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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Deep Learning Model for Discomfort Glare Detection Based on Occupants’ Facial Analysis</title>
      <link>https://trid.trb.org/View/2640464</link>
      <description><![CDATA[Any building designed for human occupancy needs to be visually comfortable. Glare from daylight is one of the main causes of visual discomfort. Glare perception is evaluated by empirical glare models either by photometric measurements or by lighting simulations. This study explores an alternate solution that implements deep learning methods to develop glare prediction models from video recordings of human faces exposed to different levels of sunlight indoors. We trained and evaluated 12 widely used Convolutional Neural Network (CNN) architectures over a data set of 78 facial videos of 21 human participants experiencing glare in a daylit office-like setup. Results indicate that the best-performing CNN achieves an accuracy of (1) 87% in predicting glare on the repeated participants in unseen lighting conditions of different intensity and (2) 67% on new participants’ faces with previously seen lighting conditions. We propose future research directions to improve predictions from such models.]]></description>
      <pubDate>Wed, 25 Feb 2026 08:54:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/2640464</guid>
    </item>
    <item>
      <title>Exploring contributing factors in single-vehicle truck crashes on rural roads: Accounting for unobserved heterogeneity and role of solar glare</title>
      <link>https://trid.trb.org/View/2655582</link>
      <description><![CDATA[This study investigates the factors that influence single-vehicle large truck crashes on rural roadways using Highway Safety Information System data from the state of Washington from 2014 to 2018. We used a random parameter multinomial logit model with heterogeneity in means and variances to identify significant random parameters, interactions, and factors exhibiting heterogeneity in means. Additionally, a comprehensive process was used to determine which crashes were impacted by solar glare. Two parameters, including driver age over 50 and the absence of airbags in vehicles, were found to be significant random parameters. Results revealed that solar glare effects notably influenced possible injury and nondisabling injuries in single-vehicle truck accidents. Further, factors like collector roads, curved segments, lack of access control, driving without safety restraints, operating defective vehicles, skidding, overturning, and the second quarter of the year increase the likelihood of disabling/fatal injury. The study’s insights enrich the limited literature on single-vehicle large truck crashes on rural roads, enabling policymakers and transportation and logistics agencies to take appropriate safety measures in these areas. This research is crucial for promoting sustainable transportation by addressing the safety challenges associated with large truck operations on rural roads. It can help prevent traffic injuries and improve overall road safety. Enhancing safety can reduce crash-related delays, economic losses, and environmental impacts caused by traffic congestion and vehicle emissions. Recommendations are suggested, including the use of transverse rumble strips and prior signboards to enhance driver alertness and combat driver drowsiness. Additionally, the use of metalized windshields in vehicles to mitigate glare-induced blindness can further improve safety.]]></description>
      <pubDate>Wed, 18 Feb 2026 13:27:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2655582</guid>
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    <item>
      <title>The Effect of Nighttime Lighting Systems on Workers’ Visibility and Safety</title>
      <link>https://trid.trb.org/View/2659348</link>
      <description><![CDATA[Nighttime work zones pose increased risks for both drivers and workers due to the challenge of ensuring adequate visibility while minimizing glare. Current lighting practices vary widely across public agencies, often resulting in excessive illumination and poor glare control. This study evaluated the performance of nighttime lighting systems through two phases: (1) an industry survey and (2) a controlled field experiment along with a qualitative task assessment and analysis. The survey, with 116 responses, identified persistent issues related to glare and uneven light coverage, primarily attributed to improper lighting configurations rather than insufficient light output. The field study tested 126 lighting setups using LED and halogen lighting sources set at varying mounting heights, aiming angles, and rotation angles. Measurements included horizontal and vertical illuminance, pavement luminance, and veiling luminance ratio (VLR). Results showed that the lighting setups—rotation angle and mounting height—had the greatest impact on visibility and glare. Optimal configurations (rotation: 40°–50°, height: 12–13 ft, aiming angle: 20°–40°) could provide better visibility and minimize harmful glare in the vicinity of nighttime work zones. This report provides recommendations for optimal lighting configurations, offering agencies practical guidance to improve safety and visibility in nighttime work zones.]]></description>
      <pubDate>Fri, 06 Feb 2026 13:53:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2659348</guid>
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    <item>
      <title>Flash Blindness Recovery of a Tracking Task on Cockpit Attitude Indicators</title>
      <link>https://trid.trb.org/View/2646923</link>
