Closing Streets to Cars - for Good
http://www.copenhagenize.com/2013/03/closing-streets-to-cars-for-good.html
March 12, 2013
The neverending story of car dependency:
FUD - Fear,
Uncertainty and Doubt. This is the general feeling when drivers know
that the street they usually drive on, may soon be closed to vehicular
traffic. This feeling has, to some degree, been used by those who decide
to build new roads. In other words, we still live according to Henry
Ford's motto, “With mobility comes freedom and progress”. As someone who
works with urban planning this can be viewed as when the ends actually
justify the means – cities scratched by black tar marks, roads planned
and built with eyes closed.
Now, the results of unconsidered planning are here - we feel these impacts on a daily basis.
Currently, that paradigm is slowly shifting to a new one. In a rather
considerable number of cities, city centres, as well as many other
streets, are being closed to cars.
Nevertheless, there remains constant misconception about closing streets
to cars: chaos and congestion are imminent. All those cars will just
end up somewhere else. On other streets, in other neighbourhoods.
Although considering that some cities have already implemented car-free
streets for quite a while now, it's possible to observe the impacts.
The Braess's Paradox is a statistical theorem that determines that when a
road network is already jammed with vehicles, adding new streets can
make traffic flow even worse. Overall, it encompasses the (wrong) idea
that more roads will improve traffic. According to this paradox,
extending a road network may result in even longer commuting times.
“Ok, but that's on paper. Usually it doesn't happen in real life.” You might say.
In New York,
when the City's Transportation Commissioner decided to close 42nd Street
during the Earth Day celebration, a “doomsday” was predicted due to the
expected generated traffic chaos. We're not talking about any street –
it's the same 42nd street that intersects Time Square and runs past
Grand Central Station. This anticipated doomsday couldn't be further
from what really happened:
traffic flow actually improved. A real world example of the Braess's paradox.
 |
| Calming Times Square. |
This paradox also came up
in an article citing a research paper titled “
The Price of Anarchy in Transportation Networks: Efficiency and Optimality Control”.
In this article, one of the interesting conclusions was, "...simply
blocking certain streets can partially improve the traffic conditions."
Dietrich Braess must be proud.
But let's look at a few other examples. In Kajani, Finland, a proposal
to close traffic through the main square was brought to the table when
the daily traffic was 13,000 vehicles per day. After the authorities
closed it to car traffic, the streets nearby had a slight increase right
after the closing and, after that, the overall traffic had decreased
with hints of “evaporation”.
 |
| Post-pedestrianisation in Copenhagen's City Centre. |
Another common concern when closing streets to traffic is commercial
activity. In the same city, a survey of retailers found that 52% felt
that the decision to close the streets down to cars had improved local
commerce or will improve it in the future.
In Wolverhampton, UK, the “evaporation” of traffic also happened - after
closing down the city centre to cars, 14% of the overall traffic was
reduced in the nearby streets. Also in the UK, in Vauxhall Cross, a
simulation predicted an increase of 267% in traffic queueing. The
results, of course, were quite different: traffic queues were shorter
than before and there was an overall reduction of 2-8% of traffic. Ugh,
talk about cities ruled by computers instead of people.
In Strasbourg, right before the decision to close down streets to cars
in the city centre, the daily traffic was 240,000 vehicles/day. Ten
years later, instead of having the same amount of traffic in nearby
streets, the volume fell by 16%. Predictions were that if this
implementation was not considered, there would have been a traffic
increase of 25% in the city centre by the year 2000. You can check more
of
these facts here.
 |
| Nørrebrogade at rush hour. |
There's a great example in Copenhagen as well. In 2008, Nørrebrogade was closed to cars. In 2009, a
study was performed to assess the overall impacts of closing that street to cars - which had immediate interesting results.
The latest results (2012) show that Nørrebrogade had a:
- 20% increase in cyclists,
- decrease of 45% in accidents,
- 60% increase in pedestrians,
when compared to 2008's levels. Although a part of the traffic has been
redirected to nearby streets, just one year after closing down
Nørrebrogade to car traffic, the overall traffic
was reduced by 10.7%, which means 19,000 fewer cars/day.
 |
| San Francisco Streets. |
In San Francisco, the parking space is restricted to a maximum of seven
percent of a building's square footage. Despite the fact that employment
has increased in the area, traffic congestion is in decline – people
are looking for alternatives, like cycling and walking.
