|   | 
Details
   web
Records
Author Kersavage, K.; Skinner, N.P.; Bullough, J.D.; Garvey, P.M.; Donnell, E.T.; Rea, M.S.
Title Investigation of flashing and intensity characteristics for vehicle-mounted warning beacons Type Journal Article
Year 2018 Publication Accident Analysis & Prevention Abbreviated Journal Accident Analysis & Prevention
Volume 119 Issue Pages 23-28
Keywords Security; Public Safety; Lighting
Abstract (up) Reducing the potential for crashes involving front line service workers and passing vehicles is important for increasing worker safety in work zones and similar locations. Flashing yellow warning beacons are often used to protect, delineate, and provide visual information to drivers within and approaching work zones. A nighttime field study using simulated workers, with and without reflective vests, present outside trucks was conducted to evaluate the effects of different warning beacon intensities and flash frequencies. Interactions between intensity and flash frequency were also analyzed. This study determined that intensitiesof 25/2.5 cd and 150/15 cd (peak/trough intensity) provided the farthest detection distances of the simulated worker. Mean detection distances in response to a flash frequency of 1 Hz were not statistically different from those in response to 4 Hz flashing. Simulated workers wearing reflective vests were seen the farthest distances away from the trucks for all combinations of intensity and flash frequency.
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 0001-4575 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1950
Permanent link to this record
 

 
Author Hyari, K.H.; Khelifi, A.; Katkhuda, H.
Title Multiobjective Optimization of Roadway Lighting Projects Type Journal Article
Year 2016 Publication Journal of Transportation Engineering Abbreviated Journal J. Transp. Eng.
Volume Issue Pages 04016024
Keywords Lighting; multiobjective optimization; traffic safety; road safety; lighting design; uniformity; genetic algorithm
Abstract (up) Roadway lighting systems play a major role in maintaining nighttime traffic safety as they reduce both the number and severity of nighttime traffic accidents. While the design of roadway lighting systems involves multiple objectives, past studies have focused on optimizing only one of the multiple objectives that should be considered. This paper presents a multiobjective optimization model for roadway lighting projects that simultaneously optimizes four design objectives. The incorporated objectives are (1) maximizing the average lighting level on the road surface; (2) maximizing the lighting uniformity along the roadway; (3) minimizing the glare to road users produced by the lighting system; and (4) minimizing the cost of operating the lighting system. The model is designed and developed as a multiobjective genetic algorithm to help decision-makers in their endeavor to provide efficient roadway lighting systems that strike a balance between the four conflicting objectives. The present model considers the following six design variables: type of lighting fixture, mounting height, spacing, fixture offset, fixture’s inclination, and fixture’s rotation angle. An application example is analyzed in this paper to clarify the use of the model and display its significant features in producing better lighting arrangements for roadways.
Address Dept. of Civil Engineering, Hashemite Univ., P.O. Box 150459, Zarqa 13115, Jordan; hyari(at)hu.edu.jo
Corporate Author Thesis
Publisher ASCE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0733-947X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1405
Permanent link to this record
 

 
Author Monsere, C.M.; Fischer, E.L.
Title Safety effects of reducing freeway illumination for energy conservation Type Journal Article
Year 2008 Publication Accident; Analysis and Prevention Abbreviated Journal Accid Anal Prev
Volume 40 Issue 5 Pages 1773-1780
Keywords Lighting; Accidents, Traffic/*statistics & numerical data; *Automobile Driving; *Conservation of Energy Resources; Environment Design; Humans; *Lighting; Models, Statistical; Oregon; Safety; Wounds and Injuries/epidemiology
Abstract (up) The addition of illumination where none was present is generally believed to have a positive effect on motor vehicle safety; reducing the frequency, as well as the severity of crashes. The operational cost of illumination, however, can make it a candidate for conservation during periods of high energy costs. In response to a forecasted energy shortage, the Oregon Department of Transportation selectively reduced illumination on interstate highways as part of an energy-saving effort. The reductions occurred at 44 interchanges and along 5.5 miles of interstate highway. This paper presents the results of a crash-based analysis of the changes in safety performance using an empirical-Bayes observational methodology. The study found an increase in reported crashes where the lineal lighting was reduced both in total crashes (28.95%, P=0.05) and injury night crashes (39.21%, P=0.07). Where full interchange lighting was reduced to partial lighting, a 2.46% increase (P=0.007) in total night crashes was observed. Injury night crashes, however, decreased by 12.16% (P<0.001) though day injury crashes also decreased at these locations. Unexpectedly, for interchanges where illumination was reduced from partial plus to partial, a 35.24% decrease (P<0.001) in total crashes and 39.98 (P<0.001) decrease in injury night crashes was found, though again, day crashes also decreased.
Address Department of Civil & Environmental Engineering, Portland State University, P.O. Box 751, Portland, OR 97207-0751, USA. monsere@pdx.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-4575 ISBN Medium
Area Expedition Conference
Notes PMID:18760107 Approved no
Call Number LoNNe @ kagoburian @ Serial 643
Permanent link to this record
 

