American
Association of State Highway and Transportation Officials
Special
Committee on Research and Innovation
FY2023
NCHRP PROBLEM STATEMENT TEMPLATE
Problem
Number: 2023-G-05
Problem Title
Integrated Strategies for Managing High Travel Speeds
Background
Information and Need For Research
High traffic speeds are arguably the largest contributor
to traffic deaths in the United States. High speeds contribute to crash
occurrence and their direct influence on impact speeds determine crash
severities (Aarts & van Schagen, 2006; Hussain et al, 2018). Moreover,
specific populations, i.e., traditionally marginalized, and underserved
communities, bear a disproportionate burden of our collective traffic injury
problem (Hamann, Peek-Asa, & Butcher, 2020). Despite the existence of isolated
interventions to curtail higher speeds—e.g., speed safety cameras, traffic
calming road design, concordance between land use and road classifications—few
of them have been widely and equitably adopted, and none get at the deeply
rooted and interconnected causes of the problem, such as people’s harried
lifestyles, thrill-seeking behaviors, the consumption of increasingly more
powerful vehicles, prioritizing speed over competing values of concern for self
and others, among many other interacting factors.
Literature
Search Summary
The reasons people drive at high travel speeds are
complex and often situation specific. For example, many drivers strongly
believe that most other drivers speed and that therefore, speeding must be a
normal, even expected behavior (Yannis, Louca, Vardaki, and Kanellaidis, 2013).
And as most drivers consider themselves as better than the average driver, they
tend to think that they are immune to being injured when driving at high speeds
(Mouter, van Cranenburgh, and van Wee, 2018). Furthermore, as most drivers
overestimate how much time they can save by driving at high speeds (Peer,
2010), the driving public tends to rationalize speeding, arguing that sometimes
it is necessary to drive fast (Fleiter, Lennon, and Watson, 2010). More
recently, the COVID-19 pandemic and associated dampening of commuting and
leisure travel has provided us with an “unnatural experiment” into how travel
speeds have tended to increase in response to a decrease in traffic volumes
(e.g., Lee, Porr, and Miller, 2020).
In short, driving at high speeds is often conceived as
normal, expected, not too risky, nearly always time saving, and simply
necessary in many circumstances. Therefore, it should not be surprising that
often uncoordinated education, enforcement, and engineering interventions fail
to incite lasting reductions in people driving at high speeds (Naumann et al,
2020).
To manage traffic speeds proactively and over longer
periods of time, professionals need to both recognize the complexity of this
public health issue and to broaden their repertoire of ways to address it.
Relevant here are cross-sectoral partnerships and tools to help teams of
partners to visualize the complex processes that could be driving an outcome of
interest (Arnold and Wade, 2015). To ultimately develop integrated strategies
to managing travel speeds in various contexts, teams will need to draw upon
traditional data (e.g., crashes, roadway inventory, traffic speed and volume
data, freight transport) and less traditional data (e.g., indicators of land
use density and mix; perceiving those who speed as “cool”; in-vehicle feedback
on drivers’ travel speeds; consumer trends privileging vehicles of increasing
size, weight, and horsepower; and workplace and social group “culture” and
policies surrounding high travel speeds) to consider the interacting elements
of the system that influence high travel speeds. These integrated strategies
should also be adaptable enough to contend with disruptions that could impact
travel speeds, such as global pandemics, siloed funding of disconnected parts
of the system, increased awareness of social injustices and inequities in
transportation safety and access, natural disasters, and technological
breakthroughs.
