Citation

King LE. Transp. Res. Rec. 1985; 1027: 72-77.

Copyright

(Copyright © 1985, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Recommended roadway lighting practices are set forth in the 1983 American National Standard Practice for Roadway Lighting. In the past, horizontal illuminance has been recognized in the 1983 Standard Practice as the basis for design of roadway lighting. However, lighting engineers have long known that pavement luminance and veiling luminance criteria provide a better correlation with roadway lighting as perceived by the driver. In the 1983 Standard Practice, luminance is recognized as the primary and preferred basis for design, and values for luminance and veiling are recommended. Illuminance criteria are retained as an acceptable alternative. A microcomputer program has been developed for use with the Standard Practice. The program calculates values for illuminance, luminance, and veiling luminance by using input data that include pavement directional reflectance factors, lamp/luminaire candlepower arrays, and geometry of the lighting system. These values are calculated at regularly spaced test points between two adjacent luminaires. For luminance and veiling luminance calculations, the observer moves through the system viewing the roadway at a fixed distance ahead. All calculations are carried out by using formulas and procedures recognized in the Standard Practice, and the output includes values for both the illuminance and luminance design criteria that are contained in the Standard Practice. Written in Microsoft BASIC-80, the program requires a control program for microcomputers, a disk operating system, a RAM of at least 64K, and two disk drives.

Language: en

Keywords

STREET LIGHTING; ELECTRIC LIGHTING - Glare; ILLUMINATING ENGINEERING - Computer Applications; LIGHT - Measurements