      <description><![CDATA[Intense light exposures can cause temporary flash blindness, degrading pilot performance during flight. The present study investigated factors influencing time to recover from flash blindness for tasks resembling aircraft control using an attitude indicator. Prior similar studies of flash blindness used only reflective gauges whereas modern cockpits include emissive displays, so recovery differences between reflective and emissive instrument types were of interest as was the influence of varying ambient luminance levels.  Nine subjects performed attitude indicator horizon stabilization and tracking tasks on both a reflective and an emissive attitude indicator. Subjects were exposed to short (150 ms) high intensity broadband light flashes at three retinal exposure levels [6.5, 7.0, and 7.5 log troland-seconds (logTd·s)] beforehand. Additionally, ambient luminance was manipulated (1 cd · m-2, 10 cd · m-2, and 100 cd · m-2). The time to level the horizon after a flash exposure was measured. After leveling, roll and pitch errors made while maintaining straight and level flight by countering added perturbation were also tracked.  Greater flash intensity usually increased recovery time. For the reflective attitude indicator, as ambient luminance increased, flash intensity had weaker influence on recovery times, with recovery times ranging from 6–30 s. For the emissive attitude indicator, however, ambient luminance did not appreciably influence recovery times, with recovery times ranging from 8–16 s.  The reflective attitude indicator was more advantageous for flash blindness recovery in high (100 cd · m-2) ambient luminance and the emissive indicator was relatively more advantageous in low (1 cd · m-2) ambient luminance.]]></description>
      <pubDate>Thu, 29 Jan 2026 17:02:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2646923</guid>
    </item>
    <item>
      <title>Glare from vehicle lighting on UK roads: Literature review</title>
      <link>https://trid.trb.org/View/2635345</link>
      <description><![CDATA[This literature review accompanies the TRL Limited report Glare from vehicle lighting on UK roads (PPR2069).]]></description>
      <pubDate>Thu, 29 Jan 2026 08:52:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2635345</guid>
    </item>
    <item>
      <title>Glare from vehicle lighting on UK roads: on-road measurements of luminance and glare, and a survey with a representative sample of UK drivers</title>
      <link>https://trid.trb.org/View/2635346</link>
      <description><![CDATA[Vehicle lights can cause glare for other drivers. Although the United Kingdom (UK) regulates the luminous intensity of headlights, drivers continue to report problems with glare, especially during night driving. Problems are also associated with technologies such as light emitting diodes (LEDs), especially from oncoming large vehicles. In this study, the authors sought to understand the causes of glare during night driving, and to propose remedies. First, 1,850 drivers participated in a survey, in which they reported their experiences of glare while driving. Then, an instrumented trial vehicle collected data from the normal driver eye position during night driving. Variables that were measured included luminance levels, location, other vehicles in the scene, the trial vehicle’s pitch and roll, and subjective reports of glare from an observer in the trial vehicle. A machine learning algorithm analyzed the data to discover patterns and match variables to high luminance levels and reported glare from the observer. The findings indicated that the drivers regarded glare from vehicle headlights to be an important and extensive issue in night driving. Over 50% reported that they had reduced speed or stopped at night, when possible, due to headlight glare. Data analysis revealed that glare was associated with high luminance levels in the scene, with particular locations, and with particular positions of the trial vehicle. Specific vehicle types in the scene were also associated with the observer reporting glare. The study shows that glare from vehicle lights can be studied using an instrumented vehicle. Several recommendations for further action are made, including public awareness campaigns, further research, and changes to vehicle lights regulation.]]></description>
      <pubDate>Thu, 29 Jan 2026 08:52:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2635346</guid>
    </item>
    <item>
      <title>Assessing Urban Solar Glare from Glass Curtain Walls: Effects of Street Orientation and Building Form on Sustainable Design and Public Safety</title>
      <link>https://trid.trb.org/View/2626421</link>
      <description><![CDATA[High-reflectivity glass in urban high-rises, driven by energy efficiency and aesthetics, creates unforeseen sustainability concerns through daytime solar glare. Reflected sunlight affects visual comfort and traffic safety for pedestrians and drivers. While nighttime light pollution is increasingly addressed, daytime glare remains underexplored in dense cities, posing public safety risks, particularly for elderly and visually sensitive groups. In human-centered urban design, quantifying and managing these risks improves urban livability and social equity. This study presents a simulation-based methodology for assessing solar glare at urban street scale, utilizing reverse-tracing based on modified International Commission on Illumination (CIE) standards. The analysis examined 238 glass curtain wall buildings within 1.5 km of Gangnam Station, Seoul, with measurements across 69 viewpoints along east-west (Street A) and north–south (Street B) routes over 8-hour daily periods. Variables including solar altitude, building height, and facade angle were systematically adjusted. Across sixteen simulation scenarios, glare probabilities differed by orientation: east-west corridors recorded 0.24–11.74% occurrences—driven mainly by solar altitude—with peak frequency at 20–25 m building heights, while north–south corridors ranged 0.46–6.78%, governed chiefly by building height, showing primary peaks at 15 m with additional frequent occurrences at 20–40 m heights. Results suggest lower building heights and tilted facades may reduce glare exposure, with variations depending on street orientation. A spatial glare database was constructed to illustrate locations with higher levels of potential glare, providing practical input for mitigation planning. By connecting environmental simulation with urban design and public safety considerations, this research contributes to planning more sustainable and visually balanced urban environments.]]></description>
