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CHAPTER 4
Review of Pedestrian Signal Warrant
This chapter summarizes the research team's review and traffic signal. A secondary factor is walking speed, which is
critique of the existing MUTCD pedestrian traffic signal war- used to adjust pedestrian volumes.
rant. Details on reviews conducted on the pedestrian signal Despite the wide range of factors included in the current
warrant are included in the following appendixes: pedestrian signal warrant, other factors could be considered.
For example, a correlation between acceptable gap criteria and
· Appendix G summarizes international signal warranting factors such as pedestrian age, pedestrian vision (and walking)
practices. abilities, vehicle speed, and roadway cross section is reasonable.
· Appendix H summarizes the basis for and use of the Also, the warrant does not mention safety considerations. Par-
MUTCD pedestrian signal warrant. ticularly critical to this project, there is no consideration of
· A workshop was held to explore the use of engineering judg- pedestrian generators, such as transit stops, within the war-
ment in evaluating intersections to determine if a signal ranting criteria. There are also no allowances for pedestrian
should be considered. The details of the workshop efforts are volumes that could result from the installation of pedestrian-
documented in Appendix I. friendly treatments. Pedestrian delay is the measure used in the
HCM (23) to determine the level of service for pedestrians.
Delay is not directly considered in the signal warrant; however,
The recommendations for changes to the pedestrian signal
it relates to other variables such as pedestrian volume and gaps.
warrant submitted to the National Committee on Uniform
Other attributes of the warrant could be a reference to
Traffic Control Devices in June 2005 and January 2006 are in
alternative means of traffic control and how to determine the
Appendix B. The development of those recommendations,
size of the adequate gap length. The guidance section of the
along with the pedestrian treatment guidelines (which use the
MUTCD could be expanded to note that if a signal is not war-
signal warrant criteria as part of the guidelines) is discussed
ranted, then less restrictive controls may be appropriate, for
in Appendix O. A summary of the critique of the MUTCD
example, in-roadway warning lights. Information on how to
pedestrian signal warrant follows.
calculate critical gaps could provide the user with the pre-
ferred method for determining the value. The Highway
Capacity Manual has a method to calculate critical gap for a
Review of Current Pedestrian
single pedestrian or a group critical gap in Chapter 18 and
Signal Warrant
could be referenced (23).
The current MUTCD pedestrian signal warrant (War- The following summarizes the key factors introduced
rant 4) has many factors to be considered when evaluating above. Additional details are provided in Appendix H.
whether or not a signal is warranted. For this TCRP/NCHRP
project, these factors were split into three levels: primary
Primary and Secondary Factors
factors, secondary factors, and not related to current
research study. These levels reflect the type of requirement Primary and secondary factors include the following:
as indicated in the language of the MUTCD and the rele-
vance to the issue being studied. Primary factors must be · Vehicular Gap. The gap criterion was introduced in 1988.
considered and include available vehicular gaps (based on The criterion was derived from ITE's school crossing
critical gap), pedestrian volume, and distance to the nearest guidelines (dating back to 1962). The guidelines were based
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on an old but common traffic signal timing scheme of fixed assumes a high number of vehicles on the major road;
60-s cycles. It is very difficult to maintain 60-s cycle lengths however, it does demonstrate a difference between vehicles
because of pedestrian phasing and left-turn phasing. and pedestrians.
