Why are cities removing their freeways? A systematic review of the literature

Abstract

A scientific consensus has recently emerged suggesting that the dominant twentieth century paradigm of solving transportation congestion problems by building more freeways failed. The legacy of the freeway construction era is clearly visible in polluted and congested cities worldwide. To battle these ills, planning academics have been promoting more sustainable built form aligned with dedicated public/active transport provision. Partly as a result of the push coming from academia, a number of cities have sought to remove their freeways and replace the freed up space with alternate transport infrastructure, such as streets and boulevards. To discern if the transportation planning profession is currently undergoing a paradigm shift or whether freeway removal is merely a temporary fad, we have conducted a systematic review of the literature. In this article, we unpack the underlying reasons which have led some cities to removing their freeways. Results reveal that a paradigm shift has arguably not yet taken place in transportation planning. While many cities are creating human-scale and active transport spaces, currently these spaces tend to coexist alongside freeways. American cities, which were once the pioneers of freeway construction, appear to be lagging behind cities in Europe and Asia in this respect. If the current pace of freeway removal continues, it may take a few decades before the transportation planners, politicians, policy makers, and communities adopt radically different norms, methods, and goals. However, a radical approach may need to be taken sooner given alarming global warming predictions.

Full text

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Why are cities removing their freeways?
A systematic review of the literature
Authors
Ms Fahimeh Khalaj, f.khalaj@uq.edu.au
Dr Dorina Pojani, d.pojani@uq.edu.au
Prof Neil Sipe, n.sipe@uq.edu.au
Prof Jonathan Corcoran, jj.corcoran@uq.edu.au
All authors are at the University of Queensland, Australia
This is an Authors’ Original Manuscript of an article whose final and definitive
form, the Version of Record, has been published in Transport Reviews, 2020,
copyright Taylor & Francis, available online at:
https://doi.org/10.1080/01441647.2020.1743919
Abstract
A scientific consensus has recently emerged suggesting that the dominant 20th century
paradigm of solving transportation congestion problems by building more freeways failed. The
legacy of the freeway construction era is clearly visible in polluted and congested cities
worldwide. To battle these ills, planning academics have been promoting more sustainable built
form aligned with dedicated public/active transport provision. Partly as a result of the push
coming from academia, a number of cities have sought to remove their freeways and replace
the freed up space with alternate transport infrastructure, such as streets and boulevards. To
discern if the transportation planning profession is currently undergoing a paradigm shift or
whether freeway removal is merely a temporary fad, we have conducted a systematic review
of the literature. In this article, we unpack the underlying reasons which have led some cities
to removing their freeways. Results reveal that a paradigm shift has arguably not yet taken
place in transportation planning. While many cities are creating human-scale and active
transport spaces, currently these spaces tend to coexist alongside freeways. American cities,
which were once the pioneers of freeway construction, appear to be lagging behind cities in
Europe and Asia in this respect. If the current pace of freeway removal continues, it may take
several more decades before the transportation planning profession adopts radically different
norms, methods, and goals. However, a radical approach may need to be taken sooner given
alarming global warming predictions.
Note: All accompanying tables and figures are the end of this document.
Keywords
highway removal; freeway removal; paradigm shift; transportation planning; boulevards

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Introduction
The United States is considered to be the land of freeways, epitomized by cities such as Los
Angeles and its spaghetti-like junctions. In reality, the concept of freeways was initially
developed by Europeans. The very first proposal was by a French engineer, Eugène Hénard, in
1906 - for a never-built clover-leaf intersection. A few decades after, Italy built its first
autostrada to connect Milan and Varese while Germany built its first autobahn to connect
Bonn and Cologne (Udy 2004; Schipper, 2008; Vahrenkamp, 2010). However, these were
inter-urban roads. While European cities too faced traffic congestion to varying degrees during
the pre-war period (Jones & Hervik, 1992; Bonnel, 1995; Pucher & Lefevre, 1996; Vuchic,
1997; Downs, 2004), they continued to prioritize public and pedestrian transportation at least
until WWII. The first urban freeway in Europe was not built until 1958 in the former West
Berlin.1
In the large North American cities of the pre-war era, car-based congestion emerged as a
problem as early as the 1920s and ‘30s (Davis, 1997; Kraft-Klehm, 2015; Poole, 2018). Not
only did congestion threaten individual citizens, but also downtown business owners (Brown,
2005; Brown, 2006). To cope with rising congestion and traffic accidents, a number of
strategies were adopted including: social reconstruction (altering citizens perception of streets’
customary use); physical reconstruction (reclassification of street layouts, widening of streets,
and opening of new streets); and, traffic regulations and signage. Most of these solutions
enjoyed only temporary success, in the longer term becoming largely ineffective due to
growing car use (Brown, 2005; Brown, 2006; Norton, 2008).
New York – a city which today is regarded as a transportation outlier in the United States, due
to its extensive rail system – was in fact an early supporter of “express thoroughfares for
automobiles.” In 1923, Dr. John H. Harriss, New York’s Special Deputy Police Commissioner
in charge of traffic, proposed the following:
“The next step inevitably is to create a system of express thoroughfares for automobiles. If we don’t,
we’re sunk. But these floods of motor cars which constantly threaten to swamp us can be handled easily
enough if we clear a few wide traffic channels through which the cars can flow along faster than at
present. We must provide express streets for them in the heart of our big cities: with express boulevards
connecting into the suburbs and the country. We must do this quickly and on an extensive scale (New
York Times, 11 March 1923, p. 4)”
Therefore, early transportation planners developed new urban roadways, which featured
‘limited access’ and ‘grade separation’ and eliminated ’obstacles ‘such as traffic signals and
curves. These new road designs allowed for greater volumes vehicles to travel at higher speeds
(Brown, Morris, & Taylor, 2009; Brown, 2006; Brown, 2005). It was from these seeds that the
urban freeway was born.2
Not only were freeways thought to be capable of alleviating traffic congestion inside cities; for
a time, they were also regarded as an effective and permanent answer to all manner of
transportation woes (Brown et al., 2009; Brown, 2006; Brown, 2005). Freeways were purported
to help decrease the number of traffic injuries, increase people’s access to jobs and services,
facilitate the movement of goods, reduce vehicles operation costs, fuel consumption and tyre
wear (Billings, Garrick, & Lownes, 2013; Napolitan & Zegras, 2008; Davis, 1997; Cox &
Love, 1998; USFHA, 1970). Having a freeway cutting through one’s city space was considered
as a sign of modernisation and a vital component local economic development. Building
freeways was viewed as ‘inevitable’ - lest a city be left behind in the urban completion race
(Napolitan & Zegras, 2008). Consequently freeway construction took off in the 1950s and
1960s, as substantial federal funding was allocated specifically for this purpose (Rose & Mohl,
2012; Brown, 2006).

