1、Warning LightsGuidelines for the Selection and Application of on Roadway Operations EquipmentAMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALSii | Guidelines for the Selection and Application of Warning Lights on Roadway Operations Equipment 2009, by American Association of State Hi
2、ghway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Publication Code: WL-1ISBN: 978-1-56051-471-8 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.| iiiAm
3、ericAn AssociAtion of stAte HigHwAy And trAnsportAtion officiAlsexecutive committee20092010President: Larry “Butch” Brown, MississippiVice President: Susan Martinovich, NevadaSecretary/Treasurer: Carlos Braceras, UtahRegional RepresentativesREGION I Joseph Marie, Connecticut Gabe Klein, District of
4、Columbia REGION II Dan Flowers, Arkansas Mike Hancock, Kentucky REGION III Nancy J. Richardson, Iowa Thomas K. Sorel, Minnesota REGION IV Paula Hammond, Washington Amadeo Saenz, Jr., Texas Non-Voting MembersImmediate Past President: Allen Biehler, PennsylvaniaExecutive Director: John Horsley, Washin
5、gton, DCequipment focus Group 2009Ron Pruitt Alabama DOTMike Malcom Georgia DOTJaci Vogel Kansas DOTPeter Carttar Kansas DOTMark McConnell Mississippi DOT Mike Mattison Nebraska DORBill Hoffman Nevada DOT Steven McCarthy Utah DOT, Vice ChairErle Potter Virginia DOT, Chair 2009 by the American Associ
6、ation of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.iv | Guidelines for the Selection and Application of Warning Lights on Roadway Operations EquipmentSTATE MEMBERSALABAMA, George H. Conner, P.E., G. Mike Harper, Ronald D. PruittALAsk
7、A, Michael CoffeeyARIzONA, Marwan Aouad, Lonnie D. HendrixARKANSAS, Emanual Banks, Tony SullivanCALIFORNIA, Randell H. Iwasaki, Alan R. Mills, Steve TakigawaCOLORADO, David C. Wieder, P.E.CONNECTICUT, Richard Baron, Robert P. MongilloDELAWARE, Maria FantiniDISTRICT OF COLUMBIA, Aaron Horton, Mesfin
8、LakewFLORIDA, Tim LattnerGEORGIA, Eric PittsHAWAii, John WilliamsIDAHO, Brent Jennings, P.E.,Steve SpooriLLinois, Aaron WeatherholtINDIANA, Mike BowmanioWA, Bob Younie, P.E.kAnsAs, Peter Carttar, P.E.,Tim D. Cunningham, Roy D. Rissky, P.E.KENTUCKY, Nancy B. AlbrightLOUISIANA, William Drake, Jr.,Gill
9、 M. Gautreau, Janice P. Williams, P.E.MAINE, David B. Bernhardt, Brian T. Burne, Michael E. Burns, John E. BuxtonMARYLAND, Russell A. YurekMASSACHUSETTS, Ron Dionne, Thomas LoughlinMICHIGAN, Jon W. Reincke, P.E.MINNESOTA, Steven M. Lund, Susan J. Lodahl, P.E.MISSISSIPPI, John D. Vance, Celina Sumral
10、lMISSOURI, Don Hillis, P.E., James CarneyMONTANA, Jon swartzNEBRASKA, Craig R. Lind,Michael R. Mattison, P.E.NEVADA, Richard J. Nelson, P.E.,William Hoffman, P.E.NEW HAMPSHIRE, Caleb B. Dobbins, P.E., Douglas GoslingNEW JERSEY, Jeffrey C. Callahan,NEW MExICO, Dennis OrtizNEW YORK, Gary R. McVoy, Ph.
