Safe Systems in the U.S. – Finding a Path for Road Designers and Transportation Planners and Engineers
In 2001, the “Geometric Design
Practices for European Roads” scan tour report indicated that the U.S.
delegation found potentially transferable practices regarding public
involvement in project planning; self-explaining, self-enforcing rural roads;
design flexibility; area-wide traffic calming measures; intersection control
through roundabouts; and integration of bicyclists and pedestrians. Many of
these concepts have been shared across countries and the underlying philosophy
is commonly called a “safe systems” approach.
“Safe Systems” has been defined in
various ways in the transportation profession as a whole, even in the more
focused transportation safety community.
Sweden was one of the first adopters of a Safe Systems approach with its
Vision Zero program. The Safe Road
Transport System Model and the safe system definition were presented by the
Organization for Economic Co-operation and Development’s (OECD) International
Transport Forum in 2008 as: “The basic strategy of a Safe System approach is to
ensure that in the event of a crash, the impact energies remain below the
threshold likely to produce either death or serious injury.” This definition acknowledges road users make
mistakes even though for the most part, they act rationally. In the model, safe speeds represent the
primary pathway towards a safer system, and it further includes: 1) safe vehicles; 2) safe roads; and 3) safe
road users. The SUN countries, Sweden,
the United Kingdom and Norway, based their improvements in road safety at least
in part on the Safe Road Transport System model and Australia attributes its successes
to the safe system approach. These countries have outpaced the United States in
driving down traffic related deaths and are arguably “safer” than the U.S.
In the United States, The Road to
Zero and Vision Zero national initiatives promote “Safe System” principles as
the preferred path to reducing traffic fatalities in the United States. Towards Zero Deaths (TZD) includes some of
the Safe System strategies through traditional and innovative approaches
including multi-disciplinary implementation that includes safer roads,
vehicles, road users as well as safety culture. The Vision Zero Network in
particular has been aggressive about including safe system principles, most
specifically speed reduction, in its work with the more than 30 local
communities that have committed to Vision Zero since 2014. According to Vision Zero proponents, in
spite of “increased interest, little guidance exists for local transportation
planners, policy makers, public health practitioners, police and others
working” to advance the U.S. Vision Zero and its safe systems approach
(Fleisher, Wier, and Hunter, 2016.) The
same may be said for guidance to the state and national engineering, design,
and planning communities. Professionals
in the road planning, design and engineering community are faced with legacy
design processes and standards as well as legal constraints which prohibit
rapid adoption of a more aggressive approach to implementing some of the
hallmarks of Safe Systems. Many of the
Safe Systems design and operational concepts require a shift in the culture and
approach to roadway use and design including the increased consideration of all
OECD stressed in the 2008 report
that a Safe Systems approach is “the only way to achieve the vision of zero
road fatalities and serious injuries and it requires that the road system be
designed to expect and accommodate human error.” It continues that a Safe System approach is
appropriate for countries at all levels of road safety performance, with
specific interventions likely to differ from country to country. The tension to
operationalize Safe Systems approaches for use in the project delivery
processes for all projects, as well as safety countermeasure application
specifically is heightened by the undisputed and alarming increasing in traffic
related fatalities in the past several years.
Indeed, after years of decreases the number of deaths has risen from
32,744 in 2014 to 37,461 in 2017 (NHTSA, 2018.)
Transportation safety is a complex issue and a
true safe system approach must address many factors to be successful and must
be adaptable in anticipation of future change (e.g. autonomous and connected
vehicles). At a minimum these include
the role of the road user in behaving properly, vehicle design, policy and
laws, public and organizational and public cultures, etc. For Safe Systems to be fully implemented, all
of these will have to change. This
synthesis is proposed as a starting point to provide practical and effective
information for the engineering, design, and planning communities to consult
during project development and countermeasure selection processes.