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In developing freeways, American cities had to contend with two competing visions: those of
city planners, and those of transport engineers. Planners were more concerned about integrating
freeways into the overall built environment; they emphasized the importance of considering
the social and land-use impacts of engineering works. By contrast, engineers prioritized traffic
flow, high speeds, and efficiency of vehicle movements inside cities. To them, freeways were
an amenity for motorists rather for the city as a whole.
Through the 1930s, freeway development plans tended to reflect planning visons. This balance
flipped in the post-war period: by the 1950s engineering visions had gained the upper hand. To
understand why, one has to follow the money. At the time, urban freeway construction was
funded directly by the federal government. Therefore, cities (and their local planners) did not
have much control over the freeway development plans within their territory. A bias toward
the “scientific method” - broadly understood as quantitative measurement - also explains the
supremacy of engineers over planners. Traffic service data could be directly measured to
support engineers’ visions whereas planners’ data was more qualitative and therefore perceived
as less reliable (Brown, 2006; Brown, 2005).
However, by the 1970s, the honeymoon was effectively over. As many of the purported
benefits of freeways failed to fully materialize, transportation researchers began to disown
freeways (Möser & Bamberg, 2008). At a time of economic stagnation, it was relatively easy
to show that the job growth produced from freeway construction was not commensurate with
the environmental damage caused (Brown et al., 2009). A theory was established that freeway
construction (or expansion), instead of alleviating traffic, in fact led to greater travel demand
as a result of ‘induced travel’ - also referred to as ‘latent demand’ (Kenworthy, 2007; Jha &
Kim, 2006; Downs, 2004). Air and noise pollution were empirically shown to be higher in
close vicinity of freeways, thus posing a threat to human health and wellbeing (Pojani & Stead,
2015; Kenworthy, 2007; Jha & Kim, 2006; Downs, 2004).
The presence of freeways visibly transformed land-use patterns by encouraging low-density
sprawl and decentralization. This is a well-documented consequence of freeway construction
(Farmer & Perl, 2018; Litman, 2013 and 1999; Brown et al., 2009; Baum-Snow, 2007). Beyond
physical planning issues, the economies of inner cities showed signs of decline as freeways
proliferated. With the middle classes fleeing to the suburbs, inner cities were depleted of
population; therefore retail stores lost their customer threshold (Kraft-Klehm, 2015). Even
physical inactivity, obesity, and a range of chronic diseases came to be associated with the
presence of freeways, which enabled sedentary, car-oriented lifestyles (Brownstone & Golob,
2009; Lopez-Zetina, Lee, & Friis, 2006; Dodson & Sipe, 2006; Soltani & Allan, 2004; Handy,
Boarnet, Ewing, & Killingsworth, 2002). Once global warming emerged as a problem, an anti-
freeway stance was solidified in academic planning circles.
As for laypeople: some communities (particularly poor, minority ones) grew disillusioned with
freeways as they did not derive much benefit and, at the same time, experienced firsthand large-
scale relocation, exposure to air pollution, and poor aesthetics (for example, associated with
elevated freeways). Sometimes freeways were designed with the (unstated) intention of
separating white communities from neighboring black communities or to clear slums for future
CBD development (Lydon & Garcia, 2015; Brown, 2006; Brown, 2005; Mohl, 2004). Some
communities - for example, in the San Francisco inner city - saw freeways as a threat to their
historical built tissue, and mounted major revolts against their construction (Figure 1). Here,
freeways came to be viewed as eyesores, unbefitting of attractive, vibrant and prosperous urban
areas.
Grassroots anti-freeway movements produced different outcomes in different cities, based on
local characteristics such as physical layout, demographic composition, historical patterns, and
politico-administrative structures (Cervero, Kang, & Shively, 2009; Downs, 2004; Cairns,
Hass-Klau, & Goodwin, 1998). But overall, they succeeded in halting the construction of many