Ok, now that we demystified the expected chaos of closing streets to
cars, let's see what happens when the opposite occurs, i.e. creating
more traffic lanes (or more infrastructure) to deal with congestion
problems.
For decades, roadways have been expanded with the idea that it could
solve problems. This is also a common misconception. Rather than in
writing, Todd Litman explains this in a beautiful way:
In a few words, the more lanes you create, the more traffic volume you
will get. It's also interesting to note the difference from the
projected traffic growth and the actual generated traffic.
 |
| Traditional Traffic Planning in Tokyo. |
There are also more than a few issues attached to traditional traffic
planning (which includes creating more lanes). According to a 2013 study
called “
Smart Congestion Relief – Comprehensive Analysis of Traffic Congestion Costs and Congestion Reduction Benefits”,
there's a whole set of ignored impacts when analysing traffic
congestion. For instance, congestion intensity is often assessed instead
of its costs, thus ignoring the savings created by commuters who
shifted mode or reduced car usage. Moreover, several other factors like
downstream congestion, traffic accidents, energy consumption, pollution
emissions among others, are often ignored. Cost values of generated
traffic congestion, traffic accidents, energy consumption, and
pollution emissions to name a few have been underestimated and ignored.
Additional benefits can come from closing streets to cars. For instance,
street life. Every summer, for three straight days, approximately 11 km
of New York's city streets are closed to cars and open for everything
else.
In 2012, 250,000+ people enjoyed car-free streets under that initiative.
Thus it's possible to conclude that immediately after closing the
streets to cars, there is a slight increase of traffic in the nearby
streets. I guess that's expected. But traffic adapts and the overall
number of cars decreases. After a few years, people just choose public
transportation and/or non-motorised vehicles. The number of
non-essential trips also declines – yes, it may even reduce drivers'
laziness.
Overall, two main points can be extracted from this article: 1) building
more roads doesn't mean alleviating traffic flow but instead could even
make congestion worse; 2) closing a street down to cars improves
pedestrian and cycling share and the overall number of cars will be
reduced, thus less congestion throughout the city.
Mathematicians first said that it's alright to close streets. Reality proved they were right.
This seems about right to me. I like spending time in L.A. Like, Austin, there are great people, amenities and institutions, even if the form isn’t real appealing.
I think when people criticize L.A. for not being urban compared to places like San Francisco or Chicago (I am one of them)what they really mean is this: Too many environments in L.A. lack a sense of place. Almost every environment in L.A. would be a nicer place to spend time if it were less focused on maximizing car-throughput and more friendly to human scaled activity. There are a lot of roads in L.A. and too few streets.
It’s historically correct to say that LA is the densest place that primarily based on the automobile. But as ever-increasing congestion demonstrates, that model can’t go forward, particularly as Southern California’s population continues to grow. The model has to start shifting, and it is shifting, very slowly. LA has many of the “bones” left from its transit days which allow it to reconstruct on a basis other than universal driving.
Agreeing with the thrust of the two previous comments: LA’s streets still are suited mostly for autos. While many agree that LA has good urban bones, LA has only just started to learn to dress its streets for urban life. Urbanity is still LA’s primary challenge.
LA has a very large pre-war downtown and was spared most of the last 60 years by becoming a large immigrant hub. Now that is changing and its slowly becoming the center of the city again.
Its weird thing that many people now think the city is the prototypical Postwar sprawl region of the country when a good portion of its urban form was pre World War II built by streetcars, and inter urban rail. The region used to have the largest streetcar system in the world spanning the entire basin.
The more transit LA builds the more centralized the city will become.
I also take some offense at the implication that Newark’s downtown dead zone was not caused by the same forces than made LA sprawl. Both cities were trying to be more car friendly and became less people friendly, inevitably losing a sense of place. Places are for people not cars, something planners, engineers, and politicians need to figure out.