· Pedestrian Volume. The current pedestrian volumes are · Distance to Nearest Traffic Signal. The current warrant
higher than most of the previous research recommenda- includes a provision that a signal shall not be considered at
tions, which were developed based on different factors. locations within 300 ft (91 m) of another signal. This is
Comparing the pedestrian volumes included in Warrant 4 believed to be based on the distance a pedestrian will walk
with the vehicular volumes in other warrants reveals some in order to cross the major street. The researchers did not
interesting trends. Warrant 2 considers minor road traffic identify data that support this distance or other distances
volume for 4 hours, while Warrant 3 considers minor road of how far beyond the desired path a pedestrian would be
traffic volume for the peak hour. Warrant 4, which uses willing to walk. The U.S. DOT's 1995 Nationwide Personal
pedestrian values, also includes peak hour and 4-hour cri- Transportation Survey did find that most pedestrian trips
teria. A difference is that only one "minor approach" value (73 percent) are 0.5 mi (0.8 km) or less (3). With most trips
is provided in Warrant 4 rather than the sliding scale pres- being about 2,600 ft (792 m), pedestrians might not be
ent in Warrants 2 and 3. In other words, as the major street willing to increase their trip length by more than 10 per-
volume increases in Warrants 2 and 3, the needed minor cent in order to walk to a different crossing location. As
street volume to warrant a signal decreases. For the pedes- part of the on-street pedestrian surveys documented in
trian warrant, a single "minor approach" value is provided. Appendix K, those interviewed were asked "if this crossing
A second difference is that the vehicle warrants include a was not here, would you walk to the next intersection
reduction factor for population and major roadway speed (point to intersection of interest)?" For three of the sites, only
while the pedestrian warrant does not. Another difference about 25 percent of the respondents would walk to a sig-
is the minimum number of vehicles or pedestrians needed nalized intersection at 550, 950, or 1,000 ft (168, 290, or
to warrant a signal. A comparison of the lower threshold 305 m). For the site with a signalized intersection about
volumes is shown in Table 10. For example, an intersection 200 ft (61 m) from the crossing, about 50 percent of those
with only 100 vehicles for the peak hour would warrant interviewed would walk to that crossing. The remaining
a signal before a midblock location with 143 pedestrians site where this question was appropriate did not follow
per hour. When the 70 percent factor is used, the differ- similar findings. A much higher percentage indicated that
ence becomes even more pronounced. An intersection they would be willing to walk to another crossing. Over
could warrant a signal with only 75 vehicles while 143 65 percent of the respondents indicated that they would walk
pedestrians would still be required. This comparison 600 ft (183 m) to cross at a signalized crossing. The greater
Table 10. Comparison of vehicle and pedestrian threshold values.
Lower Threshold Volume
(Pedestrian or Vehicle on Highest Volume
Number of
Minor Road Approach)
Lanes on
Condition Peak Hour Four Hour
Minor Road
Warrant 3 b Warrant 4 c Warrant 2 d Warrant 4 e
Approach
Vehicular Pedestrian Vehicular Pedestrian
(vph) (ped/h) (vph) (ped/h)
2 or more 150 115
Warrant 143 75
1 100 80
2 or more 100 80
70% Factor a 143 75
1 75 60
a
For communities less than 10,000 population or above 40 mph (64 km/h) on major street.
Only applies to Warrants 2 and 3.
b
The minimum minor road volume occurs when the major street volume is approximately
1,450 veh/h or at 1,050 veh/h when the community is less than 10,000 or the speed on the
major road exceeds 40 mph (64 km/h).
c
Warrant 4 requires 190 ped/h crossing the major road in the peak hour. To compare with
Warrant 3, this value was adjusted to a highest approach value by assuming a 75/25
directional distribution split.
d
The minimum minor road volume occurs when the major street volume is approximately
1,050 veh/h or more or at 750 veh/h when the community is less than 10,000 or the speed on
the major road exceeds 40 mph (64 km/h).
e
Warrant 4 requires 100 ped/h crossing the major road during 4 h. To compare with Warrant
2, this value was adjusted to a highest approach value by assuming a 75/25 directional
distribution split.
