Pub Date : 2023-01-20DOI: 10.1177/14771535221147312
HR Kang, C-S Lee, Jm Lee, K-M Lee
A phantom array can be observed when there are saccadic eye movements across a time-modulated light source. In this study, the highest frequency limit of the phantom array effect that can be observed was investigated using an LED light source by estimating the participant’s threshold frequency for the visibility of the phantom array effect using the weighted up-down method. A high luminance, narrow slit, warm white LED, and long saccadic eye movement range were used as the experimental stimuli and conditions. The mean threshold frequency for young adults was approximately 10 kHz under the proposed experimental conditions. The phantom array effect was observed even above 15 kHz in the high threshold frequency group when we divided participants into three groups according to the threshold frequency. In addition, the high threshold frequency group showed a higher eye movement speed than the other groups.
{"title":"Phantom array effect can be observed above 15 kHz in high speed eye movement group for high luminance warm white LED","authors":"HR Kang, C-S Lee, Jm Lee, K-M Lee","doi":"10.1177/14771535221147312","DOIUrl":"https://doi.org/10.1177/14771535221147312","url":null,"abstract":"A phantom array can be observed when there are saccadic eye movements across a time-modulated light source. In this study, the highest frequency limit of the phantom array effect that can be observed was investigated using an LED light source by estimating the participant’s threshold frequency for the visibility of the phantom array effect using the weighted up-down method. A high luminance, narrow slit, warm white LED, and long saccadic eye movement range were used as the experimental stimuli and conditions. The mean threshold frequency for young adults was approximately 10 kHz under the proposed experimental conditions. The phantom array effect was observed even above 15 kHz in the high threshold frequency group when we divided participants into three groups according to the threshold frequency. In addition, the high threshold frequency group showed a higher eye movement speed than the other groups.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131236808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.1177/14771535221138589
Y. Li, W. Fang, B. Guo, H. Qiu
This study investigated the non-image forming (NIF) effects of dynamic light on alertness, cognitive performance and mood on mental fatigue, as well as moderation of task difficulty in lighting perception. Sixteen participants completed a psychomotor vigilance test (PVT) and two complex cognitive tasks (multi-attribute task battery-II (MATB-II) and n-back) with low, medium and high difficulty levels under dynamic (4000 to 12 000 K, melanopic equivalent daylight illuminance (EDI) = 224 lx to 420 lx) and static (4000 K, melanopic EDI = 224 lx) lighting with illuminance set at 500 lx on the desk. Psychological, behavioural, biochemical and electrophysiological responses to light were assessed. The results showed that exposure to dynamic light had significant benefits on subjective sleepiness, positive mood and task performance, which may be moderated by task difficulty. The intervention effect of dynamic light on fatigue was also found during an electrophysiological activity due to increase in the amount of attentional resources allocated to the tasks by dynamic light, but was not observed in biochemical measures.
{"title":"Diurnal effects of dynamic lighting on alertness, cognition, and mood of mentally fatigued individuals in a daylight deprived environment","authors":"Y. Li, W. Fang, B. Guo, H. Qiu","doi":"10.1177/14771535221138589","DOIUrl":"https://doi.org/10.1177/14771535221138589","url":null,"abstract":"This study investigated the non-image forming (NIF) effects of dynamic light on alertness, cognitive performance and mood on mental fatigue, as well as moderation of task difficulty in lighting perception. Sixteen participants completed a psychomotor vigilance test (PVT) and two complex cognitive tasks (multi-attribute task battery-II (MATB-II) and n-back) with low, medium and high difficulty levels under dynamic (4000 to 12 000 K, melanopic equivalent daylight illuminance (EDI) = 224 lx to 420 lx) and static (4000 K, melanopic EDI = 224 lx) lighting with illuminance set at 500 lx on the desk. Psychological, behavioural, biochemical and electrophysiological responses to light were assessed. The results showed that exposure to dynamic light had significant benefits on subjective sleepiness, positive mood and task performance, which may be moderated by task difficulty. The intervention effect of dynamic light on fatigue was also found during an electrophysiological activity due to increase in the amount of attentional resources allocated to the tasks by dynamic light, but was not observed in biochemical measures.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133730183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-22DOI: 10.1177/14771535221142812
M. Gkaintatzi-Masouti, J. van Duijnhoven, Mpj Aarts
Light affects many aspects of human physiology, through the non-image-forming (NIF) pathway. To account for this pathway, lighting design simulation tools need to combine several luminous and temporal factors to predict how architectural and lighting design decisions affect eye-level light exposure. Based on a systematic literature review, containing 55 journal and conference papers, the state-of-the-art towards implementing lighting beyond vision in computer simulation workflows for building design is presented. The review shows that, while interest in simulating the NIF effects of light on people is increasing, there is not a common method to perform these simulations. Gaps were identified in the currently available simulation workflows in relation to metrics, software and approaches for predicting NIF effects of light in the context of the building design.