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planned urban freeways (Mohl, 2004). While car travel and traffic congestion kept growing,
by the 1980s the era of major urban freeway construction was nearly over. Many academics
(though not all) became highly critical of the dominant 20th century paradigm of solving
transportation problems by building more freeways. The ideological debate continues to this
day.
Partly as a result of the push from academia, but also due to pressure from urban communities,
the 1990s saw municipalities seek out more sustainable solutions to urban mobility and
development issues (Lydon & Garcia, 2015; Weiner, 2008). A number of cities started
removing their freeways and replacing them with streets and boulevards (Figure 2). In
conjunction, significant amounts of money and effort were invested in revitalizing inner cities
(Lang & Danielsen, 2017). This process accelerated at the turn of the millennium (see
Appendices 1 and 2). Cities elsewhere in North America (e.g., Vancouver) adopted road dieting
as a guiding principle (Cervero et al., 2009).
While the degree of success varies from city to city, new approaches to solving transportation
problems - once again guided by planners rather than engineers - appear to have been beneficial
in terms of creating pedestrian and bicycle paths, redesigning entertainment districts, attracting
cultural events, and beautifying waterfronts. In turn, these urban design interventions have
assisted economic development by boosting land values and retail turnover. The environment
has benefited too as air and noise pollution has decreased and physical activity has increased
(Rose & Mohl, 2012; Napolitan & Zegras, 2008; Cervero et al., 2009; Cairns, Atkins, &
Goodwin, 2002). Meanwhile, concerns about rising traffic congestion following a freeway
removal have failed to materialize: evidence suggests that people have adjusted their travel
behavior resulting in ‘reduced demand’ - the opposite of ‘induced demand’.
However, does this process of freeway removal constitute a ‘paradigm shift’ in transportation
planning? The concept of ‘paradigm shift’ was coined in 1996 by Thomas Kuhn. He theorized
that, for a paradigm shift to occur there needs to be admission of failure of a previously
dominant paradigm, as well as a crisis situation - as described above in the case of freeway
construction. In addition, a professional community needs to go through a ‘perceptual’ or
‘gestalt’ transition, at the completion of which the profession is redirected and has adopted
different norms, methods, and goals (Kuhn, 1996).
As ‘academic activists’ rather than ‘neutral’ bystanders, the authors believe that a paradigm
shift with regard to urban freeways is not only desirable but absolutely necessary in the present
time of climate breakdown. Our ideological position is that freeways have no place inside cities
and cities must be for people rather than cars.3 To discern whether (and/or the extent to which)
the transportation planning profession is currently undergoing such a paradigm shift (rather
than simply responding to the push from academia and ad hoc resident protests), we have
conducted a systematic review to identify the underlying reasons that have led some cities to
remove their freeways. Furthermore, we are also interested in identifying what replaces the
removed freeways. These questions are explored below, after a brief overview of the systematic
review protocol.
Systematic review: Protocol and analysis
A systematic review is an effort to gather all research that is relevant to a scientific inquiry.
The process is conducted based on clearly defined and transparent criteria for inclusion or
exclusion of studies so as to minimize the researchers’ own biases. The final summary is meant
to be both comprehensive and objective (Klecha & Gianni, 2017; Gough, Oliver, & Thomas,
2012; Liberati et al., 2009; Brereton, Kitchenham, Budgen, Turner, & Khalil, 2007). Papers
that form the basis of the present systematic review were identified by searching the following

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five databases: (1) Scopus; (2) Web of Science; (3) ProQuest (social science); (4)
ScienceDirect; and, (5) Google Scholar. The search was conducted in April 2018.
The Boolean-based search terms included phrases related to freeway removal. In the first stage,
only the terms ‘freeway’ and ‘highway’ were searched, combined with ‘removal’ and
‘demolition’. These combinations proved to be inadequate to fully capture the different
terminologies used in different countries to refer to this type of project. Therefore, synonyms
such as ‘expressway’, ‘ring road’ and ‘motorway’ were also added and combined with
‘destruction’, ‘teardown’ and ‘deletion’ in order to identify additional literature.4
In addition to determining the key terms listed above, we developed inclusion/exclusion
criteria, based on the PRISMA Statement for Reporting Systematic Reviews (Liberati et al.,
2009). These are listed below:
• Book reviews were excluded.
• Magazines were excluded.
• Freeways which were planned but never implemented were excluded.
• Freeways whose removal has been decided but not implemented yet were excluded.
• Only studies published in English were included.
• Only studies focusing exclusively on urban infrastructure with controlled access, dual lane,
and high-speed/capacity were included.
• Only studies that outlined the reason(s) for freeway removal were included.
• Only studies that noted the location of a removed freeway were included.
• Only studies that discussed freeways of a significant length (in this case defined as half a
kilometer or more) were included.5
• Only studies that noted the freeway removal date were included.
• Only studies that noted the project that substituted a removed freeway were included.
• Non-urban freeways (e.g., intercity freeways or freeways linking city edges to airports)
were excluded because they are indispensable in places that lack rail transport (Welch,
Mishra, & Wang, 2015; Egan, Petticrew, Ogilvie, & Hamilton, 2003).
These criteria were specifically designed to capture studies which provided some in-depth
analysis of freeway removal projects rather than simply a cursory mention. Beyond the criteria
listed above, there were no restrictions based on publication date, or publication status (i.e., a
published article vs. an unpublished thesis). Table 1 summarizes the results of the search.
The initial search returned 346 papers (Table 1). To select relevant studies for this review, all
identified papers were listed on a spreadsheet for further screening. The first stage involved
identifying and removing 37 duplicate papers. Next, the titles and keywords of the remaining
papers were reviewed to check whether they were relevant to the research questions of this
study. As a result, 101 papers were removed. When the title or keywords were unclear, studies
remained in.
A similar process was repeated for abstracts, resulting in 96 articles being removed. For the
112 remaining papers, a full text review was carried out resulting in the exclusion of a further
67 papers. Thus 45 papers were selected for the next part of the analysis (Table 2). Figure 3
illustrates the process of selection and removal.
The 45 papers included in the final analysis were published between 1995 and 2018. Table 3
shows that the rate of publication has accelerated since 2009 – in line with the pace of freeway
removal cases, which has accelerated since 2000, as previously noted. With regard to types of
papers, most were theses (Master thesis n=11 and PhD thesis n=3) and book chapters (n=14),
followed by journal articles (n=10). The database also included 4 working papers produced by
universities, 1 paper published in a conference proceedings volume, 1 paper presented in an
international symposium, and 1 paper delivered at a seminar (Table 4).