 
Author Sullivan, J.M.; Flannagan, M.J.
Title Determining the potential safety benefit of improved lighting in three pedestrian crash scenarios Type Journal Article
Year 2007 Publication Accident; Analysis and Prevention Abbreviated Journal Accid Anal Prev
Volume 39 Issue 3 Pages 638-647
Keywords Lighting; Accidents, Traffic/*prevention & control/statistics & numerical data; Automobile Driving/*psychology; Darkness/*adverse effects; *Environment Design; Humans; Lighting/*standards; Prevalence; Risk; *Safety; Time; *Visual Perception; *Walking
Abstract (up) The influence of light level was determined for three pedestrian crash scenarios associated with three adaptive headlighting solutions-curve lighting, motorway lighting, and cornering light. These results were coupled to corresponding prevalence data for each scenario to derive measures of annual lifesaving potential. For each scenario, the risk associated with light level was determined using daylight saving time (DST) transitions to produce a dark/light interval risk ratio; prevalence was determined using the corresponding annual crash rate in darkness for each scenario. For curve lighting, pedestrian crashes on curved roadways were examined; for motorway lighting, crashes associated with high speed roadways were examined; and for cornering light, crashes involving turning vehicles at intersections were examined. In the curve analysis, lower dark/light crash ratios were observed for curved sections of roadway compared to straight roads. In the motorway analysis, posted speed limit was the dominant predictor of this ratio for the fatal crash dataset; road function class was the dominant predictor of the ratio for the fatal/nonfatal dataset. Finally, in the intersection crash analysis, the dark/light ratio for turning vehicles was lower than for nonturning vehicles; and the ratio at intersections was lower than at non-intersections. Relative safety need was determined by combining the dark/light ratio with prevalence data to produce an idealized measure of lifesaving potential. While all three scenarios suggested a potential for safety improvement, scenarios related to high speed roadway environments showed the greatest potential.
Address The University of Michigan Transportation Research Institute, 2901 Baxter Road, Ann Arbor, MI 48109-2150, USA. jsully@umich.edu <jsully@umich.edu>
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0001-4575 ISBN Medium
Area Expedition Conference
Notes PMID:17126278 Approved no
Call Number LoNNe @ kagoburian @ Serial 648
Permanent link to this record
 

 
Author Clanton, N.; Gibbons, R.; Garcia, J.; Barber, M.
Title Seattle LED Adaptive Lighting Study Type Report
Year 2014 Publication Northwest Energy Efficiency Alliance Abbreviated Journal NEEA
Volume Issue E14-286 Pages
Keywords Public Safety; Lighting; Planning; Vision
Abstract (up) The Northwest Energy Efficiency Alliance (NEEA) and the City of Seattle partnered to evaluate the future of solid state street lighting in the Pacific Northwest with a two-night demonstration in Seattle's Ballard neighborhood in March 2012. The study evaluates the effectiveness of LED streetlights on nighttime driver object detection visibility as function of light source spectral distribution (color temperature in degrees K) and light distribution. Clanton & Associates and VTTI also evaluated adaptive lighting (tuning of streetlights during periods of reduced vehicular and pedestrian activity) at three levels: one hundred percent of full light output, fifty percent of full light output, and twenty-five percent of full light output. The study, led by Clanton & Associates, Continuum Industries, and the VTTI, built upon previous visual performance studies conducted in Anchorage, Alaska; San Diego, California; and San Jose, California. The use of LED technology for city street lighting is becoming more widespread. While these lights are primarily touted for their energy efficiency, the combination of LEDs with advanced control technology, changes to lighting criteria, and a better understanding of human mesopic (low light level) visibility creates an enormous potential for energy savings and improved motorist and pedestrian visibility and safety. Data from these tests support the following statements: LED luminaires with a correlated color temperature of 4100K provide the highest detection distance, including statistically significantly better detection distance when compared to HPS luminaires of higher wattage. The non-uniformity of the lighting on the roadway surface provides a visibility enhancement and greater contrast for visibility. Contrast of objects, both positive and negative, is a better indicator of visibility than is average luminance level. Dimming the LED luminaires to fifty percent of IES RP-8 levels did not significantly reduce object detection distance in dry pavement conditions. Participants perceived dimming of sidewalks as less acceptable than dimming to the same level on the roadway. Asymmetric lighting did reduce glare and performed similarly to the symmetric lighting at the same color temperature (4100K).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language English 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 LoNNe @ kyba @ Serial 1763
Permanent link to this record