TECHBRIEF Impacts of LED Brightness, 

Flash Pattern, and Location 

for Illuminated Pedestrian 

Traffic Control Device

FHWA Publication No.: FHWA-HRT-15-042

FHWA Contact: Ann Do, HRDS-30, (202) 493-3319, 

ann.do@dot.gov

Introduction

Illuminated traffic control devices, such as rectangular 

rapid-flashing beacons (RRFB), have been shown to 

increase the number of drivers yielding to crossing 

pedestrians. Evaluations of field installations of these 

devices have been conducted in several locations, 

including Florida, Texas, Oregon, Michigan, Arizona, 

Wisconsin, and Calgary, AB. (See references 1 through 10.) 

Before-after studies have shown a large increase in 

driver yielding between the before period (range of 1 to 

83 percent) and the after period (range of 38 to 

98 percent). While driver yielding has always increased 

after the RRFB installation, there are still examples of 

low yielding in some locations. Studies have shown a 

wide range in driver yielding to the RRFB, with values 

extending from a low of 22 percent to a high of 98 percent. 

There is growing interest in adding the RRFB to the 

Manual on Uniform Traffic Control Devices (MUTCD).(11)

The Signals Technical Committee of the National 

Committee on Uniform Traffic Control Devices, which 

assists in developing language for chapter 4 of the 

MUTCD, is interested in research to support proposed 

language for inclusion of RRFBs in the manual. To achieve 

the uniformity desired in the MUTCD and provide 

guidance that results in the best driver yielding behavior, 

several details require research. These details include 

beacon size, shape, color, placement location, brightness, 

and flash pattern. There is some concern that the brightness of flashes at or contained within signs at night may 

Research, Development, and 

Technology

Turner-Fairbank Highway 

Research Center

6300 Georgetown Pike

McLean, VA 22101-2296

www.fhwa.dot.gov/research
2

make it difficult for drivers to detect and 

observe the movements of pedestrians at 

the crossing. To prevent devices from being 

set at brightness levels that produce disability or discomfort glare, the profession 

needs to quantify the effect of illuminated 

traffic control devices on a driver’s ability 

to detect pedestrians in and around the 

crosswalk.

This TechBrief describes the methodology and results from a closed-course 

study sponsored by the Federal Highway 

Administration (FHWA) that addressed 

brightness, flash patterns, and location of 

light-emitting diodes (LED). It examined 

driver detection of cutout pedestrian photographs in the presence of LEDs of various 

brightness levels and flash patterns, which 

are placed in different locations within the 

sign assembly.(12)

Study Approach

Study Method

The study enlisted 98 licensed drivers 

(aged 19 to 85). They were placed in a 

vehicle 200 ft from a crosswalk. Their basic 

task was to identify as quickly as possible which direction a pedestrian cutout 

photograph appeared to be walking. Lifesized photo cutouts of adult and child size 

pedestrians were used (figure 1). These 

cutout photographs were placed in one 

of three positions within the crosswalk. 

To control when the drivers could see 

the scene, the participants wore special 

glasses that blocked their view with an 

opaque film. With the press of a button, 

the film became transparent, and the 

subject could begin searching for the 

pedestrian. The amount of time needed 

to correctly identify the direction of travel 

of the pedestrian was the measure of 

performance. Following the driver’s 

identification of the pedestrian’s direction 

and the darkening of the glasses, the 

researcher asked the participant to rate 

the brightness of the sign as comfortable, 

irritating, or unbearable.

The pedestrian detection study was 

conducted on a closed course (a former 

taxiway at the Texas A&M University 

Figure 1. Researcher removing short cutout pedestrian after placing tall cutout pedestrian.

Source: Texas A&M Transportation Institute.
3

Riverside campus) where edge line, center 

line, and transverse crosswalk markings 

were added to give the site a more urban 

feel and to simulate two vehicles approaching a pedestrian crossing on a multilane 

divided road. Each lane was approximately 

12 ft wide, and the width of the paved 

surface was about 40 ft. The study was 

designed so that data would be collected 

from two participants simultaneously 

seated in separate vehicles (i.e., participants could not hear each other’s 

responses). Street lighting—in the form 

of two work zone light towers—was 

present at the site for the nighttime 

testing, and drivers were instructed to 

keep the low-beam headlamps on during 

nighttime testing. Testing occurred during 

both daytime and nighttime.