      <pubDate>Mon, 26 Jan 2026 14:44:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2626421</guid>
    </item>
    <item>
      <title>Headlight glare in police-reported crash data: prevalence, contributing factors, and potential effects</title>
      <link>https://trid.trb.org/View/2610618</link>
      <description><![CDATA[This study is a based on police reports of traffic crashes, 2015-2024, and examines headlight glare. It looks at the prevalence of headlight glare as a factor associated with nighttime crashes, driver age and sex, and driver response. Headlight glare was reported as a factor in 0.1% to 0.2% of nighttime crashes. Glare-related crashes were more likely to occur on lower-speed two-lane roads, result in a lane departure, and involve an older driver.]]></description>
      <pubDate>Wed, 17 Dec 2025 16:07:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2610618</guid>
    </item>
    <item>
      <title>Glare Mitigation for Enhanced Autonomous Vehicle Perception</title>
      <link>https://trid.trb.org/View/2591711</link>
      <description><![CDATA[Vision sensors are versatile and can capture a wide range of visual cues, such as color, texture, shape, and depth. This versatility, along with the relatively inexpensive availability of machine vision cameras, played an important role in adopting vision-based environment perception systems in autonomous vehicles (AVs). However, vision-based perception systems can be easily affected by glare in the presence of a bright source of light, such as the sun or the headlights of the oncoming vehicle at night or simply by light reflecting off snow or ice-covered surfaces; scenarios encountered frequently during driving. In this paper, we investigate various glare reduction techniques, including the proposed saturated pixel-aware glare reduction technique for improved performance of the computer vision (CV) tasks employed by the perception layer of AVs. We evaluate these glare reduction methods based on various performance metrics of the CV algorithms used by the perception layer. Specifically, we considered object detection, object recognition, object tracking, depth estimation, and lane detection which are crucial for autonomous driving. The experimental findings validate the efficacy of the proposed glare reduction approach, showcasing enhanced performance across diverse perception tasks and remarkable resilience against varying levels of glare.]]></description>
      <pubDate>Mon, 27 Oct 2025 13:56:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2591711</guid>
    </item>
    <item>
      <title>Evaluation of Low Pressure Sodium Vapor Illumination</title>
      <link>https://trid.trb.org/View/2572965</link>
      <description><![CDATA[Low Pressure Sodium (LPS) roadway illumination systems of 35, 55, 90, 135 and 180 watts were studied and compared to Mercury Vapor (MV) and High Pressure Sodium (HPS) roadway illumination systems. Systems of 180-watt LPS, 400-watt HPS, and 1000-watt MV, and systems of 135-watt LPS, 250-watt HPS, and 400-watt MV are compared with respect to photometrics, visual acuity, disability veiling glare, and energy savings. Actual photometric data, including isolux curves are shown as measured on a simulated roadway.]]></description>
      <pubDate>Sat, 27 Sep 2025 13:02:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2572965</guid>
    </item>
    <item>
      <title>Mesopic and glare driving performance in a driving simulator</title>
      <link>https://trid.trb.org/View/2582046</link>
      <description><![CDATA[Difficulties in night driving due to deficits in visual function are a common problem among older drivers. Signage, hazards, and road markings can be more difficult to identify for those with presbyopia, especially in nighttime conditions that include glare from headlights. This study evaluated the visual function and driving abilities of participants in various lighting conditions to find efficient and effective testing procedures for predicting how older individuals will perform in night driving conditions. A driving simulator study was conducted to investigate the relationship between driving performance measures and visual function measures in different lighting conditions. Participants were examined in a laboratory setting to measure visual acuity and contrast sensitivity in bright light, dim light, and dim light with glare conditions. The participants were asked to drive in a driving simulator in simulated day, night, and night with glare conditions. Analysis using a linear mixed model was performed across the lighting conditions. There are statistically significant relationships between the experimental variables, with age being an important factor. Age was found to have a statistically significant effect on the standard deviation of lateral position, which is a measure of vehicle control. Age was also found to have a statistically significant effect on reaction time and accuracy of a secondary identification task. Visual acuity and contrast sensitivity were found to have a statistically significant effect on mean velocity. Results suggest that visual acuity alone is insufficient to fully describe visual function for predicting performance in a driving task, but the ideal variables for prediction of performance in a night driving situation are not clear.]]></description>
      <pubDate>Fri, 19 Sep 2025 16:58:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2582046</guid>
    </item>
    <item>
      <title>SALUSLux: Automation for Safer Pedestrian Street Lighting at Intersections [supporting dataset]</title>
      <link>https://trid.trb.org/View/2591971</link>
