American Association of
State Highway and Transportation Officials
Special Committee on Research and Innovation
FY2023 NCHRP PROBLEM STATEMENT
Problem Number: 2023-B-06
Lower-income people and Black, Indigenous and people of color
(BIPOC) experience disproportionate levels of pedestrian crashes, injuries and
fatalities. Although there is limited data on bicycle injury and fatality
disparities, initial research suggests there may be disparities in both safety
outcomes and in access to safe and comfortable bicycling facilities. There is a
need for further data and analysis on exposure to unsafe conditions, such as
high-speed and high-volume arterials, and access to safe facilities, including
the differences in access based on income versus race. On the pedestrian side,
this would include access to safe and convenient crossings, sidewalks, street
lighting, and safe access to transit. On the bike side, this includes
comfortable, well-marked routes, crossings, separated facilities or other
low-stress facilities.
Disparate exposure does not end at traffic safety. An
environmental factor to consider is exposure to harmful air pollution. Racial
bias, whether explicit or implicit, could also play a role in pedestrian and
bicycle safety, impacting decisions regarding whether to or where to walk or
bike. Additionally, there is research to suggest that implicit racial bias may
result in reduced yielding to BIPOC pedestrians (Goddard et al., 2015;
Coughenour et al., 2020), which poses both a direct threat to pedestrians via
the immediate non-yielding activity, as well as an indirect threat in that it
may reduce safe crossing opportunities and promote unsafe crossing decisions. Finally,
there is also a need to better understand the role of underreporting of
pedestrians and bicycle exposure and crashes for certain groups, and how that
might affect our understanding of pedestrian and bicycling safety disparities.
Further analysis is needed to expand our understanding of the
various ways that lower-income and BIPOC people walking, bicycling, and rolling
face disproportionate safety threats. To be successful, that analysis requires
a full understanding of strengths, limitations, gaps, and biases of existing
data sources, a pathway to improved data practices (including demographic data
on safety outcomes), and improved methods of incorporating data on exposure,
access to safe facilities, to the direct or indirect effects of bias into safety
analyses.
Numerous studies have found an inverse relationship between
socioeconomic status and pedestrian injury and fatality risk (e.g., Stoker et
al., 2015; Chakravarthy et al., 2010; Guerra et al., 2019; Jermprapai &
Srinivasan, 2014; Maciag, 2014; Wier et al., 2009). Black or African American
pedestrians and American Indian and Alaska Native pedestrians are more likely
to be struck and killed while walking than the overall U.S. rate (GHSA, 2021;
Zaccaro et al., 2019). A national study employing data from FHWA, NHTSA, EPA,
and the Census Bureau to assess connections between the transportation system,
the built environment, and pedestrian fatalities (Mansfield et al., 2018) found
strong associations between fatalities and traffic levels on
“non-access-controlled principal arterials in urban areas as well as employment
density in the retail sectors in urban and rural contexts.” Further research is
needed to understand the relationship between these types of areas and factors
such as race and income. That study also noted that using different models for
urban and rural areas was necessary.
A national study on equity and active transportation in U.S.
cities found that non-white people and those with lower socio-economic status may
actually have access to more “walkable” environments using a simple metric of
density and connectivity, while having access to fewer bike lanes (Braun,
2018). In contrast, a 2012 national study based on walkability audits of over
10,000 street segments in a nationally representative sample of over 150 U.S.
communities, found that “people living in low-income communities are less
likely to encounter sidewalks, street/sidewalk lighting, marked crosswalks and
traffic calming measures such as pedestrian-friendly medians, traffic islands,
curb extensions and traffic circles” (Gibbs et al., 2012). However, the study
does not take into account pedestrian injury risk factors, including exposure
and road characteristics.
Mansfield et al. (2018) noted that better pedestrian
activity/exposure data is needed, as pedestrian volumes are not tracked
systematically on a wide scale (e.g., across states or nationally). Pedestrian
backdrop characteristics, including sidewalks and crossings, are not available
nationally, or even in many regions. Further non-fatal injury data is not
tracked in a consistent way. Examples of crash types that are less likely to
appear in police records include minor or property damage-only crashes, in
which case police are never notified (Imprialou & Quddus, 2019); pedestrian
crashes outside the roadway, which may include people walking next to the road
(Tarko & Azam, 2011); and crashes not involving motor vehicles (Doggett et
al., 2018; Medury et al., 2019).