Research
Objective
As mentioned, there are several efficacious
speed-reducing tools (e.g., speed safety cameras, traffic calming road design,
concordance between land use and road classifications), yet these are often not
widely or equitably applied, and none address the complex array of reasons that
people drive at high speeds. For example, traffic calmed streets can reduce
operating speeds, however, they fail to make people feel less hurried in their
lives. This research would build upon a foundation of work focused on speed
limit setting (e.g., NCHRP Research Report 966; NCHRP 17-79), street redesign,
traffic signal coordination, and automated speed enforcement toward enhancing
pedestrian safety (e.g., NCHRP Synthesis 535) to examine the confluence of
factors that influence travel speeds. This research would bring to bear a
package of promising practices (e.g., speed limit setting, land use, workplace,
congestion pricing), transportation investments (e.g., transit provision,
speed-oriented school and workplace practices), communications strategies (e.g.,
media framing of travel speeds and traffic congestion), and interventions
(e.g., intelligent speed adaptation [ISA], speed safety cameras and their
equitable placement, operation, and re-investment schemes) that can be
incorporated into a unified, adaptable framework for managing high travel
speeds. The research should also shed light on strategies that do not work, or
that may have unintended consequences to help free agencies from defaulting to
costly and ineffectual schemes and to encourage working with partners to
improve outcomes.
Research objective-related tasks could unfold over four
phases:
● The
first phase in this research project would be to synthesize a broad literature
on speed reduction strategies, as well as community-based injury reduction interventions
to expand the suite of potential strategies to expand upon in subsequent
project phases and begin to address the root causes of high travel speeds among
various road user demographic (e.g., based upon gender, race/ethnicity, income,
age) and modal groups (e.g., drivers of trucks, cars, SUVs, motorcyclists).
● In
the second phase, diverse teams of researchers, practitioners, and policymakers
would convene and engage in systems thinking exercises to generate insights on
speed-related dynamics (e.g., workplace practices that knowingly or unknowingly
incentivize high travel speeds among employees), feedbacks (e.g., sprawling
land uses that incite high speeds to cover increasingly distances), and
potential leverage points for intervention (e.g., incorporating safe design
speeds in traffic impact assessment [TIA] procedures) that will support
continued effectiveness. Combined with the literature review in the first
phase, this will provide a comprehensive and holistic view of what we know
about factors generating high travel speeds, where current interventions
attempt to intervene on the problem, weak points in these strategies, and where
we might need to consider additional interventions or supports given varying
legal, financial, and cultural contexts.
● A
third phase in this project would be to incorporate strategies identified in
the literature review and second phase into a prototype Integrated Strategies
for Speed Management Framework for managing high travel speeds in an integrated
manner that DOTs and their partners can use to manage travel speeds across the
network and within various community (e.g., schools) and institutional (e.g.,
DOTs, county public health departments, local hospitals, local news media)
environments, as well as overcoming barriers to securing funding and additional
resources to help mitigate travel speeds.
● The
fourth and final phase would draw from results of the third phase to design
prospective demonstration studies with local, regional, and state partners on
the implementation of the Integrated Strategies for Speed Management Framework.
These prospective studies would be designed to assess real-world applications
of the framework, provide tips on carrying out a formative evaluation of the
demonstration, and recommendations for refining the framework based upon
formative evaluation results. It is anticipated that this prospective
demonstration study would seek guidance on best practices for identifying
partners, policies, practices, and interventions which, when used in
appropriate contexts and in combination, can help manage travel speeds across
various spatial and time scales.
Urgency
and Potential Benefits
Road user safety is foundational to all state DOTs’
missions. As such, developing and implementing ways to curtail high travel
speeds—the largest contributor to traffic deaths in the United States through
their direct influence on impact speeds, which determine crash severities
(Aarts & van Schagen, 2006; Hussain et al, 2018)—is, or should be, a
central, organizing goal of most DOTs.
Given that more recent traffic monitoring studies have
revealed average travel speeds increasing throughout 2020, and a 7.2 percent
year-over-year increase in the number of people (38,680 in 2020) dying in motor
vehicle crashes in the US, the largest increase in fatalities since 2007
(National Highway Traffic Safety Administration, 2021), the consequences of
failing to meaningfully address the dangers of high travel speeds will result
in many more deaths and serious road injuries. Plus, the potential benefits of
attenuating high travel speeds are sizable, including reductions in deaths,
injuries, and suffering, as well as improved public health via lower ambient
noise and air pollution (Distefano, & Leonardi, 2019). To optimize the many
benefits for managing travel speeds, state DOTs and their cross-sectoral
partners would profit from more than a synthesis of existing speed management
practice, and instead engage with an expanded, coordinated set of strategies to
help address root causes and issues in speed management that are virtually
impossible to fully tackle by any single agency or strategy (e.g., solely
relying on speed safety cameras to address the problem).