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number of individuals willing to walk such a distance was handled in the signal warranting criteria (55). The recom-
influenced by the number of lanes at the site (six lanes), mendations include counting pedestrians on the minor
speed and volume of traffic (high), and existing treatment approaches as vehicles and bicycles are counted now, which
(marked crosswalk only). Several of the respondents would change the vehicular-based warrants to all-mode,
selected "yes" to the question and then commented that intersection-based warrants and would allow the pedes-
they walk to the nearby crossing "most of the time" or trian warrant to focus on just the midblock crossing, which
"sometimes" depending on the weather or other factors. would make the warrant more straightforward. The largest
· Reduction Criteria Based on Walking Speeds. In the current issue to be considered is how to count pedestrians versus
warrant, the only reduction factor is based on walking speed, vehicles. The pedestrians are exposed to inclement weather
and it only affects the pedestrian volume criterion. This reduc- conditions, have slower acceleration and speed rates result-
tion factor was introduced in order to accommodate older ing in longer crossing times, and are at considerably more
pedestrians and persons with disabilities. Specifically, if the risk than occupants of vehicles, especially as the major
average walking speed is less than 4 ft/s (1.2 m/s), then a street speeds increase. Therefore, developing an equiva-
reduction of the pedestrian volume of up to 50 percent can be lency factor for pedestrians at intersections seems reason-
implemented. Chapter 6 and Appendix M include recom- able. Critical gaps for vehicles and pedestrians are provided
mendations on walking speeds based on the research con- in the Highway Capacity Manual and the AASHTO Green
ducted as part of this TCRP/NCHRP study. Book (23, 56). Table 11 lists the critical gaps to cross a sam-
ple roadway. A pedestrian requires more time to cross an
intersection than does a vehicle. To cross a two-lane road-
Potential Factors
way, a pedestrian needs 39 percent more time (factor of
Potential factors include the following: 1.4) than does a vehicle. At a four-lane street, a pedestrian
needs twice as much time (or a factor of 2.0) than does a
· Pedestrian Generators (Transit Stops). The closeness of a vehicle. Canada's pedestrian signal procedure includes
pedestrian generator is not considered within the current equivalent adult units with children and those with dis-
pedestrian signal warrant. abilities counting as 2.0 adults and seniors counting as 1.5
· School Warrant. The school signal warrant has a unique adults. The concept of counting all road users on the minor
feature that may lend itself to the handling of all pedestrian street approach is not novel to the MUTCD. The current
crossing treatments. In the school warrant, the main con- MUTCD multi-way Stop warrant has a criterion that
sideration is the ratio of the number of adequate gaps to includes the summation of vehicles, bicycles, and pedestri-
the number of minutes the crossing is being used. This ans on the minor street approach.
ratio could be used to set thresholds for various crossing · Vehicle Speed. Most of the current vehicular-based traffic
treatments. signal warrants include a reduction factor based on the
· Crash Experience. As indicated in Appendix G, other speed of the vehicles on the major street. The pedestrian
countries use crash experience to justify the installation of signal warrant also included the same reduction factor
a traffic signal. The MUTCD includes a crash experience until the 1988 revision.
warrant, but it is focused on vehicular crashes. Including a · Pedestrian Delay. The HCM includes a procedure to esti-
factor in the warranting criteria that considers safety in mate pedestrian delay for an unsignalized intersection. The
terms of pedestrian-related crashes, especially because of average delay of pedestrians at an unsignalized intersection
the vulnerability associated with pedestrian crashes, may crossing depends on the critical gap, the vehicular flow rate
be reasonable. of the subject crossing, and the mean vehicle headway. The
· Counting Pedestrians on the Minor Approach with HCM Exhibit 18-13 (reproduced as Table 12) is then used to
Vehicular and Bicycle Volumes. Other research has rec- determine the LOS of the crossing. A signal warrant could be
ommended more global changes to the way pedestrians are developed based on a function of the pedestrian delay.
Table 11. Critical gaps for vehicles and pedestrians at an
unsignalized intersection.
Critical Gaps
Through Lanes
Vehicle (s) Pedestrians (s)
2 6.5 9.0
4 7.5 15.0
HCM Equation 18-17,
Green Book Exhibit 9-57, assume 12-ft (4-m) lanes, 4
Source
assume passenger car ft/s (1.2 m/s) walking speed,
and 3-s start up