The sign assemblies consisted of a pedestrian crossing sign with LEDs within the 

sign face and LEDs in rectangular beacons 

above and below the sign. The height to 

the middle of the sign was approximately 

9.5 ft, with the height to the bottom edge 

of the bottom beacon at 7 ft and the bottom 

edge of the top beacon at 11.6 ft. 

Features Studied

The study focused on the following three 

features of illuminated pedestrian traffic 

control devices:

• Location of LEDs in the sign assembly 

(above sign, below sign, or embedded 

within the sign border).

• LED brightness (intensity) levels.

• Flash patterns.

Table 1 lists the variable combinations 

studied. The total number of all possible 

combinations was too large to evaluate for 

any one driver. Therefore, each driver was 

presented with a sample of 105 combinations in the 1-h testing period. The order 

of the combinations was randomized and 

balanced across driver groups to avoid 

biasing results due to presentation order, 

fatigue, or practice.

Group Variable combinations

Participant 

characteristics

• Gender (2): male or female.

• Age (2): young (less than 55 yr) or old (55 yr or older)—used during 

participant recruitment; however, actual age was used in analysis.

Site characteristics

• Time of day (2): day (natural light) or night (with street light at 25 to 27 lux).

• Lane (2): left lane or right lane.

• Viewing position (1): 200 ft upstream from assemblies.

Study assemblies 

characteristics

• LED location (4): LEDs in rectangular beacon below sign active, LEDs in 

rectangular beacon above sign active, LEDs within sign active, or no LEDs active 

(i.e., LEDs are not illuminated).

• Flash patterns (7): 3 for rectangular beacons, 3 for LEDs within, no flash pattern 

(i.e., LEDs are not illuminated), see figure 4 for illustrations of flash patterns.

• Target intensity (a measure of brightness) (4): 0, 600, 1,400, and 2,200 cd.

Cutout pedestrian 

characteristics

• Pedestrian position (4): none, right side, center, or left side.

• Pedestrian height, when present (2): tall (5.75 ft) or short (4.5 ft).

• Pedestrian direction, when present (2): left or right.

Table 1. Variable combinations studied.

cd = Candelas.

LED = Light-emitting diode.
4

Location of LEDs

In accordance with the Interim Approval 

(IA-11), the RRFB light bars are to be located 

below the sign face.(13) However, placing 

the bars above the sign may offer some 

advantages. The devices tested are shown 

in figure 2 and figure 3.

Brightness of LEDs 

The brightness characteristics of the LEDs 

may affect the detection of pedestrians, 

particularly at night. In this study, researchers measured brightness using intensity, 

which is a method for quantifying brightness defined by Society of Automotive 

Engineers (SAE) Standard J595.(14) To quantify the brightness of the pulsing lights, 

a researcher measured the 95th-percentile 

peak intensity. The researchers took 

the measurements at a vertical angle 

of 0 degrees and a horizontal angle of 

0 degrees. Three levels of intensity were 

selected for the study. The minimum

value was 600 candelas (cd), which is the 

minimum value for an RRFB within the 

interim approval. The maximum brightness value of 2,200 cd reflected the value 

researchers could consistently obtain 

during study development for the range of 

equipment available. A midpoint value of 

1,400 cd was also used.

Flash Patterns

Six flash patterns were tested, and each 

was compared with a control condition of no illumination (see figure 4). The 

2-5 flash pattern was selected based on 

FHWA official interpretation 4(09)-21 (I).(15)

The other flash patterns reflected either 

patterns available within the controllers 

Figure 2. RRFB bar locations tested. (Note that only one 

bar unit was activated at a time.) Figure 3. Embedded LED sign tested.

Source: Texas A&M Transportation Institute. Source: Texas A&M Transportation Institute.
5

Figure 4. Flash patterns tested.

Source: Texas A&M Transportation Institute.

Flash patternaPulse rateb (number of pulses/cycle duration) On ratioc (percent)

Wig-wag 2.00 100

2-5 8.75 69

2x125 ms 2.50 31

5 pulses 6.25 38

1x100 ms 1.00 10

Table 2. Characteristics of flash patterns.

a

See figure 4 for illustrations of flash patterns.

b

Pulse rate is determined as the number of pulses divided by the cycle duration. For example, the 2-5 pattern 

has seven pulses within the 0.8-s cycle for a pulse rate of 8.75, while the rapid-flashing LEDs within a sign 

have five pulses within the 0.8-s cycle for a pulse rate of 6.25. 

c

On-ratio is the percent of the 25 ms increments within a cycle in which the LEDs within the beacon or sign are 

illuminated. For example, in the wig-wag pattern, there are no dark periods; thus, it has an on-ratio of 100 percent.
6

donated for the study or portions of an 

available pattern determined to be viable 

alternatives for comparison. Because the 

amount of time the LEDs are on within 

each cycle may influence a driver’s ability to detect a pedestrian, researchers also 

considered the percent of cycle time when 

the LEDs were illuminated. (See table 2 for 

calculated values.)