11、D.,Peter WeykampNORTH CAROLINA, Lacy D. Love, P.E., Jennifer P. Brandenburg, P.E.NORTH DAKOTA, Brad DarroHio, Michael A. McColeman,David Ray, P.E., P.S., Keith C. swearingenOKLAHOMA, Kevin S. Bloss,Tom WadleyOREGON, Lucinda M. MoorePEnnsyLvAniA, W. James Smith, Daryl R. St. ClairPUERTO RICO, Juan Av
12、iles- Hernndez, P.E.RHODE ISLAND, Paul R. Annarummo, P.E.SOUTH CAROLINA, James J. Feda, P.E.SOUTH DAKOTA, Jason Humphrey, Ed RodgersTEnnEssEE, Greg Duncan, Joe HoltTExAS, Toribio Garza, Jr., P.E.UTAH, Richard L. Clarke, P.E., Steven J. McCarthyVERMONT, Scott A. Rogers, P.E., Paul E. CortiVIRGINIA, A
13、nwar S. Ahmad, P.E., Erle W. Potter, P.E., C.E.M, Robert E. Prezioso, P.E.WAsHingTon, Robert “Chris” Christopher, P.E. WEST VIRGINIA, Steven B. ColeWISCONSIN, David I. Vieth, John Kinar, Thomas R. Lorfeld, P.E.WYOMING, Ken L. Shultz, P.E.U.S. DOT MEMBERS FHWA William Beatte, Wade Casey, Celso Gatcha
14、lian, Eugene Hoelker, Peter Kopac, Mike Moravec, Steve Mueller, Christopher Newman, Paul PisanoAASHTO Mark S. Bush, P.E., P.T.O.E.Associate MembersInternationalBRITISH COLUMBIA, Rodney ChapmanNEW BRUNSWICK, Henry PalmerNOVA SCOTIA, Bruce FitznerONTARIO, Jeff Baker SASKATCHEWAN, Brent Marjerison, P.E
15、.OTHERTRB, Amir N. Hanna, Frank LisleHiGHWay subcommittee on maintenance 2009Chair: Carlos Braceras, P.E., UtahVice Chair: Lacy D. Love, North CarolinaSecretary: VacantAASHTO Liaison: Ken Kobetsky, P.E. 2009 by the American Association of State Highway and Transportation Officials.All rights reserve
16、d. Duplication is a violation of applicable law.| vtabLe of contentspreface viintroduction . 1safety issues . 3maintenance Vehicle and crew . 3other drivers 4lighting issues and considerations . 5Vehicle color. 5environmental issues 5Adverse weather 5Ambient light . 5Visually complex environments .
17、6lighting selection . 7light source selection 7signal colors 7light type selection 7flashing lights . 7steady lights 7lighting layout and positioning 8Retroreflective Tape 8effective intensity requirements 8Sample Specifications . 11physical requirements . 11functional requirements . 12lighting perf
18、ormance requirements . 12list of Appendices . Back cover 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.vi | Guidelines for the Selection and Application of Warning Lights on Roadway Operations Equipmen
19、tprefaceThe application of warning lights on roadway operations equipment has been a con-cern of many agencies and, over the years, has resulted in a variety of applications. As a result, NCHRP Project 13-02 was funded to develop a recommended set of guidelines based on the effects on the responsive
20、ness of motorists to warning lights on roadways. The basic results of the study have been reviewed and the guide has been approved by AASHTO for consideration for use by the member departments. 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplic
21、ation is a violation of applicable law.| 1introductionRoadway operations equipment used for construction, maintenance, utility work, and other similar activities generally operates within the roadway right-of-way. These vehicles and mobile equipment operate on all types of roadways, during daytime a
22、nd nighttime hours, and under all weather conditions. To improve motorist and work-crew safety, equipment must be readily seen and recognized and, there-fore, warning lights are provided on the equipment to alert motorists of potentially hazardous situations. Amber warning lights have traditionally
23、been used, although lights of other colors are often added with the intent of helping the traveling public better see the equipment. Combinations of amber, blue, and white lights and other forms of warning lights (e.g., lighted bars, lighted “arrow sticks,” strobes, light emitting diodes LED, and al
24、ternating flashes) are used. There is a concern that this variety of light-ing on roadway operations equipment has evolved without adequate consideration of the effects on the awareness and responsiveness of motorists.These guidelines have been developed based on the results of a series of experimen
25、ts that considered more than 40 lighting configurations in both static and dynamic environments. The presence of main-tenance personnel, the identification of the maintenance vehicle, attention-getting, glare, peripheral detection, and urgency were all metrics in the experiments. Differing experimen
26、tal conditions such as weather, the presence of other vehicles, and time of day were also considered in the experiments. 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.2 | Guidelines for the Selection a
27、nd Application of Warning Lights on Roadway Operations EquipmentOne of the primary considerations in the use of these guidelines is the purpose of the maintenance ve-hicle. For the purposes of these guidelines, the term “maintenance vehicle” refers to any type of vehicle used on the roadway, whether
28、 it is being used for new construction, inspection, or general maintenance. The design of the warning-light systems may differ based on the vehicles intended usage. For example, a snow plow will have different criteria than a small truck. The following are typical questions to be considered:Will the
29、 vehicle be used primarily while moving or stopped?Will the vehicle be used primarily in the daytime or nighttime?Will the vehicle be used primarily in bad weather or good weather?Will there be maintenance workers present around the vehicle as pedestrians?Many vehicles are multi-purpose (i.e., they
30、are used for many different tasks on the roadway). For example, a vehicle may be used for clearing snow in the winter and in construction and maintenance activities during the summer. The lighting system on these vehicles needs to be designed and laid out to include the considerations for all of the