A discussion among transportation
professionals in the United States revealed that there is no clear
understanding of the “Safe Systems” approach. The purpose of this proposed
research provide practitioners a clearer picture of what a “Safe Systems”
approach would involve. This research is
focused on providing data based support to the transportation engineering,
design, and planning communities to ensure when road users make inevitable
mistakes, they encounter “error tolerance” (Johansson, 2008) and as a result of
their mistakes do not experience serious injury or death. The proposed research should also be forward
thinking when evaluating current approaches in anticipation of technological
advances. The scope includes the task to identify opportunities for the road
design, planning, and engineering communities in the U.S. and abroad to
accelerate implementation of appropriate safe system infrastructure and Human
Factors interventions and countermeasures by identifying available tools and
gaps in guidance.
To help agencies achieve the Road
to Zero goal of zero deaths and serious injuries in the United States by 2050,
agencies will need to modify their processes for completing roadway projects. This
research supports the AASHTO Strategic Plan for the Committee on Safety Goal 1,
Strategy 1.1, “Lead in the Implementation of Toward Zero Deaths: A National
Strategy on Highway Safety. In an ideal world, any project concept would
include elements related to context, evaluation of operations, safety, human
factors, and public health as part of a safe transportation system. Each
iteration of the project from planning through final design would depend on
this multiple lens approach. The following questions will be investigated as
related to a Safe Systems approach.
is a Safe Systems approach in the context of developing a transportation
project and how does it differ from the current project development process?
kinds of plans and planning processes do the Safe Systems countries use?
can the U.S. planning process more effectively implement a Safe Systems
would a Safe Systems approach look in the future with technological advances
such as autonomous/connected vehicles, transportation-as-a-service, or
are the differences in various contexts (e.g. urban core, general urban,
suburban, rural, etc.)?
is the approach to design standards prevalent in countries that have adopted a
Safe Systems approach such as Sweden and Norway and can they be mapped to
current U.S. standards particularly in regard to speed management and other key
Safe System components or is a new approach recommended?
are the guidelines and policy constraints on roadway designers and operators in
Sweden or other European counties and Australia?
exists today in the way of tools that result in a Safe Systems approach in the
U.S.? Consider major design guides, NACTO, new and alternate guidelines,
context sensitive solutions, Human Factors, etc.
tools are needed in the various processes including concept, planning, data, analysis,
design, and construction?
do the Human Factors, Safety Culture, and Public Health sectors fit in with the
Safe Systems approach?
public agency policies may need to be changed/modified?
legal challenges exist in the U.S. that would have to be addressed prior to
changing the approach?
are the research needs associated with a transition?
is the effect of a Safe Systems approach on freight transit and economic
role does mass public transit play in a Safe Systems approach?
This research will result in a
report that provides an overview of available U.S. and international guidelines
to implement Safe Systems well as a description of how these can be currently
utilized in the project development and delivery process at DOTs and other
transportation agencies. As important,
gaps for additional tools will be identified and future research suggested.
North Carolina (UNC) Highway Safety Research Center - Safe Systems Synthesis:
An International Scan for Domestic Application (June 2018) conducted a
literature and policy scan of international practices associated with Safe
Systems. UNC also has an ongoing project – Defining Safe Systems: A Review of
the state-of-the-Practice and Leadership Summit. This project will develop a single,
working definition of the “safe systems” concept. A second activity is to host
a safe systems summit. The proposed research will build off these earlier
minimum, implementation of this study will require:
transportation departments will need broad recommendations on next steps
including future research and data needs;
materials and widespread publication of results for transportation
pathway projections based on potential investment;
time-based goals and performance measures for successful implementation (% of
fatality reduction, % of infrastructure updated, etc)
|Sponsoring Committee:||ANB10, Transportation Safety Management
|Research Period:||12 - 24 months|
|RNS Developer:||Dan Magri, Chad Winchester, Marie Walsh, Adriane McRae, Jessica DeVille|
|Source Info:||Dan Magri, Deputy Assistant Secretary, Office of Planning, LA DOTD|
Chad Winchester, Project Development Division Chief, LA DOTD
Marie Walsh, Louisiana LTAP Director
Adriane McRae, Highway Safety Administrator, LA DOTD
Jessica DeVille, Highway Safety Engineer, LA DOTD
|Index Terms:||Highway safety, Highway design, Highway planning, Europe, Safety management, |
Planning and Forecasting
Safety and Human Factors