RESULTS

Pedestrian Detection Time

Table 3 provides calculated median detection times to aid in illustrating the effects of 

a variable. Note that these values are based 

on several assumptions, such as age of the 

participant or beacon intensity, as listed in 

the table. They do not represent all possible 

combinations of statistical comparisons 

and are provided as examples.

On average, drivers took longer to detect 

the pedestrian cutout photographs in the 

nighttime (1,404 ms) than in the daytime 

(1,137 ms), with a difference of 267 ms. 

For this study, brightness intensity did not 

have a significant impact on driver detection time for daytime conditions but was 

significant for nighttime conditions. 

Nighttime detection time increased by 

8.5 percent at 2,200 cd (the maximum 

used in the study), compared with when 

the LEDs were off. The brighter the LEDs, 

the longer it took for the participants to 

determine which direction the pedestrian 

was facing. 

Only two flash patterns produced significantly longer detection times when 

compared with the control condition 

of no LED illumination: the 2-5 pattern 

(during the day and at night) and the 

wig-wag pattern (only at night). These 

detection times were produced when 

the light bar was both above the sign 

face and below the sign face. Compared 

with the control condition (i.e., LEDs are 

not illuminated), the 2-5 pattern caused 

an increase in median detection time of 

5.2 percent during day and 6.0 percent 

at night. The wig-wag pattern caused an 

increase of 13.7 percent in median nighttime detection time. For example, nighttime median detection was significantly 

faster when LEDs were dark (1,730 ms) 

compared with flashing the wig-wag 

pattern at 2,200 cd (2,108 ms), with a 

difference of 378 ms. This 22-percent 

increase in median detection time reflects 

an additional 13.7 percent because of the 

wig-wag pattern and 8.5 percent because of 

the intensity of 2,200 cd (i.e., 1.22 is approximately equal to 1.137 times 1.085). 

LED location had a significant impact at 

night but not during the day. At night, 

detection was fastest when the LEDs were 

above the sign face, after controlling for 

other factors such as intensity. Compared 

with the LED location above the sign, the 

median detection time increased 

6.0 percent when the LEDs were within 

the sign, and it increased an additional 

6.0 percent when the LEDs were below the 

sign for a total of a 12.3-percent increase 

when the below location was compared 

with the above location. As an example, 

to detect a short pedestrian under the 

assembly with LEDs at 2,200 cd and the 

wig-wag flash pattern, the expected (i.e., by 

statistical analysis) nighttime median 

detection times for the three LED positions are as follows: 1,877 ms for 

LEDs above, 1,989 ms for LEDs within, 
7

and 2,108 ms for LEDs below. The difference between below and above is 231 ms.

Some of the other variables tested showed 

small differences in detection time 

(< 5 percent) but statistically significant 

differences between conditions. These 

variables included pedestrian height, 

with shorter pedestrians detected slightly 

more slowly; pedestrian position, with 

pedestrians in the center of the crosswalk 

detected slightly more quickly than those 

on the sides; and age, with average daytime 

detection time being slower for the older 

participants than the younger ones.

Variable Combinations Daytime (ms) Nighttime (ms)

Flash pattern

None 925a

1,361a

2-5 989a,b 1,519a,b

Wig-wag 961a1,629a,b

1x100 ms 982a1,387a

2x125 ms 940a1,422a

5 pulses 981a1,409a

LED location

Below 989c

1,519c

Within 978c1,433c,d

Above 982c1,352c,d

Brightness level 

(cd)

0 925e,f 1,361e,g

600 980e,f 1,475e,g

1,400 989e,f 1,519e,g

2,200 998e,f 1,564e,g

Pedestrian position Under assembly 989h

1,519h

Center crosswalk 934h,i 1,270h,i

Table 3. Examples of median detection times for a given set of assumptions.

a

Median detection times represent the following conditions: beacon intensity of 1,400 cd, LED located below 

the assembly, short pedestrian under the assembly, and 50-yr-old participant.

b

Statistically different from “None.”

