# 17-31-088

access zone luminance

average of the luminances contained in a conical part of the field of vision, subtending an angle of 20° at the eye of the approaching driver and centred on a point at a height of one quarter of the height of the tunnel mouth

Note 1 to entry: This entry was numbered 17-9 in CIE S 017:2011.

Publication date: 2020-12