{"title":"Simulations of non-image-forming effects of light in building design: A literature review","authors":"M. Gkaintatzi-Masouti, J. van Duijnhoven, Mpj Aarts","doi":"10.1177/14771535221142812","DOIUrl":"https://doi.org/10.1177/14771535221142812","url":null,"abstract":"Light affects many aspects of human physiology, through the non-image-forming (NIF) pathway. To account for this pathway, lighting design simulation tools need to combine several luminous and temporal factors to predict how architectural and lighting design decisions affect eye-level light exposure. Based on a systematic literature review, containing 55 journal and conference papers, the state-of-the-art towards implementing lighting beyond vision in computer simulation workflows for building design is presented. The review shows that, while interest in simulating the NIF effects of light on people is increasing, there is not a common method to perform these simulations. Gaps were identified in the currently available simulation workflows in relation to metrics, software and approaches for predicting NIF effects of light in the context of the building design.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123515525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-17DOI: 10.1177/14771535221142489
AK Jägerbrand, A. Brutemark
{"title":"Correspondence: Addressing and mitigating the ecological effects of light pollution requires ecological perspectives","authors":"AK Jägerbrand, A. Brutemark","doi":"10.1177/14771535221142489","DOIUrl":"https://doi.org/10.1177/14771535221142489","url":null,"abstract":"","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128470632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-06DOI: 10.1177/14771535221136099
F. Beute, A. Lowden, M. Aries
Social constraints posed by work schedules influence sleep duration and timing. Everyday light exposure can help (or hinder) sleep outcomes. This study investigated the differences in the relationship between light exposure and sleep outcomes on days with and without social constraints using ambulatory assessment for 4–6 weeks for 15 office employees. The effects of light on sleep were investigated for both clock time and wake time (related to individual sleep times). Participants were exposed to more light during the morning and afternoon on workdays, and sleep times were later on days without social constraints. The relationship between light exposure and sleep was more pronounced, or sometimes even only present, for days without social constraints. In addition, no differences were found between clock time and wake time, which underlines the complexity of the relationship between everyday light exposure and sleep. Despite increased light exposure during workdays, the effects of light on sleep were more pronounced on days without social constraints. It may signal that office workers need a more substantial circadian stimulus (i.e. higher light exposure) for light to influence sleep outcomes on days with social constraints.
