Development of Headlight System Performance Criteria

摘要

The principal objectives of this research were to identify the levels ofheadlight system illumination needed for safe driving and to specify these illumination requirements in terms of a vehicle coordinate system. Further, software was to be developed to provide a means of determining whether a Roadway Illumination System (RIS) defined by one or more lamps mounted with a specified height and spacing would meet the requirements specified. Specifically, the goals of the research were to determine (through the use of visibility models) the illumination requirements for visibility of roadway targets and the limits upon illumination necessary so that drivers are comfortable with the level of glare. A method was needed to translate driver performance criteria into a roadway illumination performance requirement (RIPR) and a computer program was to be developed to evaluate the degree to which a roadway illumination pattern provided by a given RIS met the criteria specified by the standard. The TEST RIPR proposed by this research intended to illustrate the capabilities of the software and the methodology. It was derived from a determination of both the minimum illumination requirements for the visibility of targets related to safety, and the maximum desirable illumination levels with regard to discomfort glare from mirrors and an oncoming vehicle. Both minimum and maximum requirements consider variation in vehicle dimensions and roadway geometry. Conflicts between minimum and maximum illumination requirements were resolved by generalizing some principals determined in a review of driver needs.