31、 planned or expected vehicle uses. 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.| safety issuesSafety with respect to maintenance vehicles must consider not only the maintenance vehicle and its crew b
32、ut also the safety of other drivers.maintenance veHicLe and creWThe safety of the maintenance vehicle crew has two conditions to be considered: when the maintenance crew is in the vehicle and when one or more crew members is outside of the vehicle, possibly working on the road.For the case in which
33、the maintenance crew is in the vehicle, the key to safety is to make the vehicle as conspicuous as possible (i.e., the maintenance vehicle and its actions and purpose are able to be per-ceived by other roadway users). For the case in which the maintenance crew is outside of the vehicle, a higher eff
34、ective-intensity light source was found to hinder safety by limiting the detection of a pedestrian around a vehicle. This factor will limit the overall intensity of the system. Using too many lights or lights with too high effective intensity may impede the ability of other drivers to detect a pedes
35、trian; limiting the effective intensity of the light sources on the vehicle will mitigate this issue.For the vehicle conspicuity, one of the requirements that was first identified in the research was the use of internally illuminated sources. Passive devices, such as retroreflective tape, did not dr
36、aw the drivers attention or provide any attention-getting cues to an approaching vehicle. The warning system must provide active illumination for vehicle safety.Flashing lights were found in the research record to be more conspicuous than continuous lights and provided a sense of urgency. An asynchr
37、onous flashing pattern (flashing side to side) also provided a higher attention-getting rating than a synchronous flash pattern (both sides flashing at once). Finally, amber light sources and white light sources also provided better responses than blue or red. Another issue with the color is the rel
38、ationship of the color to the vehicle type. Amber and white were more commonly identified with maintenance vehicles, while blue and red were identified with police and fire services. Light sources with a higher effective intensity will provide better attention-getting than a light source with a lowe
39、r effective intensity. However, this was offset by the flash characteristics. A flash that provides a different flash pattern than the other lighting systems in the road environment allowed the 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplic
40、ation is a violation of applicable law. | Guidelines for the Selection and Application of Warning Lights on Roadway Operations Equipmentdriver to identify the vehicle sooner than a flash pattern that is similar to other lighting systems being used. Using a double flash or varying the effective inten
41、sity (such as with a rotating beacon) allowed the maintenance vehicle to be identified at a longer distance than other flash patterns. Also, when a vehicle is approached from the rear, the tail lights are primarily used for vehicle identification; locating the warning-light system high on the vehicl
42、e away from the tail lights improved vehicle identification.Another consideration for vehicle safety was the time of day. The appearance of a lighting system against the sky limited the performance of the lighting system. For operation in daytime, it is important that the background behind the light
43、ing system be controlled by having the light appear either against the rear of the vehicle or against a shield that provides adequate contrast and maintains the performance of the lighting system. otHer driversGlare is the primary issue of a warning-light system for other drivers. Bright warning lig
44、hts and op-pressive flashing provide disability glare and discomfort glare for a driver of an oncoming vehicle or a vehicle passing a maintenance vehicle from behind. The warning-light system may limit the driver of another vehicles ability to travel safely.The glare is primarily a result of the int
45、ensity of the light source. The research showed that a high-ef-fective-intensity light source created a greater glare response than a low-effective-intensity light source. A high-effective-intensity light source limited the ability of an approaching driver to see the pedestrian standing behind the m
46、aintenance vehicle. Glare and pedestrian detection also limit the maximum effec-tive intensity of the warning-light system and limit the number and type of light sources placed on the maintenance vehicle.The position of the warning-light system also impacts glare. The research showed that a light po
47、sitioned close to the height of an opposing drivers line of sight created a greater glare response than a high-mounted lighting system. This response was particularly evident with 360 sources (lights that are seen from all angles), as a passing driver will be able to see that source even when they a
48、re very close to the maintenance vehicle. This consideration requires locating the light system as high on the vehicle as possible. 2009 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.| lighting issues and c
49、onsiderationsNot only must the characteristics of maintenance-vehicle lighting systems be considered in terms of safety, but they also must be considered in terms of vehicle design and usage.veHicLe coLorVehicle color was not evaluated in this project. Nevertheless, principles of vision science indicate that a higher contrast between the vehicle color and the light color will provide better visibility. For example, if the vehicle color is white, use of white warning lights should be avoided. A black background for the light source may provide the best poss
