|   | 
Details
   web
Records
Author Tinus, R. W.
Title Effects of Extended Photoperiod on Southern Rocky Mountain Engelmann Spruce and Douglas-fir Type Journal Article
Year 1981 Publication (down) Tree Planters' Notes Abbreviated Journal
Volume 32 Issue 4 Pages
Keywords Plants
Abstract Four sources of Engelmann spruce and two of Douglas-fir were grown under eight different extended photoperiod regimes. Incandescent light 1 minute of every 15 at night at 270 lux was more effective than continuous incandescent at 1200 lux or intermittent fluorescent at 950 lux at preventing bud dormancy and maintaining continuous height growth.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ intern @ Serial 2368
Permanent link to this record
 

 
Author Barrette, T.P.; Pike, A.M.
Title Closed-Course Human Factors Evaluation of Marking and Marker Visibility Type Journal Article
Year 2019 Publication (down) Transportation Research Record: Journal of the Transportation Research Board Abbreviated Journal Transportation Research Record
Volume in press Issue Pages
Keywords Vision
Abstract Raised retroreflective pavement markers (RRPMs) are commonly used to provide nighttime delineation of roadways. Although RRPMs are visible during dry conditions, they provide their greatest benefit during wet-night conditions, when typical pavement markings become flooded and lose their retroreflectivite properties. Naturally, the retroreflectivity of RRPMs degrades over time as a result of traffic, ultraviolet light, precipitation, and roadway maintenance activities. Subsequently, it is necessary to examine the relationship between driver performance and the condition of the RRPMs. To assess visibility relative to RRPM condition, study participants rode in the passenger seat of a vehicle operated by a member of the research team, traveling at approximately 15 mph, for two laps around a closed course. Throughout each lap of the course, nine treatments consisting of RRPMs or preformed pavement marking tape of various retroreflectivity levels diverged from a center line to either the right or left. Participants indicated when they could tell which direction the treatment diverged, which was recorded using a GPS unit. A generalized linear model was estimated on a dataset constructed by pairing the observed distances from various treatments with demographic information about each participant. The analysis indicates the distance at which a particular treatment would be visible, which can then be converted to preview time to assess treatment adequacy for a variety of speeds. The RRPM treatments generally provided adequate preview time for older drivers based on the extant literature; however, the preformed pavement marking tape was less adequate at higher speeds and under overhead lighting.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0361-1981 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2499
Permanent link to this record
 

 
Author Bullough, J.D.
Title Discussion of “Closed-Course Human Factors Evaluation of Marking and Marker Visibility” by Barrette and Pike Type Journal Article
Year 2019 Publication (down) Transportation Research Record: Journal of the Transportation Research Board Abbreviated Journal Transportation Research Record
Volume 2673 Issue 10 Pages 850-851
Keywords Commentary; Vision
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0361-1981 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2774
Permanent link to this record
 

 
Author Barrette, T.P.; Pike, A.M.
Title Closed-Course Human Factors Evaluation of Marking and Marker Visibility Type Journal Article
Year 2019 Publication (down) Transportation Research Record: Journal of the Transportation Research Board Abbreviated Journal Transportation Research Record
Volume 2673 Issue 10 Pages 840-849
Keywords Vision
Abstract Raised retroreflective pavement markers (RRPMs) are commonly used to provide nighttime delineation of roadways. Although RRPMs are visible during dry conditions, they provide their greatest benefit during wet-night conditions, when typical pavement markings become flooded and lose their retroreflectivite properties. Naturally, the retroreflectivity of RRPMs degrades over time as a result of traffic, ultraviolet light, precipitation, and roadway maintenance activities. Subsequently, it is necessary to examine the relationship between driver performance and the condition of the RRPMs. To assess visibility relative to RRPM condition, study participants rode in the passenger seat of a vehicle operated by a member of the research team, traveling at approximately 15 mph, for two laps around a closed course. Throughout each lap of the course, nine treatments consisting of RRPMs or preformed pavement marking tape of various retroreflectivity levels diverged from a center line to either the right or left. Participants indicated when they could tell which direction the treatment diverged, which was recorded using a GPS unit. A generalized linear model was estimated on a dataset constructed by pairing the observed distances from various treatments with demographic information about each participant. The analysis indicates the distance at which a particular treatment would be visible, which can then be converted to preview time to assess treatment adequacy for a variety of speeds. The RRPM treatments generally provided adequate preview time for older drivers based on the extant literature; however, the preformed pavement marking tape was less adequate at higher speeds and under overhead lighting.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0361-1981 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2775
Permanent link to this record
 

 
Author Flannagan, M.J.; Sivak, M.; Traube, E.C.; Kojima, S.
Title Effects of Overall Low-Beam Intensity on Seeing Distance in the Presence of Glare Type Journal Article
Year 2000 Publication (down) Transportation Human Factors Abbreviated Journal Transportation Human Factors
Volume 2 Issue 4 Pages 313-330
Keywords Public Safety; Vision
Abstract Previous studies have demonstrated that current low-beam headlamps do not provide adequate seeing distance for safety. Could this situation be improved by providing more total light from low-beam headlamps, leaving the relative distribution of light unchanged? Although such a proposal is probably not the best practical solution, it is important to consider some of the visual consequences of a general increase in light to analyze the overall problem of low-beam headlighting.

In a nighttime field study we measured seeing distance in the presence of glare as a function of headlamp intensity, always varying the intensity of the seeing light and glare light by the same proportion. Increasing intensity by a factor of about 3.8 increased seeing distance by about 17% for both young and old drivers. This result is consistent with predictions from quantitative vision modeling using veiling luminance to represent the disabling effects of glare. We also collected subjective estimates of discomfort glare and found, as expected, that the higher intensities produced substantially more discomfort.

Our findings suggest that, if objective visual performance is the only criterion, there is no clear upper limit to how intense low-beam headlamps should be. However, there may be a level at which people simply will not tolerate the subjectively discomforting effects of glare, or at which glare indirectly affects objective performance through its effects on subjective comfort. Because subjective discomfort, rather than objective visual performance, may be the limiting consideration for setting maximum glare levels, more research should be done to understand the nature and consequences of discomfort glare, including possible effects of subjective comfort on objective visual behavior.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1093-9741 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2127
Permanent link to this record