c

Median detection times represent the following conditions: beacon intensity of 1,400 cd, 2-5 flash pattern, 

short pedestrian under the assembly, and 50-yr-old participant.

d

Statistically different from “Below.”

e

Median detection times represent the following conditions: LED location below, 2-5 flash pattern, short 

pedestrian under the assembly, and 50-yr-old participant.

f

An exponential increase of 0.11 percent in median detection time for an additional 100 cd of intensity was 

identified; however, it was found not to be statistically significant.

g

An exponential increase in median detection time across all brightness levels was found statistically significant. This effect corresponds to an increase of 0.37 percent in median detection time for an additional 100 cd 

of intensity.

h

Median detection times represent the following conditions: beacon intensity of 1,400 cd, LED located below 

the assembly, 2-5 flash pattern, short pedestrian, and 50-yr-old participant.

i

Statistically different from “Under Assembly.”

Bold numbers are statistically significant.

LED = Light-emitting diode.
8

Discomfort Glare

Participants rated their discomfort with 

the glare from the assemblies as comfortable, irritating, or unbearable. As expected, 

there were clear differences in the ratings 

between daytime and nighttime. Table 4 

provides the distribution for comfort levels 

for nighttime conditions to aid in discussions. Note that these values represent the 

assumption discussed in the table and not 

all possible combinations. 

Not surprisingly, LED intensity was correlated with nighttime discomfort level; as 

brightness levels increased, the percent 

of drivers saying unbearable increased 

(statistically significant). Similarly, there 

is convincing evidence of lower discomfort levels for the short pedestrian compared with the tall pedestrian. 

For nighttime only, LED location had a 

significant impact on discomfort levels. 

This analysis found evidence of higher 

Variable Combinations Comfortable 

(percent)

Irritating 

(percent)

Unbearable 

(percent)

Flash pattern

None 98a

2a0a

2-5 48a,b 45a,b 7a,b

Wig-wag 56a,b 39a,b 5a,b

1x100 ms 77a,b 21a,b 2a,b

2x125 ms 57a,b 38a,b 5a,b

5 pulses 60a,b 35a,b 5a,b

LED location

Below 48c

45c7c

Within 47c45c8c

Above 63c,d 33c,d 4c,d

Brightness level 

(cd)

0 98e 2e

0e

600 68e,f 29e,f 3e,f

1,400 48e,f 45e,f 7e,f

2,200 29e,f 56e,f 15e,f

Pedestrian position Under assembly 48g

45g7g

Center crosswalk 63g,h 33g,h 4g,h

Table 4. Examples of nighttime discomfort glare distributions for a given set of assumptions.

a

Discomfort glare proportions represent the following conditions: beacon intensity of 1,400 cd, LEDs below 

the assembly, short pedestrian under the assembly, and 50-yr-old participant.

b

All flash patterns produced discomfort glare levels statistically different from no flash pattern at all.

c

Discomfort glare proportions represent the following conditions: beacon intensity of 1,400 cd, 2-5 flash pattern, short pedestrian under the assembly, and 50-yr-old participant.

d

Statistically different from “Below.”

e

Discomfort glare proportions represent the following conditions: LED location below, 2-5 flash pattern, short 

pedestrian under the assembly, and 50-yr-old participant.

f

A continuous logistic effect across all brightness levels was found statistically significant, corresponding to a 

9.3-percent increase in the odds of higher discomfort levels per additional 100 cd of intensity.

g

Median detection times represent the following conditions: beacon intensity of 1,400 cd, LED located below 

the assembly, 2-5 flash pattern, short pedestrian, and 50-yr-old participant.

h

Statistically different from “Under Assembly.”

Bold numbers are statistically significant.

LED = Light-emitting diode.
9

discomfort levels when the LEDs were 

located below the sign, compared with 

LEDs above the signs, after controlling for 

other factors such as intensity.

For nighttime only, pedestrian position 

had an impact on driver discomfort level. 

Locating the pedestrian near the beacons 

on either side of the crosswalk yielded 

higher discomfort compared with when the 

cutout was located at the center of the 

crosswalk. This effect is probably associated with the proximity to the active LEDs. 

No evidence of higher driver discomfort 

was found when the pedestrian cutout was 

placed on the right side compared with 

when it was placed on the left side. 

For nighttime only, there is convincing 

evidence that the flash pattern has an 

impact on discomfort levels. Not surprisingly, the analysis found a significant 

increase in discomfort ratings associated 

with any flash pattern when compared 

with no flash pattern (i.e., LEDs are not 

illuminated). 