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Articles from the United States dominated the literature. Outside the United States, articles
were distributed as follows:
• Seoul 22
• Paris 7
• Toronto 7
• Madrid 3
• Birmingham 1
While the non-U.S. suite of studies is relatively small, we have included them in order to take
stock of all publications on this topic.
Information extracted from the full set (45 papers) included:
• Location (city and country)
• Freeway name
• Design features
• Year built
• Year removed
• Original freeway length
• Removed length
• Reason(s) for removal
• Substitute project(s)
This information was used to compile Appendices 1 and 2. To isolate the ‘reason(s) for
removal’ and the ‘substitute projects’ - the a priori themes of this study - the data analysis
started with keyword searches. Occurrences of ‘removal*’ and ‘replace*’ within the full text
of the papers were highlighted and comments were entered next to each case. Further, the full
text of the papers was coded to deduct other data related to the a priori themes. The final lists
of the ‘reason(s) for removal’ and the ‘substitute projects’ were visualized using clustered
column charts.
Discussion: Removing and replacing freeways
Both the motivations for removing freeways and the projects that substituted the removed
freeways were different in cities in the United States compared to non-U.S. cities. This finding
is unpacked below, with the key contrasts highlighted. The following discussion is based on
the content of the 45 papers identified through this systematic literature review, which are cited
throughout the text as needed.
Reasons for removal
In the United States, financial concerns were the major reason for removing freeways, followed
by power structure support, structural damage, demand from local communities, as well as
major support from the academic community (Figure 4). Financial considerations are becoming
more salient in the U.S. as the Highway Trust Fund - the main source of maintenance funds for
freeways - has been diminishing. This is due to lower revenues from fuel taxes (hence ‘financial
concerns’), as cars are becoming more fuel-efficient or are using alternative fuels (Kirk &
Mallett, 2018; Leung, Burke, Cui, & Perl, 2018). While market-driven technological
improvements in fuel and vehicles have provided a push, American transportation policy has
been deliberately moving away from using fuel tax revenues as a source of infrastructure

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funding as it has come to recognize the detrimental impacts of the mobility-maximizing
paradigm (Givoni & Perl, 2017).
Meanwhile, the freeways built during 1950s are reaching to the end of their useful lifecycle
and are starting to require massive funding to be redesigned, repaired, or rebuild (Givoni &
Perl, 2017; Rose & Mohl, 2012). (So did several freeways along the Pacific coast, which were
severely damaged by earthquakes.) This situation has given rise to a debate regarding the
limited lifecycle of these structures, which, however, had required a massive public investment
at the outset. (As the very idea of a predetermined lifecycle for major infrastructure projects is
relatively recent, as in the past, public works such as bridges, palaces, or mausoleums were
built to last forever.) A preoccupation with finances does not denote a change in attitude - nor
a paradigm shift.
Another key motivation, which we term ‘power structure support’ is not necessarily associated
with an attitude change among stakeholders either. In a number of cases, politicians, business
leaders, highway engineers, and local suburbanites have agreed to remove an aging freeway
but only under the condition that it be replaced somewhere else in order to serve the growing
traffic (Rose & Mohl, 2012). However, provision of high-quality public transport in exchange
for removing a freeway may make these projects palatable (Givoni & Perl 2017).
Freeways were also removed in response to popular anti-freeway sentiments, and a desire to
redevelop urban areas previously blighted by freeway infrastructure. However, unexpectedly,
these reasons did not top the list here. Although dissenting voices had existed in niche
American communities since the dawn of the freeway construction era, it appears that removal
became a viable option only when freeways became aged or damaged to the point of no return
(Rose & Mohl, 2012; Napolitan & Zegras, 2008). While in the 1970s anti-freeway sentiment
was expressed in the form of protest (by environmental groups or minorities threatened by
relocation), it seems that today more people may simply ‘vote with their feet’ by choosing to
live in more walkable inner cities, free of overwhelming and aesthetically unpleasing freeways.
Although specific anti-freeway protests have abated, Extinction Rebellion demonstrations and
climate marches are growing; those target, in part, excessive car use, fossil fuel consumption,
and road infrastructure. There is also evidence that Millennials are more interested in non-
motorized travel (i.e., walking, cycling, scooter riding) and high quality urban design than
preceding generations (Lang & Danielsen, Myers, 2016; 2017; Circella, Tiedeman, Handy,
Alemi, & Mokhtarian, 2016; Lydon & Garcia, 2015;). These phenomena collectively suggest
that we may be on the cusp of a paradigm shift.
It must be noted that, while some factors appear more dominant in the literature, in reality all
factors are interrelated to some extent. Also, because the process of removing a freeway was
often prolonged, the balance of factors has likely shifted over time, depending on the political
ideology and power structure of the era. Moreover, in a number of cases, the push to remove a
freeway came from a charismatic local politician, who valued urban aesthetics over mobility
(Givoni & Perl, 2017; Kang, 2016; Newman & Kenworthy, 2015; Garrick & Billings, 2013;
Giordano, 2012; Tumber, 2011; Stephenson, 2010; Cervero, 2000). To make the idea palatable
to others and garner political support, he or she later dressed it in financial, engineering,
business or environmental concerns. Sometimes, politicians were “assisted” by the occurrence
of natural disasters, such as earthquakes, in promoting this agenda.
Outside the United States, the motivations for removing freeways have been more explicitly
associated with urban beautification and placemaking (Figure 4). Among the factors were a
desire to revitalize urban areas and waterfronts, followed by a need to reduce physical
obstacles. Global cities ranging from Seoul to Paris and Madrid (but also Birmingham, to a
degree) expected to derive major public benefits and move a step closer to meeting
sustainability goals by clearing their skylines of overpowering freeways and engaging in
human-scale urban revitalization. Power structure support, as well as engineering and financial

