Research from Denver and San Francisco indicate that traffic on one-way streets is more intimidating than on two-way streets, and that neighbourhood interaction declines as traffic increases.
By Sarah V. Wayland
Published June 07, 2012
During the current debate on one-way streets in Hamilton, many people have asked for "evidence" and "hard data" on the impact of one-way and two-way streets. My own search of scholarly periodicals and other documents turned up very few empirical studies that specifically focus on the impact of one way streets on neighbourhoods, businesses, traffic, and the like.
Interestingly, much of this very small body of literature was written in the 1970s and 1980s, likely alongside growing interest in the impact of the many one-way arterial routes installed in the previous decades.
In a previous article, I presented research findings on the impact of one-way streets on retail businesses. In this article, I focus on neighbourhoods and quality of life on one-way streets and streets with heavy traffic.
In 1984, in response to longstanding complaints by residents of neighbourhoods flanked by one way streets, the Denver Planning Department commissioned a study to look into how to mitigate negative impacts of one-way streets in neighbourhoods.
Bernie Jones, of the University of Colorado at Denver and member of the citizen's advisory committee for the study, led a household survey as part of the study, the results of which were published in a peer-reviewed journal.1
His team conducted face to face interviews with 232 residents of the same neighbourhood, some of whom lived on one-way streets and some on two-way streets. Most of the streets in question contained two lanes of traffic, but some carried up to five lanes.
Respondents were asked for their views on the neighourhood; use of the outdoor area around the home; experiences with and responses to traffic; and desired changes in the neighborhood. None of the survey participants were directly asked about living on one- or two-way streets, and interviewers were instructed not to bring up the topic.
Adult respondents came from a variety of age groups, marital status, household sizes, income levels, and occupations. They also occupied different housing types, from single family homes to high-rise apartments.
The findings found that residents of one-way streets were significantly more bothered by traffic. Proportionally, almost three times as many residents of "one ways" indicated that traffic on their street was a problem, and also that their block was dangerous.
Also, those living on one ways were less likely to greet a large number of neighbours. Residents of one-way streets were less satisfied with their blocks overall, including because their environment was noisy.
People living on "one ways" made adjustments to their lifestyles: they were less likely to sit out front, more likely to install buffers to the street such as landscaping, more likely to prevent their children from playing out front, and they were more likely to rearrange their living space to get away from street noise.
In an open-ended question asking what would make their neighbourhood a nicer place to live (with no prompting as to possible answers), 1 in 3 respondents of "one ways" mentioned a conversion to two-way streets. More than half of the changes called for related to traffic, compared to only 13% of the responses from persons living on two-way streets.
In the words of the author:
One-way street residents were significantly more bothered by traffic (noise, volume, danger), less satisfied with their block (cleanliness, peacefulness, air quality), and therefore made more life-style adjustments (less use of front of house, rearranging use of rooms, installing buffers). Consequently, more one-way street residents wanted a traffic change on their block. On a number of measures (e.g., economic conditions, neighboring, stability) no differences were found. These mixed results are read as confirmation that one-way arterials do have some of the suspected negative impacts but also that many people accommodate and resign themselves to the situation.2
Also cited in Jones article (though not available for examination first-hand) is the other data produced by the Denver Planning Office in the 1980s. The Planning Office documented a number of negative effects along one-way streets, including:
The author cites an earlier social impact study in San Jose, CA in which one way to two way conversion was the topic. According to the author: "Negative impacts of the one-ways were documented for noise, real estate values, and air quality."3
As a result of this research, in 1987, Denver city planners worked to convert some one-way streets to two way.
The Denver research echoes the findings of Donald Appleyard, who conducted a study in 1970s to determine how the level of traffic impacted residents.4
He compared three residential streets in San Francisco that were deemed identical except for their levels of traffic. Light Street carried 2,000 vehicles per day. Medium Street carried 8,000 vehicles per day. Heavy Street carried 16,000 vehicles per day.
People living on Light Street reported having three times more friends and twice as many acquaintances of their streets as those on Heavy Street.
Appleyard connected this dramatic differences to peoples' feelings about their "home territory." When asked people to draw their "home territory" on a map, those on Heavy Street never marked the road as part of it, and few marked anything beyond their own front yard.
In contrast, residents of Light Street marked out an area that covered the street and both sidewalks. As speed and traffic increased, the space that people considered "home territory" shrank.
Appleyard concluded that the influence of traffic goes beyond the physical space it occupied. Rather, traffic has a "zone of influence" that intimidates and takes over psychological space. As traffic grew, the interaction among neighbours declined, as did community space.
Whereas the sidewalk was a space for socializing and playing on Light Street, on Heavy Street people not only retreated into their own homes, but many of them even abandoned the front rooms of their residences due to traffic noise. In some cases, people abandoned their homes altogether, or treated them as transient spaces not conducive to developing social networks.
These two studies had addressed somewhat different concerns but had complementary findings. In both cases, higher levels of traffic impacted residents adversely.
Though the second study did not address one-way streets specifically, its findings indicate that the kind of one-way thoroughfares we have in downtown Hamilton inhibit residents from developing connections with neighbours and feeling a sense of attachment to the community. It also indicates that people who live along these streets are more likely to do so out of necessity than choice - who would actually choose to live along such a busy street?!
There are different options for reducing and slowing traffic flows on Hamilton's arterial boulevards, including conversion to two-way, street narrowing, and the like. That debate will continue. What this article shows, albeit with a small pool of research findings, is that motor vehicle traffic does adversely impact residents and neighbourhoods. Let's all agree on that, and move forward.
I think the current debate in Hamilton is emblematic of a broader clash of values. The creation of one-way highways through cities in the postwar era emphasized the values of individualism and mobility, a sort of "I need to get somewhere and want to get there as quickly as possible" mentality.
In contrast, residents of urban neighbourhoods often prefer the values of community and sustainability, and these voices are starting to be heard in Hamilton again.
We are witnessing a resurgence of community values, a better understanding of what constitutes a desirable neighbourhood and city, and the value of history in informing and shaping our present understanding of the city.
1. Bernie Jones, One Way to Neighborhood Deterioration? Journal of Planning Education and Research (April 1986): 154-163.
2. ibid., p. 154.
3. ibid., p. 156.
4. Donald Appleyard, Livable Streets (Berkeley: University of California Press, 1981).