{"title":"The relationship of light exposure to sleep outcomes among office workers. Part 2: Comparison of days with and without social constraints","authors":"F. Beute, A. Lowden, M. Aries","doi":"10.1177/14771535221136099","DOIUrl":"https://doi.org/10.1177/14771535221136099","url":null,"abstract":"Social constraints posed by work schedules influence sleep duration and timing. Everyday light exposure can help (or hinder) sleep outcomes. This study investigated the differences in the relationship between light exposure and sleep outcomes on days with and without social constraints using ambulatory assessment for 4–6 weeks for 15 office employees. The effects of light on sleep were investigated for both clock time and wake time (related to individual sleep times). Participants were exposed to more light during the morning and afternoon on workdays, and sleep times were later on days without social constraints. The relationship between light exposure and sleep was more pronounced, or sometimes even only present, for days without social constraints. In addition, no differences were found between clock time and wake time, which underlines the complexity of the relationship between everyday light exposure and sleep. Despite increased light exposure during workdays, the effects of light on sleep were more pronounced on days without social constraints. It may signal that office workers need a more substantial circadian stimulus (i.e. higher light exposure) for light to influence sleep outcomes on days with social constraints.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121078289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-15DOI: 10.1177/14771535221093470
K. Hamoodh, S. Fotios, C. Cheal
Pedestrians need to be able to evaluate other people to support their feeling of safety. While past studies have thus investigated the degree to which road lighting supports facial identity and facial emotion evaluations, it is not yet known whether the face is the most important visual cue. Following a pilot study that indicated the importance of the ability to see the face and hands of other people, an experiment was conducted in which test participants evaluated safety when shown photographs of an approaching person in night-time scenes. These photographs displayed variations in the exposure or concealment of the face and hands. Two procedures were used, category rating and paired comparisons. The results suggest that the face is a more important visual cue than the hands for pedestrians’ evaluations of the intent of other pedestrians after dark.
{"title":"Visual cues to interpersonal evaluations for pedestrians","authors":"K. Hamoodh, S. Fotios, C. Cheal","doi":"10.1177/14771535221093470","DOIUrl":"https://doi.org/10.1177/14771535221093470","url":null,"abstract":"Pedestrians need to be able to evaluate other people to support their feeling of safety. While past studies have thus investigated the degree to which road lighting supports facial identity and facial emotion evaluations, it is not yet known whether the face is the most important visual cue. Following a pilot study that indicated the importance of the ability to see the face and hands of other people, an experiment was conducted in which test participants evaluated safety when shown photographs of an approaching person in night-time scenes. These photographs displayed variations in the exposure or concealment of the face and hands. Two procedures were used, category rating and paired comparisons. The results suggest that the face is a more important visual cue than the hands for pedestrians’ evaluations of the intent of other pedestrians after dark.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134062340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-17DOI: 10.1177/14771535221126902
Yu MSc, Wijntjes, Eisemann, S. Pont, Cehao Yu
In everyday scenes, the effective light (the actual light in a space) can be defined as a complex light field, resulting from a mixture of emissive light sources and indirect mutual surface (inter-)reflections. Hence, the light field typically consists of diffuse and directional illumination and varies in spectral irradiance as a function of location and direction. The spatially varying differences between the diffuse and directional illumination spectra induce correlated colour temperature (CCT) and colour rendition variations over the light fields. Here, we aim to investigate the colourimetric properties of the actual light, termed the effective CCT and colour rendition, for spaces of one reflectance (uni-chromatic spaces). The spectra of the diffuse light-field component (light density) and the directional light-field component (light vector) were measured in both physical and simulated uni-chromatic spaces illuminated by ordinary white light sources. We empirically tested the effective CCT and colour rendition for the light density and the light vector, separately. There were significant differences between the lamp-specified CCT and colour rendition and the actual light-based effective CCT and effective colour rendition. Inter-reflections predominantly affected the CCT and colour rendition of the light density relative to the light vector. Treating the diffuse and directional light-field components in a linear model reveals the separate influences of the light source and scene. These effects show the importance of a 3D version of colour checkers for lighting designers, architects or in general computer graphics applications, for which we propose simple Lambertian spheres.
