Chapter 1 Introduction
THE PROBLEM
One of the primary causes of crashes at signalized
intersections involves a vehicle entering an intersection
when the red signal is displayed. This type of collision
occurs frequently. According to preliminary estimates
by the Federal Highway Administration (FHWA) for
2001, the most recent year for which statistics are
available, there were nearly 218,000 red-light running
crashes at intersections (1). These crashes resulted in as
many as 181,000 injuries and 880 fatalities, and an
economic loss estimated at $14 billion per year. Clearly,
red-light running, which is reported to be on the rise as
with other aggressive driving behaviors such as
speeding, tailgating and not stopping or even slowing at
stop-controlled intersections, has become a national
safety problem.
Red-light running is also a complex problem. There is
no simple or single reason to explain why drivers run
red lights. There is a tendency to cite driver error-either intentional or unintentional disregard of the traffic signal. As will be presented in the report, redlight runners are more likely to be younger than 30-years old, have a record of moving violations, are driving without a valid license and/or have consumed alcohol. There are elements of driver psychology and
sociology behind the violations and any driver may be
susceptible to committing a violation. There is also
evidence that drivers may be induced into running red
lights because of improper signal design or operation.
These elements make red-light running difficult to
predict and a difficult problem to solve.
ALTERNATIVE SOLUTIONS
As with many safety problems, the solution to the redlight
running problem requires a combination of
countermeasures involving the three "E"s
stakeholders-education, enforcement and engineering.
Educational solutions start with instructing newly
licensed drivers on the traffic laws and the rules
regarding yellow- and red-signal displays. They
continue with public information campaigns, such as
television and radio public service announcements, that
alert the public of the red-light running problem and its
crash severity consequences.
Since every crash involving a red-light runner involves
a traffic violation, it is only natural that traffic law
enforcement be one of the countermeasures to consider.
Enforcement includes both selective police patrols, and
more recently in some jurisdictions, automatedenforcement
cameras. Traditionally, police enforcement
involves targeted enforcement of red-light violations at
intersections with a high number of violations and/or
crashes. However, this type of enforcement is labor
intensive and therefore costly, and it can be hazardous,
providing only short-lived effectiveness.
In some jurisdictions across the country, automatedenforcement
systems, which use vehicle sensors and
cameras to automatically identify a red-light runner and
subsequently issue a citation, are being used to reduce
these violations. Based on a recent synthesis of
literature related to the safety impacts of automatedenforcement
programs, these systems do reduce the
incidence of red-light violations and can improve intersection safety, not only at the intersections where
they are installed but at others within their influence
area (2). While neither thoroughly conclusive nor
consistent for all intersections, these systems tend to
reduce angle crashes (those that most often result from
red-light running violators) to a larger extent than the
increase in rear-end crashes that may be experienced.
Overall intersection safety improvement is realized
because angle crashes are usually more severe than
rear-end crashes, resulting in injury and/or fatality.
Nonetheless, these systems have come under scrutiny
and criticism for a number of reasons related to privacy
and fairness. With regard to the latter, they "catch" all
types of red-light runners, some who violate the signal
intentionally, but others who enter on red
unintentionally. This may be attributed, in part, to
deficiencies related to the design and/or operation of the
intersection.
Numerous reports and anecdotal evidence from around
the United States and the world, suggest that there are a
number of engineering features of intersections that
contribute to red-light running. For example, yellowchange
intervals can be set so low that they trap
motorists into running red lights. At intersections with
limited sight distance to the signals, it can be difficult
for a motorist to see the signals in enough time to avoid
running the red light. Since engineering deficiencies
such as these can contribute to red-light running,
correcting and implementing other engineering
countermeasures minimize the extent of red-light
running and can sometimes obviate the use of automated-enforcement systems.
OBJECTIVE OF REPORT
Often enforcement measures, whether they be selective
police or automated systems, are initiated before
consideration is given to addressing the problem
through engineering solutions. This "toolbox" will
identify what engineering features of an intersection
should be considered to discourage red-light running. It
addresses design and operational features that may need
to be upgraded as necessary. It is intended to provide a
background of the characteristics of the red-light
running problem; identify how various engineering
measures can be implemented to solve this problem; suggest a procedure for selecting the appropriate
engineering measures; and provide guidance on when
automated-enforcement systems may be appropriate.
The report is intended for several types of readers.
Engineers trained in the design and operation of
signalized intersections should already be cognizant of
the engineering measures discussed. Still, they can
benefit from being reminded of good engineering
practice with the provision of a single information
source focused on this topic. Law enforcement officials
should become more sensitized to the various
engineering features that affect red-light running and be
supportive of their implementation prior to taking
aggressive enforcement measures. Other officials who
feel that aggressive enforcement measures, (including
automated systems) should be implemented on a large
scale basis will be made aware that engineering
measures have the potential to reduce red-light running,
which may address the resulting safety problem more adequately and equitably.
REPORT ORGANIZATION
Beyond these introductory remarks, the reader will find in:
- Chapter 2, a discussion of the red-light running
problem-what it is, who the offenders are, the
characteristics of red-light running and the crash
and severity consequences.
- Chapter 3, an identification and discussion of
various engineering measures that can be
implemented to reduce red-light running and
promote a safer intersection. The measures are
described, and if known, their safety effectiveness
is presented, as well as other considerations for
deployment.
- Chapter 4, a systematic program for identifying a
red-light running problem and selecting
appropriate engineering countermeasure(s) to
reduce the occurrence of violations and related
crashes. It also provides guidance on when and
where automated systems may be beneficial.
- Chapter 5, a discussion of what future actions need to be taken to address the issue and provide the best
possible guidance for minimizing red-light running.
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