The effect of assuming static or dynamic gaze behaviour on the estimated background luminance of drivers

Abstract

Application of the CIE system for mesopic photometry requires that an estimate is made of the observers state of luminance adaptation. This article addresses an assumption made when estimating background luminance, a component of adaptation luminance. Specifically, using spatial sampling of the visual field we compare background luminances determined from assumptions of static and dynamic visual gaze, the former being a simplification, the latter being a better representation based on eye movement when driving. The comparison was undertaken with luminance images of urban scenes at night on three roads, two real and one simulated. It was found that background luminances were significantly higher when estimated using the dynamic assumption. It was also found that scene luminances at the point of foveal fixations tend to be higher than those luminances influencing peripheral regions of the retina. Compared with the background luminance estimated for a dynamic peripheral field, a horizon-centred 10° circle led to a slightly higher estimate and the road surface luminance to a slightly lower estimate.

A Novel Way of Optimizing Headlight Distributions Based on Real Life Traffic and Eye Tracking Data Part 1: Idealized Baseline Distribution

“…This narrow age distribution was chosen specifically to minimize the influence of age in the results. Multiple previous studies [12,14,17,18,23,24] with similar objectives to the present study have used approximately the same or fewer experimental participants as the number used in this part of the study (n = 19).…”

“…Furthermore, with the availability of light sources such as LEDs and lasers, possibilities for optimizing headlight distributions in terms of homogeneity and intensity have changed drastically. Numerous investigations have occurred in recent years regarding the visibility requirements from advanced headlight systems and illumination requirements for visibility and visually guided behavior at night MÜLLER, ROSENHAHN, KANNA, ERKAN, REAGAN, FUNK, WALDNER, CENGIZ, WINTER [8][9][10][11][12][13][14][15][16][17][18] While MOISEL has proposed some initial optimizations [19], the present series of papers will go into further detail.…”

Influence of text luminance, text colour and background luminance of variable-message signs on legibility in urban areas at night

“…The difference in the luminances will inevitably affect the visibility of the VMS to the driver. 32 To understand the background luminance of VMSs and provide the basic luminance data for the experiment, we measured the background luminance of VMSs in the downtown area of Chongqing city with reference to the L 20 method. The L 20 method was recommended by the International Commission on Illumination (CIE) to calculate the luminance outside a tunnel.…”

A Novel Way of Optimizing Headlight Distributions Based on Real-Life Traffic and Eye Tracking Data Part 3: Driver Gaze Behaviour on Real Roads and Optimized Light Distribution

“…Since the science of tracking drivers' gaze behaviour has been evolving since at least 1972 [2], much work has been published over the last 50 years. In recent years, there have been numerous investigations into visibility from advanced headlighting systems and on the illumination requirements for visually guided behaviour [3][4][5][6][7][8][9][10][11][12][13]. Many different topics have been investigated such as the difference of gaze orientation between experienced and inexperienced drivers [2], orientation behaviour when cornering [14], and gaze directions of tired versus vigilant drivers [15].…”