The AASHTO Committee on Safety ranked this its #6
priority.
Implementation
Considerations
Considering the use of the research results from the
proposed effort, staff within state DOTs who conduct safety research, design
roadways, approve driveway permits and posted speed limits on state-owned and
operated roads, those who develop the departments’ street classifications and
cross-sectional design guides, those who work on school travel, parking, and
circulation, and administrators seeking ways of enhancing their employees’
traffic safety culture and safety performance, among others, will find results
from this research practical and readily adaptable in their workflows.
An increasing number of state DOTs are committing to
“Towards Zero Deaths” initiatives, which many recognize requires coordinated
action among multidisciplinary players who set out to solve complex road safety
problems, including the critical issue of speed management (FHWA, 2020). Thus, a few anticipated steps for state DOTs
to take to implement the proposed project’s research findings within their organizational
structures would be to consider agencies’ roles in supporting safer speeds on
our roadways, and to acquire a deeper understanding of how they can work with
partners to effectively reduce travel speeds and do so in a sustainable manner.
Processes to support adoption and implementation of the
research could take the shape of demonstration projects coupled with peer
exchanges and tailored trainings, wherein the research team partners with
several state DOTs to experiment with applying key recommendations of the
project and transmitting lessons learned to additional agencies. The project
team would likely seek assistance from the NCHRP Implementation Support Program
to carry out the following.
To foster awareness and facilitate widespread implementation
of the proposed Integrated Strategies for Managing High Travel Speeds
framework, research teams could develop brief, two-page summaries of the
project’s background, methods, results, and practical implications, and then
share the summaries via social media and through various email lists; establish
an “academy” around coordinated and innovative means of tempering travel
speeds, one that requires agencies to apply to participate, connects
participants with others to problem-solve, receive coaching, engage in systems
thinking, etc.; the demonstration projects referenced above; and accessible
multi-media (text and video) “stories” that feature academy and demonstration
project participants implementing integrated and holistic speed management
strategies, thereby demystifying the project’s complexity, and inspiring
colleagues through processes of imitation as facilitated through peer exchanges
and expert coaching.
Recommended
Research Funding and Research Period
$500,000 over 24 months.
Problem
Statement Author(S): For each author, provide their name, affiliation,
email address and phone.
Seth LaJeunesse, UNC Highway Safety Research Center,
lajeune@hsrc.unc.edu, 919-962-4236
Libby Thomas, UNC Highway Safety Research Center,
thomas@hsrc.unc.edu, 919-962-7802
Becky Naumann, UNC Injury Prevention Research Center,
rnaumann@email.unc.edu, 919-843-3530
Potential
Panel Members: For each panel member, provide their name, affiliation,
email address and phone.
Charles Brown, Equitable Cities, LLC,
charlesbrown@equitablecities.com, 908-514-9300
Barb Chamberlain, Washington State DOT,
chambba@wsdot.wa.gov, 206-716-1130
Margaret Herrera, Maricopa Association of Governments
(AZ), mherrera@azmag.gov, 602-452-5072
Amin M. Hezaveh, NCDOT, amohamado-hezaveh@ncdot.gov,
919-814-5131
Franz Loewenherz, floewenherz@bellevuewa.gov, City of
Bellevue, WA, 425-452-4077
Anusha Musunuru, Kittelson & Associates,
amusunuru@kittelson.com, 916-822-5354
Keshia Pollack-Porter, Johns Hopkins University,
kpollac1@jhu.edu, 410-502-6272
Rebecca Sanders, Safe Streets Research & Consulting,
LLC, rebecca@safestreetsresearch.com, 510-316-5940
Donald Sweezy, NYSDOT, donald.sweezy@dot.ny.gov,
518-485-8785
Person
Submitting The Problem Statement: Name, affiliation, email
address and phone.
Adnan Qazi, P.E.
Arkansas Department of Transportation
AASHTO Committee on Safety, Research Subcommittee Chair
501-569-2642
Adnan.Qazi@ardot.gov