Evaluation of LED vehicular and pedestrian modules.

0197-9191PDFTech ReportFHWA-ICT-09-043ICT-09-043, UILU-ENG-2009-2014ICT-R43Signal lightsSignal devicesCommunication devicesTechnology assessmentTechnological innovationsUnited StatesIllinois Center for TransportationHajbabaie, AliBenekohal, Rahim F.Medina, Juan C.Chitturi, MadhavIllinois Center for TransportationIllinois. Dept. of Transportation. Bureau of Materials and Physical ResearchNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic Control DevicesNTL-PEDESTRIAN AND BICYCLES-PedestriansNTL-SAFETY AND SECURITY-SAFETY AND SECURITYUS Transportation CollectionThis study was conducted to verify the compliance of vehicular and pedestrian LED traffic signal modules with the Instituteof Transportation Engineers specifications; and to assess drivers\ue2\u20ac\u2122 preferences of the LED modules. Four vehicular modules(ACS, Dialight, Leotek, and Lumination) and three pedestrian LED modules (Dialight, Leotek, and Lumination) were used.The compliance verification primarily involved reviewing the independent-lab testing reports, visual inspection of themodules, and analyzing the manufacturers\ue2\u20ac\u2122 responses to the questionnaires prepared by the research team. The solid LEDmodules provided by ASC had several issues with compliance with the ITE specification; however, the modules from othercompanies either complied or complied with reservation with all the ITE Specifications. No general conclusion were madefor the arrow modules since at the time of completion of this study, ITE had not adopted a final specification for them. Forpedestrian modules, all companies submitted independent lab test reports for some of the modules, but not for all. Thereports showed that all these modules either complied with, or complied with reservation with most of the ITE specifications.To assess drivers\ue2\u20ac\u2122 preferences, 120 drivers participated in the evaluation of the modules. For solid modules in daytime, theparticipants\ue2\u20ac\u2122 ratings for the ASC were significantly higher than the other three companies. In nighttime, the ASC red modulewas rated much brighter than the Leotek module. However, for solid yellow and green modules, the brightness was ratedthe same for all companies. For red arrow modules in daytime when looking straight ahead, Dialight was rated similar toASC, but significantly higher than Lumination and Leotek. However, for yellow and green arrows, Dialight was rated higherthan all other three companies were. For all three colors of the arrow modules in daytime when looking at an angle, Dialightand ASC were rated significantly higher than Leotek and Lumination. For the pedestrian modules in daytime, the separate12\ue2\u20ac? Dialight module was rated significantly higher than the Leotek and Lumination modules. For 12\ue2\u20ac? combination modules,Leotek and Dialight were rated higher than Lumination. For the 16\ue2\u20ac?*18\ue2\u20ac? combination modules, Lumination was ratedsignificantly higher than Dialight. In rating the traffic modules, all of the respondents chose brightness, 93% chose color,and 88% selected uniformity as an important factor. The most important factor was brightness for 74%, color for 26%, anduniformity for 27% of the participants. In rating of the pedestrian modules, all of the respondents chose brightness, 94%chose color, 90% selected uniformity, and 70% selected size as an important factor. The most important factor wasbrightness for 75%, color for 25%, uniformity for 25%, and size for 23% of the participants