{"title":"Effects of inter-reflections on the correlated colour temperature and colour rendition of the light field","authors":"Yu MSc, Wijntjes, Eisemann, S. Pont, Cehao Yu","doi":"10.1177/14771535221126902","DOIUrl":"https://doi.org/10.1177/14771535221126902","url":null,"abstract":"In everyday scenes, the effective light (the actual light in a space) can be defined as a complex light field, resulting from a mixture of emissive light sources and indirect mutual surface (inter-)reflections. Hence, the light field typically consists of diffuse and directional illumination and varies in spectral irradiance as a function of location and direction. The spatially varying differences between the diffuse and directional illumination spectra induce correlated colour temperature (CCT) and colour rendition variations over the light fields. Here, we aim to investigate the colourimetric properties of the actual light, termed the effective CCT and colour rendition, for spaces of one reflectance (uni-chromatic spaces). The spectra of the diffuse light-field component (light density) and the directional light-field component (light vector) were measured in both physical and simulated uni-chromatic spaces illuminated by ordinary white light sources. We empirically tested the effective CCT and colour rendition for the light density and the light vector, separately. There were significant differences between the lamp-specified CCT and colour rendition and the actual light-based effective CCT and effective colour rendition. Inter-reflections predominantly affected the CCT and colour rendition of the light density relative to the light vector. Treating the diffuse and directional light-field components in a linear model reveals the separate influences of the light source and scene. These effects show the importance of a 3D version of colour checkers for lighting designers, architects or in general computer graphics applications, for which we propose simple Lambertian spheres.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133184585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.1177/14771535221122139
R. Jedon, A. Haans, Y. D. de Kort
The impact of street lighting on the visual tasks of pedestrians is well known, as are studies that have explored the relationship between street lighting and pedestrians’ feelings of safety. But there are other, less investigated, possible effects of light in mesopic situations. Research on street lighting for pedestrians has traditionally focused on visual performance (e.g., obstacle detection, face recognition) and people’s appraisals of the outdoor environment after dark. But the influence of concepts such as alertness and attentiveness on pedestrians’ experience and performance is not yet well researched even though this too can play an important role in pedestrians’ attention and safety. To remedy this, we are offering first a clarification of the relevant constructs – alertness, arousal and anxiety – and proposing a new theoretical framework. Possible benefits of using this conceptual framework are illustrated with an analysis of conclusions from a study conducted by Burtt. We make a case for more research on mechanisms underlying pedestrians’ attention and safety. Implications for future research, in particular the need for validating this framework, are discussed.
{"title":"Proposing a research framework for urban lighting: The alertness, arousal and anxiety triad","authors":"R. Jedon, A. Haans, Y. D. de Kort","doi":"10.1177/14771535221122139","DOIUrl":"https://doi.org/10.1177/14771535221122139","url":null,"abstract":"The impact of street lighting on the visual tasks of pedestrians is well known, as are studies that have explored the relationship between street lighting and pedestrians’ feelings of safety. But there are other, less investigated, possible effects of light in mesopic situations. Research on street lighting for pedestrians has traditionally focused on visual performance (e.g., obstacle detection, face recognition) and people’s appraisals of the outdoor environment after dark. But the influence of concepts such as alertness and attentiveness on pedestrians’ experience and performance is not yet well researched even though this too can play an important role in pedestrians’ attention and safety. To remedy this, we are offering first a clarification of the relevant constructs – alertness, arousal and anxiety – and proposing a new theoretical framework. Possible benefits of using this conceptual framework are illustrated with an analysis of conclusions from a study conducted by Burtt. We make a case for more research on mechanisms underlying pedestrians’ attention and safety. Implications for future research, in particular the need for validating this framework, are discussed.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116001695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1177/14771535221076171
H. Pak, H. Kang, David Song, J.H. Lee, H. Park, C-S Lee
Traffic crashes frequently occur at intersections because drivers or pedestrians cannot properly anticipate the direction towards which other vehicles are turning. A turn signal guide lamp was developed to improve the observer’s direction judgement of turn signals, and experiments were conducted to test the effect of the guide lamp based on behavioural responses. Our experimental results demonstrated that the turning direction judgement response time was reduced when both the turn signal indicators and turn signal guide lamps were used together compared with the case when only the turn signal indicators were used. Supplementary eye-tracking data also demonstrated that the gaze point frequently stayed on the light patterns on the ground marked by the turn signal guide lamps. Additional glare evaluation using the de Boer scale showed no significant difference between the turn signal indicator with a guide lamp and the turn signal indicator alone on dry or wet road surfaces. Therefore, it is expected that the newly developed turn signal guide lamp will increase the observer’s performance of direction judgement on the turn signalling function without causing an additional glare when the observer knows the function of the guide lamp.