There is some evidence of disproportionate underreporting of
pedestrian crashes for certain groups, such as Black men (Sciortino et al.,
2005). However, most studies that have found underreporting of pedestrian and
bicycle crashes have not looked at whether such crashes were more likely to involve
lower-income or BIPOC pedestrians or bicyclists. Further, there is limited
analysis of the impact of such underreporting on our understanding of safety
disparities.
While there is evidence of bias in yielding to pedestrians
(Goddard et al., 2015; Coughenour et al., 2020), it is not clear what impact
this bias has on route choice and exposure, risk-taking, or safety outcomes.
Other gaps in the research include separating out the impact of race and income
in terms of exposure to traffic and air pollution exposure, as well as safety
outcomes.
This research should coordinate closely with:
·
NCHRP
08-150 “Valuation of Transportation Equity in Active Transportation and Safety
Investments,” which is anticipated to begin in 2021-22. The project will likely
“develop data driven tools and guidelines for use by practitioners in safety
decision making and in supporting Safe System principles.” Although 08-150 will
focus more on developing tools for practitioners to use, and the proposed
research focuses on evaluating and improving data sources and analysis methods
to understand demographic disparities, there is an opportunity to coordinate
closely on assessing and applying data.
·
FHWA
is likely to fund a project on “Exploring Race, Ethnicity, and Socio-Economic
factors for Pedestrian and Bicyclist Morbidity and Mortality.” The project is
likely to identify crash types that BIPOC pedestrians and bicyclists are
overrepresented in, and propose countermeasures, guidance, and materials to
address those disparities. The proposed research would be a valuable input, and
coordination would benefit both projects.
·
In
July 2021, BTSCRP announced an anticipated project on “Equity in Pedestrian and
Bicyclist Mobility, Safety, and Health: The Impact of Racial Bias” (BTS-21).
The objective focuses on racial disparities in policing.
Other projects or potential projects to coordinate with
include:
·
TRB Circular E-C270 includes Problem Statements
C2: Identify the causes of racial disparities in traffic safety and C3:
Understand bias in traffic and transit enforcement and implications for
minority communities.
·
Understanding
Pedestrian Crash Injury and Social Equity Disparities in Oregon (ODOT SPR 841),
which is applying an ecological analysis approach to pedestrian crash
disparities in Oregon, and findings and methods could inform the proposed
research.
·
The TRB Pedestrians committee has developed a
Research Needs Statement on “Documenting the Impact of Racial Bias in Policing
and Evaluating Alternative Approaches to Advance Equity in Pedestrians’ and
Bicyclists’ Mobility, Safety, and Health.” The statement is likely to be
submitted for a BTSCRP topic. If funded, this would be a valuable input into
the proposed research.
·
The TRB Bicycle committee has developed a
Research Needs Statement on “Social Equity in Pedestrian Collision Trends,
Reporting and Decision Making.” https://rns.trb.org/details/dproject.aspx?n=43252
This research would aim to clarify the strengths and gaps of
existing data for understanding active transportation safety equity
implications, propose improvements to data collection practices, and improve
the application of available data and modeling. A better understanding of what
available data can and cannot tell us about safety disparities is an important
step before we can understand and act most effectively to reduce and eliminate
disparities. The products of this project include a document proposing
improvements to data collection practices, and a research report detailing
improved methods of assessing and understanding disparities.
This research should seek to disentangle disparities by both
race and income, since it is likely that disparities would be different between
distinct demographic groups. The research should also assess urban, suburban
and rural areas separately, so as not to entangle the effects of urban context
with race or income effects. All aspects of the research should also examine
walking and bicycling separately, recognizing both the commonalities and
differences between the modes.
Phase 1 of the research would focus on documenting available
data, current data applications, and proposing updates to data collection and
application processes to be utilized in assessing pedestrian and bicycle safety
disparities.
1)
Coordinate
with NCHRP 8-150 to comprehensively document availability, strengths and
weaknesses, of sociodemographic data in:
a.
Pedestrian
and bicycle exposure data, including by location of activity (e.g., to assess
exposure on high-speed, high-volume arterials, or on other facilities that may
be unsafe).
b.