Discussion

The flash pattern, along with the brightness of LEDs, whether used within a light 

bar above or below the sign or embedded 

in a sign, can help draw drivers’ attention 

to a device and the area around the device. 

Field studies have shown improvements 

in drivers’ yielding to pedestrians at 

locations where these devices have been 

deployed. However, characteristics of the 

LEDs, such as brightness, location, or flash 

pattern, can also make it more difficult for 

drivers to see objects at or near a device or 

may result in drivers looking away from a 

device. This study used several measures 

to gain an understanding of how brightness, flash pattern, and location of LEDs 

affect drivers’ ability to detect a pedestrian 

cutout within a crosswalk equipped with 

an RRFB. These measures included the 

time to correctly identify pedestrian walking direction and the participant’s rating 

of discomfort glare. 

The brighter the LEDs, the longer it took 

for the participants to determine which 

direction the pedestrian was facing. In 

other words, lower brightness is associated 

with reduced disability glare. The brightness intensities of the LEDs used in this 

study was 0 cd (i.e., the LEDs were not 

illuminated), 600 cd, 1,400 cd, and 2,200 cd. 

In another FHWA study, devices installed 

in the field were measured with higher 

brightness intensity (up to 3,000 cd), so 

the brightness levels used in this closedcourse study do not exceed the values 

being used for some on-road RRFB installations.(7) The brightness of LEDs in the 

field appears to be highly variable. Part 

of the reason for the variability could be 

that current requirements only specify a 

minimum intensity. The minimum intensity 

is defined within SAE Standard J595; the 

minimum is 600 cd measured at a horizontal angle of 0 and a vertical angle of 0 for 

Class I yellow peak luminous intensity.(14)

The findings for pedestrian position and 

LED location indicate that the distance 

between the pedestrian and the light 

source affect the ability to quickly detect 

the pedestrian. When the pedestrians 

were located at the edge of the crosswalk 
10

(i.e., next to the assembly) and when the 

LEDs were located below the sign (i.e., 

closer to the pedestrian), detection time 

was longer. These findings support the 

idea of placing the LEDs above rather than 

below the sign. Another area of potential 

investigation is locating the LEDs over the 

roadway rather than on the roadside. Such 

a study would need to consider whether 

changes are needed in the LED designs 

(e.g., aiming the LEDs to flash downward 

toward the drivers).

The shorter-height pedestrian required 

more time to detect, which is an expected 

finding. Child-sized pedestrians are a 

known concern for pedestrian detection in 

crosswalks. 

Some of the flash patterns used with 

the devices were associated with longer 

pedestrian detection times. Of the six flash 

patterns tested, only two flash patterns—

the 2-5 and the wig-wag—were associated 

with statistically significantly longer 

detection times when compared with the 

control no illumination condition. Both of 

these patterns have longer on times (the 

2-5 is on 69 percent of the cycle, and the 

wig-wag is on 100 percent of the cycle) 

compared with the other patterns (range of 

10 to 38 percent on time). The LEDs being 

constantly “on” may cause the participants 

to look away from them. In addition, the 

lack of sufficient dark periods between the 

flashes may be limiting the participant’s 

ability to adequately search for the 

pedestrian. A better flash pattern than the 

current 2-5 pattern should retain multiple 

pulses (because survey results found that 

participants felt patterns with multiple 

pulses are associated with greater urgency), 

more or longer dark periods (because this 

study found longer detection time for patterns with fewer dark periods), and a maximum intensity that limits discomfort when 

attempting to detect objects while still commanding driver attention (i.e., resulting in 

high driver yielding).(16) 

References 

1. Shurbutt, J., and Van Houten, R. 

(2010), Effects of Yellow Rectangular 

Rapid-Flashing Beacons on Yielding 

at Multilane Uncontrolled Crosswalks, 

FHWA-HRT-10-043, FHWA, Washington, 

DC.

2. Pécheux, K., Bauer, J., and McLeod, P. 

(2009), Pedestrian Safety Engineering 

and ITS-Based Countermeasures 

Program for Reducing Pedestrian 

Fatalities, Injury Conflicts, and Other 

Surrogate Measures Final System 

Impact Report, FHWA, U.S. Department 

of Transportation, Washington, DC.

3. Hunter, W.W., Srinivasan, R., and 

Martell, C.A. (2009), Evaluation of the 

Rectangular Rapid Flash Beacon at a 

Pinellas Trail Crossing in St. Petersburg, 

Florida, Florida Department of 

Transportation, Tallahassee, FL.

