This report contains a further analysis of the experimental study that has previously been carried out. The analysis consists of the following parts: (1) the validation of the developed computer program for determining the "luminance veil" at tunnel entrances; (2) an additional analysis of the results of experiments that have been conducted in the Drecht tunnel in the Dutch municipality of Dordrecht; and (3) a comparison of these results with studies that have been performed in France, Germany, and Canada. The relationship between the contrast as measured in the laboratory, and the contrast "in the field" is called the field factor. This factor represents the fact that the perceiver in a traffic situation is at the same time the motor vehicle driver. The report aims to determine the field factor. It appears that at this moment the computer program cannot be used as a standard method for the design of the long tunnels' entrance lighting. It is recommended to temporarily use the program as an additional tool for that purpose. See also IRRD 834873 (B 30706).
Abstract