The preponderance of evidence indicates that high vehicle
speeds cause traffic deaths, particularly pedestrian deaths.
Leaf and Preusser, in their 1999 review of the literature conducted
for the National Highway Traffic Safety Administration,
find that higher vehicle speeds are strongly associated
with both greater likelihood of crash occurrence and
greater severity of pedestrian injury. Leaf and Preusser analyze
a database of over 23,000 pedestrian-involved crashes
where the police report contained an officer’s estimate of
the pre-crash vehicle speed (1999). Figure 2 shows the
stark correlation between vehicle speed and the likelihood
that a pedestrian will be killed. In 122 U.S. counties, Lambert
and Meyer found that speed limits significantly correlate
with rates of fatal pedestrian crashes (2006).
Several studies find a correlation between residential street
width and traffic fatalities. Swift et. al. conducted regression
analyses on 20,000 crash records from Longmont, Colorado
(Swift, Painter, and Goldstein, 1997). After eliminating
crashes where some significant factor aside from street
design probably caused the crash (i.e. snow or icy conditions,
drunk driving), they examine physical street design
features at each crash location. They find that the number
of crashes per mile of street per year rises exponentially
with the width of the street. Moreover, street width explains
73% of the variation in crash rates. The study concluded
that 36-foot wide streets have 485% more injury collisions
than 24-foot wide streets. However, in their analysis of pedestrian
fatality and serious injury crashes in Florida, Leaf
and Preusser (1999) found that roadway width is unrelated to the speed of striking vehicles. The relationship between width and increased crashes may be uniquely strong for residential streets. It may also be mediated through variablesother than speed.
Due to the safety problems with wide and fast streets, both
real and perceived, these streets are less conducive to walking,
bicycling, using a wheelchair, skateboarding and other
modes of active transportation. A body of public health
research links rapidly rising rates of obesity to a built environment
that discourages active transportation. Numerous
surveys conducted by pollsters (Gallup, 2008; Harris, 1991),
cities, and consultants routinely find that the primary factors
that prevent people from bicycling and walking more
are the lack of safe streets, sidewalks, and street crossings.
In order to entice more people to walk, bicycle or wheel, we
have to make our streets safer. Much of making our streets
safer relates to slowing vehicle speeds.
Transportation consumes 28% of the energy used in the
United States, with most of this consumption being due to motor vehicle use (US Energy Information Administration,
2012). Making walking, bicycling and transit more attractive
could significantly curtail transportation-related energy
use. According to the National Household Travel Survey (Federal
Highway Administration, 2009) 39% of personal trips
in US metropolitan areas are less than 3 miles long, and
17% are less than 1 mile. Yet 47% of all trips less than 1 mile
and 69% of trips less than 3 miles are taken by car. A great
opportunity exists to enable people to choose to walk and
bike for these short trips. Research indicates that improvements
in street design to make walking and bicycling safer
and more convenient result in more people walking and
biking (Pucher and Buehler, 2012). Furthermore, most transit
trips begin with a walking or bicycling trip. Making the
trip to the bus stop or transit station safer and more attractive
by walking or bicycling would encourage transit use.
Motor vehicles produce large amounts of air pollution as
well as greenhouse gases (GHG). Of GHG emissions in the
US, 28% come from the transportation sector (US Department
of Transportation, 2006). Making walking, bicycling
and transit more attractive could significantly reduce transportation-related
GHG emissions.
Street design impacts our economy in several ways. First,
wide streets are more expensive to construct and maintain
than narrower streets since they have more surface to pave
and maintain. Second, wide streets and multi-lane streets
create higher speeds and reduce the likelihood that motorists
will stop (Rosales, 2006), which impedes pedestrian
access to businesses along these streets. Retail streets that
are easy for pedestrians to cross effectively bring all of the
stores and restaurants closer to shoppers, making it more
likely they will patronize them. Third, enabling more people
to walk, cycle and take transit can save households the
money they spend on daily transportation. The average
household in the Los Angeles-Long Beach-Santa Ana Metropolitan Statistical Area spent $12,154 per year on transportation between 2005 and 2009 (Center for Neighborhood Technology, 2012).
Streets with less traffic and slower traffic enable people to
interact more. Research conducted by (Appleyard, 1981)
showed a distinct correlation between traffic volumes and
the number of acquaintances people have. The research
showed that people had more friends and more contact
with their neighbors on streets with less traffic than those
with more.
Narrower and slower streets create more livable communities
than wide, high-speed streets (Rosales, 2006). In
neighborhoods where children can safely walk to school, to
the park or to visit friends, children grow up more independently
and place fewer burdens on their parents to transport
them. Many older adults don’t drive and walk slowly.
When they can cross streets and walk to the store, dry
cleaners, doctor’s office, friends’ homes, parks or places of
worship, they experience healthier and more independent
lives.
Building streets for speed compromises our humanity.
Where streets are built at a human scale, people have higher
quality of life than along streets built for vehicle movement.
Excerpt from a 2013 report entitled “Best Practices: Emergency Access in Healthy Streets.”
Keywords: safety, alt transit, pedestrian’s rights, traffic flow, city planning, tactical urbanism, urban walkability, greenhouse gas emissions
