Practical limitations and measurements for camera based road luminance/lighting standards assessment

Modern roadway lighting schemes are designed prior to installation with com puter software. The acceptance criteria have been traditionally based on lu minance, illuminance, and glare levels. However, a new lighting quality cri teria based on a visibility concept has been recently proposed. These desig ns can be achieved with reasonable ease, though discrepancies between theor etical designs and actual lighting installation are inevitable due to varia tions in lighting parameters throughout an installation's lifetime, i.e., v ariation in roadway surface reflectance, alteration of the surrounding envi ronment (trees, buildings, etc.), lamp lumen depreciation, etc. Fundamental to the success of the application is an accurate knowledge of p osition relative to roadway edge and street furniture. This requirement is addressed and results from lighting schemes are analyzed and compared with theoretical predictions.