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The author is SeniorResearch Engineer, TexasTransportation Institute,Texas A&M University,College Station, andchair of the TRBOperational Effects ofGeometrics Committee.

T he number of people who choose to walk or toride a bicycle instead of driving has increased inrecent years, because of the cost of transporta-

tion, the desire for healthier lifestyles, and for otherreasons. Pedestrians and bicyclists, however,encounter serious risks—a large number are killed intraffic accidents every year in the United States.

ProblemMany roadway crossing treatments are available toaddress concerns about the safety of pedestrians (1), butonly a few are appropriate for high-speed conditions orfor wide crossings. In the late 1990s, Richard Nassi,then transportation administrator for the City of Tuc-son, Arizona, developed the High-Intensity ActivatedCrosswalk, or HAWK, pedestrian beacon; the 2009Manual on Uniform Traffic Control Devices (MUTCD)calls the device the pedestrian hybrid beacon (2).

The HAWK is designed to assist in pedestriancrossings, especially at major arterials with minorstreet intersections (3). The HAWK stops vehicles sothat pedestrians can cross the roadway and then per-mits the drivers to proceed as soon as the pedestri-ans have passed. Because signal control on a side

street could encourage unwanted additional trafficthrough the neighborhood, the HAWK was designedwith stop control on the side streets.

At a HAWK crossing, drivers receive multiple cuesfor the possible presence of a pedestrian. The cuesinclude

u A unique beacon configuration—two redlenses over a single yellow lens;

u High-visibility crosswalk markings, in a lad-der style distinct from two transverse white lines;

u A stop bar approximately 50 ft from the cross-walk;

u Solid lane lines, 8 in. wide, between through-travel lanes; and

u Signs—sometimes illuminated—that read“Pedestrian Crossing” or “School Warning.”

When activated, the HAWK provides a red indica-tion requiring drivers to stop for pedestrians crossingthe major roadway. In Tucson, the HAWKs reducepedestrian waiting time with “hot button” or instan-taneous service. The HAWK can be designed to pro-vide synchronization of signals on the arterial street.

Safety Effectiveness of the HAWK or Pedestrian Hybrid BeaconKAY F I T Z P A T R I C K

R E S E A R C H PAY S O F F

Example of a HAWKtreatment in Tucson,Arizona. [Note: Thepedestrian is RichardNassi, developer of theHAWK.]

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Anecdotal experience indicates that the HAWKdevice improves safety. A comprehensive evaluationwas needed, however, to establish the beacon’s effec-tiveness.

SolutionThe Federal Highway Administration (FHWA) spon-sored a study that used a before-and-after, empiricalBayes approach to evaluate the safety effectiveness ofthe HAWK device (4, 5).The empirical Bayes methodis a statistical approach that determines the effec-tiveness of a treatment from external factors—suchas increases in traffic volumes—and from the ran-domness of crashes. Data were collected on crashesand traffic volume at 102 unsignalized intersectionsthat served as the control sites and at 21 HAWK sites,typically 3 years before and 3 years after the instal-lation. The number of observed crashes that occurredafter the installation of a HAWK was then comparedwith the predicted number of crashes if the treatmenthad not been installed.

The researchers found the following changes incrashes after installation of the HAWK:

u A 69 percent reduction in crashes involvingpedestrians, statistically significant at a 95 percentconfidence level;

u A 15 percent reduction in severe crashes thatresult in injury; this was not statistically significantat a 95 percent confidence level, probably because ofthe low number of these types of crashes; and

u A 29 percent reduction in total crashes, statis-tically significant at a 95 percent confidence level.

ApplicationThe 2009 MUTCD provides the information neededto make decisions about the installation and opera-tion of pedestrian hybrid beacons. According to theguidance, “When an engineering study finds thatinstallation of a pedestrian hybrid beacon is justified,then . . . the pedestrian hybrid beacon should beinstalled at least 100 feet from side streets or drive-ways that are controlled by STOP or YIELD signs” (2,Section 4F.02).

All 21 HAWKs in the safety study were located ata minor intersection, with the minor street controlledby a stop sign, or at a major driveway controlled bya stop sign. In June 2011, the National Committee onUniform Traffic Control Devices, which proposesrevisions and interpretations of the MUTCD, rec-ommended removal of the directive specifying instal-lation at a 100-ft distance.

BenefitThis study showed that the HAWK beacons provided

significant reductions in total crashes and in crashesinvolving pedestrians. Compared with a traffic signal,the HAWK beacon provides faster service to pedes-trians and less delay to motorists—drivers areallowed to proceed on the flashing red after pedes-trians have crossed their half of the roadway; more-over, the beacon costs about half as much as a trafficsignal. As a result, the pedestrian hybrid beacon israpidly gaining acceptance; in addition to Tucson,more than 14 cities have installed the device. TheTucson area currently has more than 100 installa-tions.

The pedestrian hybrid beacon is a proven coun-termeasure that increases pedestrian safety at cross-ings with high volumes, that have wide streets, orthat have high operating speeds.

For more information, contact Kay Fitzpatrick,Senior Research Engineer, Texas Transportation Insti-tute, State Headquarters Research Building, Texas A&MUniversity Research Park, College Station, TX 77843-3135; phone 979-845-7321; kfitzpatrick@ tamu.edu.

References1. Fitzpatrick, K., S. Turner, M. Brewer, P. Carlson, N. Lalani,

B. Ullman, N. Trout, E. S. Park, D. Lord, and J. Whitacre.TCRP Report 112–NCHRP Report 562: Improving PedestrianSafety at Unsignalized Crossings. Transportation ResearchBoard of the National Academies, Washington, D.C., 2006.http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_562.pdf.

2. Manual on Uniform Traffic Control Devices. Federal High-way Administration, Washington, D.C., 2009. http://mutcd.fhwa.dot.gov/kno_2009.htm.

3. Nassi, R. B., and M. J. Barton. New Traffic Control for anOld Pedestrian Crossing Safety Problem. APWA Reporter,June 2008, pp. 44–49.

4. Fitzpatrick, K., and E. S. Park. Safety Effectiveness of theHAWK Pedestrian Crossing Treatment. FHWA-HRT-10-042.Federal Highway Administration, Washington, D.C., 2010.http://www.fhwa.dot.gov/publications/research/safety/10042/10042.pdf.

5. Fitzpatrick, K., and E. S. Park. Safety Effectiveness of theHAWK Pedestrian Treatment. In Transportation ResearchRecord: Journal of the Transportation Research Board, No.2140, Transportation Research Board of the National Acad-emies, Washington, D.C., 2009, pp. 214–223.

EDITOR’S NOTE: Appreciation is expressed to RussellHouston, B. Ray Derr, and G. P. Jayaprakash, Trans-portation Research Board, for their efforts in devel-oping this article.

Suggestions for Research Pays Off topics are wel-come. Contact G. P. Jayaprakash, TransportationResearch Board, Keck 488, 500 Fifth Street, NW, Washington, DC 20001 (202-334-2952;gjayaprakash@nas.edu).

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