The
availability of and access to safe countermeasures, including crosswalks,
sidewalks, lighting, traffic calming, bicycle infrastructure, etc.
c.
Crash
data, including fatal, injury and non-injury crashes.
2)
Conduct
a systematic assessment of potential/likely bias and/or underreporting of
pedestrian and bicycle exposure, activity, and crashes.
3)
Document
current practices to deploy available data for active transportation safety
equity assessments, including any efforts to overcome or correct for data gaps.
Phase 2 of the research would focus on understanding the extent
and causes of active transportation safety disparities.
4)
Using
data and outputs from Phase I, estimate the extent of racial and economic
safety disparities in walking and in bicycling nationally and in different
contexts (e.g., urban, suburban, rural) as well as specific land use/context
data. The assessment should seek to use the best available data and modeling
methods; knowledge about the limits, potential bias, and underreporting; and
illustrate proxy data, methodological adjustments, and limitations. The
analysis would explicitly address uncertainties in estimates due to data
limitations. These findings would help inform recommendations on improvements
to data collection.
5)
Conduct
a literature review on the causes of racial disparities in active transportation
safety and the impact that these causes (including racial biases) and
disparities may have on decisions about whether and where to walk or bike.
6)
Based
on gaps in the existing research, conduct new research to better understand the
causes of safety disparities in walking and bicycling. The causes would
include, but not be limited to, differences in exposure, access to safe
infrastructure, and driver and other racial biases. This research may rely on
some existing data and may involve the collection of new data.
The project will culminate in the development of two
products:
7)
Identification
of best practices and policies to improve active transportation safety data to
overcome safety data gaps identified in steps 1-3.
8)
A
research report documenting the following:
a.
Strengths,
weaknesses, and application of current active transportation safety data
sources for assessing disparities;
b.
Research
and analysis methods used in the project;
c.
An
estimate of the extent of racial and economic safety disparities in active
transportation; and
d.
An
assessment of the causes of disparities, including racial bias.
While there is clear evidence of some key disparities in
active transportation safety, existing data and data applications limit the
ability to understand the extent of safety disparities, differences by specific
sociodemographic groups, and causes of disparities.
Better data and understanding of how to analyze active
transportation safety disparities is a key step in acting to address causes and
promote investment in targeted safety programs and infrastructure, and inform
policies to improve bicycle and pedestrian data and safety in disadvantaged
areas.
State DOT safety officials can utilize the report findings to
work with DMVs, state and local police, and hospitals to improve active
transportation crash and injury reporting.
Research findings can be used by state and local planners to
assess exposure to dangerous transportation/roadway environments, and access to
safe facilities, by race and income, in urban, suburban and rural contexts. The
research would be used to improve data collection practices, conduct safety
analyses, target investments in walking and bicycling infrastructure, and to
develop safety policies and plans. Analysis methods related to ecological
assessment of risk for people walking and bicycling based on exposure,
environment, and access to facilities, could be deployed at state, regional or
local levels.
Follow-up research could develop strategies to deploy
countermeasures to reduce disparities in safety outcomes, access to safe
facilities and activity levels, and then test the strategies. Inform future
research to explore the causes or contributors to disparities revealed in this
project, as well as evaluations of policies and investments seeking to address
disparities.
$750,000
36 months
Nathan McNeil, Portland State University
Jennifer Dill, Portland State University
Stefanie Brodie, Toole Design Group
AASHTO Council on Active Transportation
Toks Omishakin, Caltrans Director, and
Chair, Council on Active Transportation
Braun, L. M. (2018). Geographies
of (dis)advantage in walking and cycling: Perspectives on equity and social
justice in planning for active transportation in U.S. cities [Doctor of
Philosophy in the Department of City and Regional Planning]. University of
North Carolina.
Chakravarthy, B., Anderson, C. L., Ludlow, J., Lotfipour, S.,
& Vaca, F. E. (2010). The Relationship of Pedestrian Injuries to
Socioeconomic Characteristics in a Large Southern California County. Traffic Injury Prevention, 11(5),
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Coughenour, C., Abelar, J., Pharr, J., Chien, L.-C., &
Singh, A. (2020). Estimated car cost as a predictor of driver yielding
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Guerra, E., Dong, X., & Kondo, M.
(2019). Do Denser Neighborhoods Have Safer Streets? Population
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