{"title":"Evaluation of direction judgements based on turn signal guide lamp and behavioural responses","authors":"H. Pak, H. Kang, David Song, J.H. Lee, H. Park, C-S Lee","doi":"10.1177/14771535221076171","DOIUrl":"https://doi.org/10.1177/14771535221076171","url":null,"abstract":"Traffic crashes frequently occur at intersections because drivers or pedestrians cannot properly anticipate the direction towards which other vehicles are turning. A turn signal guide lamp was developed to improve the observer’s direction judgement of turn signals, and experiments were conducted to test the effect of the guide lamp based on behavioural responses. Our experimental results demonstrated that the turning direction judgement response time was reduced when both the turn signal indicators and turn signal guide lamps were used together compared with the case when only the turn signal indicators were used. Supplementary eye-tracking data also demonstrated that the gaze point frequently stayed on the light patterns on the ground marked by the turn signal guide lamps. Additional glare evaluation using the de Boer scale showed no significant difference between the turn signal indicator with a guide lamp and the turn signal indicator alone on dry or wet road surfaces. Therefore, it is expected that the newly developed turn signal guide lamp will increase the observer’s performance of direction judgement on the turn signalling function without causing an additional glare when the observer knows the function of the guide lamp.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128716599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.1177/14771535221094279
S. Vogel, S. Fiedelak, M. Niedling, S. Völker
Modern high-resolution headlamp systems are capable of adjusting to different driving situations. However, the existing road lighting is not yet taken into account when setting the headlamp’s light distribution. This article investigates the influence of the automotive headlamp systems on the visibility of targets in different road lighting conditions and proposes a new lighting strategy based on these results. The luminances of square targets of different surface reflectances and at different distances ahead of the vehicle were measured in road lighting designed to meet classes varying from M3 to M6. For each combination the visibility level (VL) of the targets was determined, with road lighting alone and also when additionally illuminating the scene with the car headlamps. The influence of the headlamps on target visibility was found to depend on the road lighting class, the target distance and its reflectance. In some situations, additional light from the headlamp decreased the target VL and therefore the probability that a driver would detect it. Different ranges of headlamp light distribution were proposed for different road lighting classes to bring light only where it is needed.
{"title":"Influence of automotive headlamp systems on the visibility of targets under different road lighting conditions","authors":"S. Vogel, S. Fiedelak, M. Niedling, S. Völker","doi":"10.1177/14771535221094279","DOIUrl":"https://doi.org/10.1177/14771535221094279","url":null,"abstract":"Modern high-resolution headlamp systems are capable of adjusting to different driving situations. However, the existing road lighting is not yet taken into account when setting the headlamp’s light distribution. This article investigates the influence of the automotive headlamp systems on the visibility of targets in different road lighting conditions and proposes a new lighting strategy based on these results. The luminances of square targets of different surface reflectances and at different distances ahead of the vehicle were measured in road lighting designed to meet classes varying from M3 to M6. For each combination the visibility level (VL) of the targets was determined, with road lighting alone and also when additionally illuminating the scene with the car headlamps. The influence of the headlamps on target visibility was found to depend on the road lighting class, the target distance and its reflectance. In some situations, additional light from the headlamp decreased the target VL and therefore the probability that a driver would detect it. Different ranges of headlamp light distribution were proposed for different road lighting classes to bring light only where it is needed.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132538999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}