Visibility Performance Requirements and Testing Procedures for Pedestrian Signal Heads;Research rept. Sep 02-Aug 03

摘要

Historically, pedestrian signal heads have been internally illuminated using incandescent lamps. However, with the current widespread use of light emitting diodes (LEDs) in pedestrian signal heads, concerns regarding the visibility of LED devices have emerged. Research was needed to develop measurable visibility performance requirements for pedestrian signal heads, as well as test methods to verify compliance with these requirements.