Highway administrators, engineers, and researchers often face problems for which in-
formation already exists, either in documented form or as undocumented experience and
practice. This information may be fragmented, scattered, and unevaluated. As a conse-
quence, full knowledge of what has been learned about a problem may not be brought to
bear on its solution. Costly research findings may go unused, valuable experience may be
overlooked, and due consideration may not be given to recommended practices for solv-
ing or alleviating the problem.
  There is information on nearly every subject of concern to highway administrators
and engineers. Much of it derives from research or from the work of practitioners faced
with problems in their day-to-day work. To provide a systematic means for assembling
and evaluating such useful information and to make it available to the entire highway
community, the American Association of State Highway and Transportation Officials—
through the mechanism of  the National Cooperative Highway Research Program—
authorized the Transportation Research Board to undertake a continuing study. This
study, NCHRP Project 20-5, “Synthesis of Information Related to Highway Problems,”
searches out and synthesizes useful knowledge from all available sources and prepares
concise, documented reports on specific topics. Reports from this endeavor constitute an
NCHRP report series, Synthesis of Highway Practice.
  The synthesis series reports on current knowledge and practice, in a compact format,
without the detailed directions usually found in handbooks or design manuals. Each re-
port in the series provides a compendium of the best knowledge available on those meas-
ures found to be the most successful in resolving specific problems.

  This synthesis report provides a review of the state of the practice of road safety audit
(RSA) and road safety audit review (RSAR) applications for U.S. states and Canadian
provinces. Transportation safety professionals with these agencies and with local and re-
gional entities, as well as others in both the public and private sectors, may be interested
in this documentation of international, state, and some local agency approaches to the use of
these tools in comprehensive safety programs. This synthesis of the Transportation Research
Board places emphasis on North American applications. However, this document also dis-
cusses international practice as RSAs were first introduced in the United Kingdom more
than 20 years ago, and RSAs have been extensively applied in New Zealand and Austra-
lia since the 1990s. This document promotes the use of RSAs and RSARs. The increased
use of these applications may help reduce roadway crashes and fatalities.  
  For this synthesis report of the Transportation Research Board survey responses were
received from 38 state departments of transportation (DOTs) and 6 Canadian provinces.
The state of the practice was developed based on this 2003 survey, state, and local
agency practices, Federal Highway Administration- and National Highway Institute-
sponsored training for state DOTs, local agency training experiences, international prac-
tices, literature, and personal contacts.   
  A panel of experts in the subject area guided the work of organizing and evaluating
the collected data and reviewed the final synthesis report. A consultant was engaged
to collect and synthesize the information and to write this report. Both the consultant and
the members of the oversight panel are acknowledged on the title page. This synthesis is
an immediately useful document that records the practices that were acceptable within
the limitations of the knowledge available at the time of its preparation. As progress in
research and practice continues, new knowledge will be added to that now at hand.