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concerns, came up in the international literature too, but not as frequently as in the U.S/-based
studies.
The differences between the United States and other countries highlight the primacy that the
car retains in the American transportation hierarchy. This precludes an open admission that
people and places matter more than car spaces. Canadian cities are more similar to the United
States., in the sense that financial concerns appear to be more decisive here than in Asia or
Europe (Vanstone, 2016). However, the situation may change in the future depending on
local/state/federal politics. International policy transfer and diffusion might also come to play
a larger role in pushing forward decisions to remove freeways. Policy learning has already been
identified as a key factor in the decision to mark for demolition a viaduct in Vancouver (the
Georgia-Dunsmuir) (Farmer & Perl, 2018).
Our findings are not conclusive as there is only a limited number of available studies which
discuss cases of freeway removal. Case studies set outside the United States are particularly
scarce. Hence, we do not elaborate further on this issue, and turn our attention to the types of
projects that have come to replace removed freeways.
Substitute projects
As with the motivations for freeway removal, substitute projects in cities in the United States
differ from those in cities outside the U.S. Most often, freeways in the United States were
replaced by surface boulevards, and to a much lesser extent, recreational spaces or other public
amenities (Figure 5). In most cases another form of car-based infrastructure replaced the
defunct freeway – although at times replete with sidewalks and bicycle paths. In some cases, a
removed freeway simply reappeared elsewhere, in an alternative corridor, or even
underground, as in Boston’s center (Weber, 2018; Rose & Mohl, 2012).
This is another testament to the continuing importance of the car in United States’ urban
planning policy, legislation, and practice. So far, taking city space away from cars and
exclusively reallocating it for pedestrian and cyclist use does not appear to be a preferred option
in cities in the United States. Under these circumstances, one cannot speak of a paradigm shift
in the profession. The evidence merely points to a slight to moderate change in attitude among
policy makers and political leaders. Since research has demonstrated that demolishing a
freeway is considerably cheaper than rebuilding or renewing it, one of the biggest barriers in
removing freeways might be political will rather than a lack of evidence (Givoni & Perl, 2017).
By contrast, in cities outside the United States, removed freeways have been most often
replaced by parks, sidewalks, cycle ways, and public transport lanes (Figure 5). In Seoul and
Paris, linear urban spaces, freed from freeways, underwent major facelifts. This (admittedly
limited) evidence suggests a different approach to urban space transformations in cities outside
the United States: one which prioritizes alternative modes over cars.
However, surface boulevards were also mentioned in the international literature - for example,
in Toronto, Canada and Birmingham, United Kingdom, although these boulevards were
equipped with sidewalks and other pedestrian spaces (Billings, 2011). It is no coincidence that
this occurred in Anglo countries which most resemble the United States in terms of socio-
economic and cultural outlook. In Toronto, the recent decision of rebuilding rather than
removing an aged, elevated freeway – the Gardiner Expressway – suggests still strong pro-car
attitudes in North America.
In Madrid (as in Boston), a freeway was relocated underground to create public recreation
space (Perini & Sabbion, 2016; DiMento & Ellis, 2012; Billings, 2011). While this approach
may have alleviated the air, noise, and visual pollution above ground, it may have also simply
displaced traffic congestion to a place out of sight without making it disappear. Again, it is
difficult to generalize given the small number of cities that have removed freeways.

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While removal may not be an option for many cities yet, some commentators believe that
repurposing strategies, known as ‘adaptive planning’, could be a “low hanging fruit” within
many cities’ reach. Adaptive planning is desirable in any case given the fast pace of
technological development (e.g., driverless cars), demographic change (e.g., ageing), and
attitudinal shifts (e.g., a preference for urban rather than suburban living). Repurposing is
usually considered when using an existing piece of infrastructure and its adjacent spaces are no
longer necessary to fulfil their intended purpose (i.e., transport). An example is New York’s
High Line where a former elevated railway has been converted to an elevated liner park and
trail for pedestrian and cyclists. Another example is the abandoned Tempelhof Airport in Berlin
which has been converted to a public park and now hosts a variety of events (Farmer & Perl,
2018; Givoni & Perl, 2017).
Conclusion
The evidence to date does not point to a paradigm shift in transportation planning, at least not
yet. While there may be agreement that freeways produce externalities and are, in many ways,
detrimental to cities, policy makers do not appear to have fully embraced the notion that this
type of infrastructure is a remnant of another century and, as such, needs to disappear. The
papers included in this review reveal that only about 50 kilometers of freeways have been
removed in the United States, and about 30 kilometers elsewhere.6 While many cities are
implementing policies to create human scale and active transport spaces, for now these spaces
coexist alongside freeways. It may be the case that a ‘perceptual’ or ‘gestalt’ transition is at an
incipient stage. While myriad factors determine whether and how fast freeways are removed,
if the current pace continues, it may take a few decades before the transportation planners,
politicians, policy makers, and communities adopt radically different norms, methods, and
goals (Kuhn, 1996).
American cities, which were once the pioneers of freeway construction, appear to be now
behind cities in Europe and Asia in terms of freeway removal. Auto-mobility still reigns
supreme in the United States. Even where freeways are removed (often to avoid excessively
costly repairs and upgrades), they are often replaced with other car-based infrastructure, albeit
garnished with some active transport space. Globally, ‘power structure support’ has been
essential in the decision to remove a freeway. Urban sustainability may be in the hands of
political decision-makers more than any other groups.
However, the number of cities which have decided to remove freeways, and have been
subsequently reviewed within the academic literature (particularly English language studies),
remains relatively small, and as such it does not allow for conclusive findings. For a more
comprehensive understanding of the causes and consequences of freeway removal, additional
case studies are needed – both set in the United States as well as other situational context.7 To
date there exists only a handful of well-documented freeway removal cases in “superstar cities”
(e.g., San Francisco or Seoul) that have received a disproportionate amount of attention in the
academic literature, while more “ordinary” cities have been largely ignored. Some sources
occasionally point to freeways which are in the process of being removed (or are being
considered for removal). Future studies should follow up on the outcomes of these processes.
Another recommendation that emerges from our work here is that future research needs to be
more systematic in design. All the papers included in the present study employed a wide variety
of methodological approaches; therefore, extracting the data required for comparisons across
case studies was a significant challenge.8 Future studies should report, at a minimum, the
following information: freeway location (city/state/country); freeway name; design features;
year built; removal date; original length; removal length; removal reason(s); and substitute

10
project(s). To survey removal reasons and substitute projects, a mix of quantitative and
qualitative methods would be more effective - especially in more recent cases.
To end on a positive note: more urban freeways will likely be removed as time goes by and
they reach the end of their useful lifecycle. Moreover, a few initial removals may have set in
motion a virtuous circle, in the sense that they have provided planners and politicians with best
practice examples to follow in their own localities, or to use for legitimizing already made
decisions. Furthermore, as lifestyle preferences among Millennials and the iGen shift toward
cities (as opposed to the suburbs), political and business leaders may respond by accelerating
the pace of freeway removal processes. This may result in new freeways only built when
deemed an absolute necessity and located in the urban peripheries where their impact in terms
of pollution and effect on residents’ quality of life are less pronounced.
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16
Figures
Figure 1: Anti-freeway protest in San Francisco (1966). Photo by Chris Carlsson.