      <description><![CDATA[Abstract of the final report is stated below for reference: This study addresses the trade-off between pedestrian visibility, pedestrian safety, and light pollution in nighttime intersection lighting design by analyzing how combinations of light source characteristics (e.g., correlated color temperature, distribution type) and streetlight geometry (e.g., pole height, orientation, offset) affect safety and environmental outcomes. The authors developed SALUSLux, an open-source, Python-based simulation toolset that evaluates realistic lighting conditions using standardized photometric data, simulating 2,304 intersection scenarios across various spatial configurations and light sources. Results reveal that interaction effects between geometry and luminaire properties are critical, with optimized designs— particularly using lower-correlated color temperature sources and a 45° modified turbine configuration— achieving superior visibility and reduced light pollution. Some designs simultaneously maximized safety and environmental performance, challenging assumptions that brighter or high-correlated color temperature lighting is necessary. This work highlights the potential of tools like SALUSLux to enable data-driven, sustainable streetlighting solutions.]]></description>
      <pubDate>Mon, 08 Sep 2025 14:53:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2591971</guid>
    </item>
    <item>
      <title>Glare at Night-Time Driving: Effect of Correlated Color Temperature of LED Lamps</title>
      <link>https://trid.trb.org/View/2549037</link>
      <description><![CDATA[Objective: This study aims to analyze the effect of correlated color temperature from LED glare sources on driving performance. The evaluation includes assessing the effect of disability glare on visual reaction time and rating discomfort glare using a standardized scale. Background: LED technology is widely incorporated into various lighting systems; however, the impact of glare from oncoming car headlamps on driving performance at night-time is crucial for road safety. Method: Twenty-three healthy young subjects participated in a laboratory-based experiment simulating night driving using a two-channel Maxwellian view optical system. Two LED lamps with correlated color temperature of 2800 K and 6500 K were used to generate a glare of 52 lx. Disability glare was quantified in terms of foveal reaction time and discomfort glare was rated using the de Boer scale. Results: The results show that glare-induced effect is mitigated by an increase in background luminance. The correlated color temperature of the LED lamp does not affect either reaction time or discomfort glare rating. Conclusion: The greater short-wavelength emission of 6500 K lamp does not intensify the effect of disability or discomfort glare, probably due to the macular pigment absorption on foveal vision and the transparency of ocular media, coupled with the involvement of other contributing factors. The correlated color temperature of the lamp is not the best descriptive parameter to identify its effect on glare. Application: It is important to consider the impact of LED technology on visual performance to enhance road safety in critical glare situations during night driving.]]></description>
      <pubDate>Fri, 13 Jun 2025 09:13:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2549037</guid>
    </item>
    <item>
      <title>Research into the Design of Tunnel Photovoltaic Sunshades Based on Visual Efficacy Experiments</title>
      <link>https://trid.trb.org/View/2556955</link>
      <description><![CDATA[Aiming at the problem of “black hole effect” at tunnel entrances, this study proposes a widely applicable design method for photovoltaic sunshade, which not only verifies the theoretical effect of the design scheme through a combination of simulation and experiment, but also provides sufficient theoretical basis for the design selection of sunshades. This study is divided into the following key stages. First, analyzing the shortcomings of existing studies and clarifying the importance of driver reaction time as a safety indicator. Second, constructing an evaluation framework integrating economy, safety, and visual comfort to ensure the comprehensiveness and scientificity of the evaluation of design options. Then, proposing a series of pre-selected sunshade design options and simulating the illumination changes of each viewpoint in different scenarios by means of the visual efficacy experiments. Subsequently, two-factor ANOVA and simple effect analysis are used to study in depth the mechanism of the influence of the combination of sunshade length and light transmission rate on drivers’ reaction times, and to reveal the role of the key design parameters. Finally, the combined weight and technique for order of preference by similarity to ideal solution (TOPSIS) method is used for comprehensive evaluation and to determine the optimal design scheme. Taking Rongwu Expressway Yingerling Tunnel in China as an example, according to the research and analysis, the recommended design scheme of photovoltaic sunshade is as follows: the total length is 80?m, the combination of light transmittance is 0.8-0.6-0.4-0.2-0.1, and the length of each section is 16?m.]]></description>
      <pubDate>Tue, 27 May 2025 16:31:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2556955</guid>
    </item>
    <item>
      <title>Lighting Studies at Texas City Wye</title>
      <link>https://trid.trb.org/View/2543299</link>
      <description><![CDATA[The Texas City Interchange on Route 3 from Houston to Galveston was the subject of lighting research. The intersection was experimentally lighted with several arrangements of overhead luminaires so that many combinations of spacing and mounting heights could be employed. The visual effects of various combinations of lights from two of the approach directions are discussed in this publication.]]></description>
      <pubDate>Mon, 12 May 2025 12:02:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2543299</guid>
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