EFFECTS OF PARTIAL LIGHTING ON TRAFFIC OPERATIONS AT FREEWAY INTERCHANGES

The objective of this research was to determine the effectiveness of partial lighting of interchanges in comparison to complete interchange lighting and no lighting and to develop recommendations for its use. Two interchanges with modern geometric design and modern complete interchange lighting (CIL) systems were identified. Permission was obtained from the highway lighting authorities to temporarily modify each lighting system so that various levels of partial interchange lighting (PIL) and no lighting conditions could be provided. The paper is organized into five parts: experimental design, which includes site selection, definition of independent variables and selection of dependent measures; design and development of the data collection system; installation of equipment and data collection; data analysis and results; and interpretation and conclusions.