4. Brewer, M.A., Fitzpatrick, K., Larson, 

G.W., and Minter, H. (2011), Beforeand-After Study of the Effectiveness of 

Rectangular Rapid-Flashing Beacons 

Used with School Sign in Garland, 

Texas, Technical Memorandum to City 

of Garland Department of Transportation, TTI, College Station, TX.
11

5. Fitzpatrick, K. et al. (2014), Characteristics 

of Texas Pedestrian Crashes and Evaluation of Driver Yielding at Pedestrian 

Treatments, FHWA/TX-14/0-6702-1.

6. Fitzpatrick, K., Brewer, M., and Avelar, 

R., “Driver Yielding to Traffic Control 

Signals, Pedestrian Hybrid Beacons, and 

Rectangular Rapid Flashing Beacons in 

Texas,” Transportation Research Record: 

Journal of the Transportation Research 

Board, 2463.

7. Fitzpatrick, K. et al. (2014), Investigating 

Improvements to Pedestrian Crossings 

With an Emphasis on the Rectangular 

Rapid-Flashing Beacon, Draft Final 

Report HRT-15-043, FHWA, McLean, VA.

8. Ross, J., Serpico, D., and Lewis, R. 

(2011), Assessment of Driver Yielding 

Rates Pre- and Post-RRFB Installation, 

Bend, Oregon, Oregon Department of 

Transportation, Salem, OR.

9. Bennett, M.K., Manal, H., Van Houten, 

R. (2014), “A Comparison of Gateway 

In-Street Sign Configuration to Other 

Driver Prompts to Increase Yielding to 

Pedestrians at Crosswalks,” Journal of 

Applied Behavior Analysis, 47(1), Spring 

2014.

10. Domarad, J., Grisak, P., and Bolger, J. 

(2013), “Improving Crosswalk Safety: 

Rectangular Rapid-Flashing Beacons 

(RRFB) Trial in Calgary,” Canada Institute 

of Transportation Compendium, last 

accessed April 3, 2015, http://www.cite7.

org/conferences/compendium/2013_

Pedestrian_ImprovingCrosswalkSafety.

pdf

11. FHWA (2009), Manual on Uniform Traffic 

Control Devices, last accessed January 5, 

2011, http://mutcd.fhwa.dot.gov/kno_

2009.htm.

12. Fitzpatrick, K. Avelar, R., and Robertson, 

J. (2014), Rapid-Flash Yellow LEDs 

Impact on Detecting Pedestrians in a 

Closed-Course Setting, Draft Technical 

Memorandum to FHWA.

13. Furst, A. (2008), MUTCD—Interim 

Approval for Optional Use of Rectangular Rapid Flashing Beacons (IA-11), 

Memorandum, FHWA, U.S. Department 

of Transportation, July 16, Washington, 

DC.

14. SAE International (2005), Surface Vehicle 

Recommended Practice, SAE Standard 

J595, January.

15. Kehrili, M. (2012), 4(09)-21 (I)—

Clarification of RRFB Flashing Pattern, 

Memorandum, FHWA, U.S. Department 

of Transportation, June 13, Washington, 

DC.

16. Fitzpatrick, K., Robertson, J., and 

Avelar, R. (2015), Survey on Message 

Communicated by Rapid-Flashing 

Yellow LEDs Used With Pedestrian 

Crossing Sign, accepted for presentation at the 2015 TRB Annual Meeting.
12

MAY 2015 FHWA-HRT-15-042

HRDS-30/05-15(WEB)E

Researchers—This study was performed by Principal Investigator Kay Fitzpatrick along with Raul 

Avelar, and James Robertson. For more information about this research, contact Dr. Kay Fitzpatrick, 

Texas A&M Transportation Institute, 2935 Research Parkway, College Station, TX 77845-3135, 

k-fitzpatrick@tamu.edu.

Distribution—This TechBrief is being distributed according to a standard distribution. Direct 

distribution is being made to the Divisions and Resource Center.

Availability—This TechBrief may be obtained from the FHWA Product Distribution Center by e-mail to 

report.center@dot.gov, fax to (814) 239-2156, phone to (814) 239-1160, or online at http://www.fhwa.dot.

gov/research.

Key Words—Rectangular rapid-flashing beacon, flash patterns, LED brightness, pedestrian crossing, 

driver yielding to pedestrians, embedded LED signs.

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