17
Figure 2: Freeway removal in Madrid, before (2005) and after (2011). Photos courtesy of the
City of Madrid.

18
Figure 3: PRISMA flow diagram.

19
Figure 4: Reasons for freeway removal in the United States versus other countries. The
numbers on the vertical axis indicate the number of projects.
0
1
2
3
4
5
6
7
8
9
Financial concerns
Urban redevelopment
Academic association support
Power structure support
Structural damage
Local communities demand
Safety concerns
Political ideology
Economic development
Anti-freeway sentiment
Earthquake
Business enterprises support
Reduce physical obstacle
Structure aging
Future safety concerns
Mobility value decreased
Public benefit
Reduce traffic congestion
Air pollution
Underutilised
Relocation
Local coalition of professional Association
Alternative route construction
Security concerns
Temporary shutdown
Existence of precedents
Design flaws
Additional urban space needed
Waterfront rehabilitation
Touristic activities
Environmental concerns
Noise pollution
Reduce decentralization and suburbanization
Transferal of responsibility between regularity bodies
United States Non- US countries

20
Figure 5: Substitute projects in the United States versus other countries.
0
1
2
3
4
5
6
7
8
9
10
Surface boulevard
Sidewalks
Public recreational spaces
Bike lanes
Landscape median
Underground tunnel
New residential developments
Reduced lanes
Security buffer zone
Public amenities
At-grade intersections
Public transport facilities
Parking lots
Bus Lanes
Taxi lanes
Tramways
United States Non-US countries

21
Tables
Table 1. Results of searches in online databases (without removing duplicates).
Database*
Number of
documents
(including AND)
Number of documents
(not including AND)
Scopus
22 24
Web of Science
4 6
ScienceDirect
12 13
ProQuest (social
science)
6 6
Google Scholar
302 341
Total
346 390
*Search date was 28 April 2018.

22
Table 2. Final database of publications included in this systematic review (n=45).
Authors
Main city / country covered in article
Year
Olea, R.
San Francisco / USA
1995
Cervero, R.
Seoul/ South Korea
2000
Tajima, K.
Boston, San Francisco / USA
2003
Masenten, D. J.
Boston, San Francisco, Portland, Milwaukee, Seattle / USA
Toronto/ Canada
Seoul/ South Korea
2004
Cervero, R.,
San Francisco, Portland, Milwaukee / USA
Seoul/ South Korea
2006
Hastrup, S.
San Francisco / USA
2006
Henderson J.,
San Francisco / USA
2007
Napolitan F.,
Zegras P.C.
San Francisco, Milwaukee / USA
2008
Cervero, R.
San Francisco, Portland, Milwaukee / USA
Seoul/ South Korea
2009
Cervero, R.,
Kang, J., Shively,
K.
San Francisco, Boston, Portland, Milwaukee / USA
Seoul/ South Korea
2009
Henry, K.T.
Boston, Milwaukee, San Francisco, Oakland / USA
2009
Kang, C.D.
Seoul/ South Korea
Paris/ France
Niagara Falls, New York, Milwaukee, San Francisco,
Portland/ USA
2009
Kang, C. D.,
Cervero, R.
Seoul/ South Korea
San Francisco, Portland, Milwaukee / USA
2009
Stephenson, K.L.
Milwaukee/ USA
2010
Lee, H.C.
San Francisco / USA
2010
Schiller P.L.,
Kenworthy J.R.
Seoul / South Korea
2010
Tumber, C.
Milwaukee / USA
2011
Renne, J.
Boston, Milwaukee, Oakland, Portland, San Francisco /
USA
Seoul/ South Korea
2011
Spicer, S.
San Francisco, New York, Oakland, Milwaukee, Portland,
Boston, Providence / USA
2011
Piatkowski, R.
Milwaukee, Portland, New York, San Francisco / USA
Seoul/ South Korea
2011
Billings, J.
Portland, New York, Chattanooga, Milwaukee, Boston, San
Francisco/ USA
Toronto/ Canada
Paris/ France
Birmingham/ England
Madrid / Spain
Seoul/ South Korea
2011
Newman, P.,
Hargroves,
Boston, San Francisco/ USA
Seoul/ South Korea
2012

23
Authors
Main city / country covered in article
Year
C.,Desha, C.,
Matan, A.,
Whistler, L., Farr,
A., Wilson, K.,
Kumar, A.
Giordano, J
Milwaukee, Portland, San Francisco / USA
Paris/ France
Seoul/ South Korea
2012
Rose M.H., Mohl
R.A.
Milwaukee, Portland, New York, Boston, San Francisco,
Oakland / USA
2012
DiMento J.F.C.,
Ellis C.
Boston, Portland, Chattanooga, Milwaukee, New York City,
Baltimore /USA
Madrid / Spain
2012
Billings J.,
Garrick N.W.,
Lownes N.E.
San Francisco, Milwaukee / USA
2013
Garrick, N.,
Billings, J.
Milwaukee, Portland, Chattanooga, San Francisco, New
York, Boston / USA
Seoul/ South Korea
Toronto/ Canada
Paris/ France
2013
Ladd, B.
Portland, New York, San Francisco, Oakland / USA
Paris/France
Seoul/ South Korea
2014
Henderson, Jason
San Francisco/ USA
2014
Wasserman, PC
San Francisco, Portland, Seattle, Boston, Chattanooga,
Milwaukee /USA
Madrid / Spain
Toronto/ Canada
Seoul/ South Korea
2014
Iskandar, D.A
Portland, San Francisco, Milwaukee / USA
2014
Tomlan, M.A.
Boston, San Francisco/ USA
2015
Reid, C.
Portland, Boston, San Francisco /USA
Toronto/Canada
Seoul/ South Korea
2015
Newman, P.,
Kenworthy, J.
Portland, San Francisco, Milwaukee, New York, Niagara
Falls/ USA
Seoul/ South Korea
Toronto/Canada
Paris/France
2015
Kraft-Klehm, J.
Milwaukee, Portland, New York, Boston, San Francisco/
USA
2015
Kang, C. D.
Seoul / South Korea
2016
Vanstone, L.
New York, San Francisco, Milwaukee / USA
Seoul/ South Korea
Toronto/ Canada
2016
Snyder, A.
Milwaukee, San Francisco/ USA
2016

