shelters creates both destinations and diversions.  Eyes on the street provide safety.

Buenos Aires, Argentina. Source: Wikimedia

Most large cities (outside the United States) consist primarily of neighborhoods with continuous streetwalls.  Wherever you go, you know you are in the city.  Your viewpoint is limited to streets lined with four to seven story buildings in all directions, and to all the public life contained in those streets.  Paris, Bangkok, London, Guangzhou.  The photos along the left show the variety of streetwall forms, streets and architectures, drawn from four continents.

Tokyo, Japan. Source: Wikimedia

North American suburban environments, however, eschew the streetwall.  Minimum setbacks are the norm, to prevent a building from ever touching a sidewalk.  Who knows what could happen, claustrophobia?  But over the past 60 years the suburban has crept into the city.  Cities all across the U.S. have land use codes similar to suburbs: setback limitations, parking minimums, no requirements for curbs or sidewalks.  The result is that many U.S. cities resemble suburbs more than the cities of the rest of the world. 

Lagos, Nigeria. Source: Wikimedia

Building the city, a process which thankfully has begun in many places in the U.S., requires building streetwalls.  “Breadloaf” apartments or condos – 4 floors of residences over street level shops – are a common building form.  A form that has become hated by many due to bland architecture, repetitive chain stores and a lack of street amenities.    But the advantages of urban density and the creation of streetwalls far outweighs the downsides of these developments.  Due to a combination of poor materials and poor installation, most multi-story residential buildings, particularly here in Cascadia, require replacement of the building facade (“envelope”) within 10 to 20 years to correct water damage.  The building, its 5 story streetwall and all its residents will remain as a permanent feature of the city, while the bland architectural elements will be replaced many times.  They can always to upgraded to something more aesthetically pleasing in the future.  Meanwhile, building by building, block by block, the city is built.

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