24
Authors
Main city / country covered in article
Year
Seoul/ South Korea
Waqar, D.
Portland, San Francisco, Milwaukee /USA
2016
Woldeamanuel,
M.
Portland / USA
2016
Hitz, A.E.
San Francisco/ USA
2017
Laukkanen, M.
Portland, San Francisco/ USA
Seoul/ South Korea
2017
Redza E.,
Bouillard P.
Paris/ France
2017
Weber, J.
New York, San Francisco, Portland, Milwaukee, Seattle,
Oklahoma City, Boston, Providence, Arlington County /
USA
2018
Prytherch, D.
Portland, San Francisco, Milwaukee / USA
2018
Note: The full details are provided in the reference list at the end of this article.

25
Table 3. Number of publications by year.
Publication year
Number of publications
1995
1
2000
1
2003
1
2004
1
2006
2
2007
1
2008
1
2009
5
2010
3
2011
5
2012
4
2013
2
2014
4
2015
4
2016
5
2017
3
2018
2

26
Table 4. Publication types.
Publication Type
Number of publications
Book chapters
14
Master theses
11
PhD theses
3
Journal articles
10
Papers produced by universities
4
Conference proceeding
1
International symposium
1
Seminar paper
1

27
Appendix A1. Freeway removal projects in the United States.
City/state/coun
try
Freeway
name
Design
feature
Year
built
Remov
al date
Original
length
(km)
Removal
length
(km)
Removal reason
Substitute project
Portland,
Oregon, USA
Harbor
Drive
At grade
1942
1978
4.9
4.9
Anti-freeway sentiment; Urban
redevelopment (urban decline);
Power structure support;
Local communities demand; Air
pollution;
Economic development;
Reduce traffic congestion;
Alternative route construction;
Academic association support;
Surface boulevard;
Public recreational
space (waterfront
park);
New York
City,
Manhattan,
USA
West Side
Highway
Elevated
1929
1989
8.3
7.7
Anti-freeway sentiment; Safety
concerns; Financial concerns;
Structural damage; Power structure
support;
Local communities
demand;
Academic association
support;
Surface boulevard;
Public recreational
space (waterfront
park);
Bike lane;
Landscape median;
Oakland,
California,
USA
Cypress
Freeway
Elevated
1955
1998
4.9
2.5
Earthquake; Structural damage;
Safety concerns; Financial
concerns; Political ideology;
Business enterprises support;
Surface boulevard;

28
City/state/coun
try
Freeway
name
Design
feature
Year
built
Remov
al date
Original
length
(km)
Removal
length
(km)
Removal reason
Substitute project
San Francisco,
California,
USA
Embarcad
ero
Freeway
Elevated
1953
2001
2.6
2.6
Earthquake; Structural damage;
Local coalition of professional
Association; Local communities
demand (homeowners,
neighbourhood ); Political ideology;
Power s
tructure support; Safety
concerns; Mobility value decreased;
Business Enterprises support;
Financial Concerns; Academic
association support;
Surface boulevard;
Sidewalk; Bike lane;
Public amenities;
Niagara Falls,
New York,
USA
Robert
Moses
Parkway
At grade
1961
2001
29
10.5 km
of the
freeway
reduced
from 4 to
2 lane
Urban redevelopment; Reduce
physical obstacle; Power structure
support; Local communities
demand;
Academic association
support;
Sidewalk; Bike lane;
Reduced lanes(two
lane road);
Arlington
County,
Virginia, USA
VA 110
Unknow
n
1940
s
2004
3.88
1.3
Security concerns;
Provide a larger
security buffer zone
for the Pentagon
building;
San Francisco,
California,
USA
Central
Freeway
Elevated
1959
2005
2.9
1
Temporary shutdown; Economic
development; Existence of
precedents;
Earthquake; Structural damage;
Local coalition of professional
Association; local communities
demand (homeowners,
neighbourhood); Political ideology;
Safety concerns; Mobility value
Surface boulevard;
Sidewalk; Bike lane;
Landscape median;

29
City/state/coun
try
Freeway
name
Design
feature
Year
built
Remov
al date
Original
length
(km)
Removal
length
(km)
Removal reason
Substitute project
decreased; Academic association
support;
Chattanooga,
Tennessee,
USA
Riverfront
Parkway
At-grade
1960
s
2005
4 lane
Reduced
to 2lane
Underutilized (low traffic volume,
f
reeway did not served initial
purpose)
; Urban redevelopment;
Reduce physical obstacle;
Economic
development; Air
pollution
; Financial concerns;
Public benefit;
Sidewalk; Reduced
lanes (two lane
road); Four at-grade
intersections;
Boston,
Massachusetts,
USA
Central
Artery
Elevated
1950
s
2007
5.7
4
Anti-freeway sentiment; Design
flaws; Reduce
traffic Congestion;
Future safety concerns
; Business
Enterprises support; Power structure
support; Additional urban space
needed ;
Surface boulevard;
Public recreational
space (parks);
Underground tunnel
(big dig);

30
City/state/coun
try
Freeway
name
Design
feature
Year
built
Remov
al date
Original
length
(km)
Removal
length
(km)
Removal reason
Substitute project
Milwaukee,
Wisconsin,
USA
Park East
Freeway
Elevated
1969
2009
1.6
1.6
Political ideology (mayor);
Power structure support;
Anti-
freeway sentiment; Financial
concerns (major costs to renovate);
Urban r
edevelopment (mixed use
community success ); Reduce
physical obstacle; Underutilized
(low traffic volume);
Future safety
concerns; Mobility value decreased;
Business Enterprises support;
Economic development; Structure
aging; Local communities demand;
Academic association support;
Structural damage;
Surface boulevard;
Sidewalk;
Landscape median;
New residential
developments (new
neighborhoods);
Providence,
Rhode Island,
USA
Interstate-
195
Expresswa
y
Elevated
1950
s
2010
8.1
2
Relocation; Urban redevelopment;
Structure aging; Financial concerns;
Sidewalk (bridge);
Public recreational
space (parks); Bike
Lane (bridge);New
residential
developments (new
homes);
Seattle,
Washington,
USA
Alaskan
Way
Viaduct
Elevated
1953
2011
4.6
4.6
Earthquake; Structural damage;
Safety concerns; Financial concerns
;
Surface boulevard;
Public recreational
space (waterfront
park); Underground
tunnel;

31
City/state/coun
try
Freeway
name
Design
feature
Year
built
Remov
al date
Original
length
(km)
Removal
length
(km)
Removal reason
Substitute project
Oklahoma
City,
Oklahoma,
USA
Crosstown
Expresswa
y
Elevated
1960
s
2012
8
7.3
Structure aging; Future safety
concerns; Financial concerns;
Relocation;
Surface boulevard;
Baltimore,
Maryland,
USA
East–west
Expresswa
y
Elevated
1966
2012
2.3
2.3
Public benefit; Urban
redevelopment;
Public transport
facilities; Parking
lots;

32
Appendix A2. Freeway removal projects outside the United States.
City/count
ry
Freeway name
Design
feature
Year
built
Remov
al date
Original
length
Removal
length
Removal reason
Substitute project
Paris/
France
Georges
Pompidou
Expressway
At-grade
1967
2002
1
12.9
7
Power structure support (Mayor);
Political ideology; Urban
redevelopment; Reduce physical
obstacle; Waterfront rehabilitation;
Public benefit (p
ublic space
creation);
Economic development;
Touristic activities; Environmental
concerns; Reduce traffic congestion;
Academic association support;
Sidewalk; Public
recreational space;
Bike lane; Bus lanes;
Taxi lanes; Tramway
line;
Toronto,
Ontario,
Canada
Gardiner
Expressway
East
Elevated
1956
2002
18
1.3
Underutilized (freeway did not
served initial purpose)
; Waterfront
rehabilitation; Urban
redevelopment; Reduce physical
obstacle; Financial concerns; Power
structure support; Academic
association support; Transferal of
responsibility between regularity
bodies;
Surface boulevard;
Sidewalk; Bike lane;
1 The freeway was closed to traffic temporarily in 2002 and permanently in 2012.

33
City/count
ry
Freeway name
Design
feature
Year
built
Remov
al date
Original
length
Removal
length
Removal reason
Substitute project
Birmingha
m,
England
Masshouse
Circus
Elevated
1960
s
2003
3.2
3.2
Urban redevelopment; Reduce
physical obstacle;
Public benefit
(better pedestrian access);
Surface boulevard;
Seoul/Sout
h Korea
Cheonggyeche
on Expressway
Elevated
1958
2005
13
9.4
Power structure support (Mayor);
Political ideology;
Future safety
concerns
; Structural damage (need
structural repair); Waterfront
rehabilitation; Public benefit (public
space creation); Financial concerns;
Urban redevelopment; Reduce
traffic congestion;
Air pollution;
Noise pollution; Structure aging;
Environmental concerns; Academic
association support; Reduce
decentralization and
suburbanization;
Public recreational
space; Bus lanes;
Madrid/Sp
ain
M-30
Elevated
1970
s
2011
99
10
Air pollution; Reduce traffic
congestion; Structural damage (need
structural repair); Reduce physical
obstacle; Urban redevelopment;
Waterfront rehabilitation;
Environmental concerns; Public
benefit (public space creation);
Sidewalk; Public
recreational space;
Bike lane;
Underground
tunnels;

34
Notes
1 In most European cities, widening and straightening old narrow streets required demolition of large section of
built environment which was resisted by local residents. Thus, in contrast to United States, many large European
cities do not have major traffic arteries or freeways running into the heart of their downtown areas (Downs, A.
2004).
2 The term ‘freeway’ is used consistently throughout this article to encompass highways, motorways, limited
access highways, elevated highways, and freeways.
3 While freeways that dissect cities are the most detrimental, freeways linking urban peripheries to airports or
bypass ring freeways that circumscribe cities are less damaging, and may be necessary in some cases. Also, the
role of freeways cannot be completely discounted as they serve cargo and freight functions too.
4 The final core Boolean search was as follows: (“freeway removal” OR “highway removal” OR “expressway
removal” OR “motorway removal” OR “ring road removal” OR “freeway teardown” OR “highway teardown”
OR “expressway teardown” OR “motorway teardown” OR “ring road teardown” OR “freeway demolition” OR
“highway demolition” OR “expressway demolition” OR “motorway demolition” OR “ring road demolition” OR
“freeway destruction” OR “highway destruction” OR “expressway destruction” OR “motorway destruction” OR
“ring road destruction” OR “freeway deletion” OR “highway deletion” OR “expressway deletion” OR “motorway
deletion” OR “ring road deletion”) AND (city* OR metropolitan* OR town* OR metropolis* OR municipality*
OR urban* OR “urban area”). To confirm that all the pertinent literature was captured, the search was conducted
once again without including (city* OR metropolitan* OR town* OR metropolis* OR municipality* OR urban*
OR “urban area”). This returned an additional 44 papers (mostly of which were deemed irrelevant to the aims of
the present study).
5 While the removal of several hundred meters could result in a marked impact to the local environment, our
experience suggests there would be insufficient documentations for such cases making comparison to those
included in the paper problematic. For verification purposes, we re-conducted the search, and indeed no papers
documenting freeway removals of less than half a kilometre were returned.
6 It is possible that we have underestimated this figure given that we did not include non-English papers and more
recent cases.
7 There may be studies on freeway removal in languages other than English which are not included here.
8 Where sources reported different removal lengths and dates, the maximum length and earliest removal date was
used in this study.