Visibility of New Centerline and Edge Line Pavement Markings

1997 ◽  
Vol 1605 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Helmut T. Zwahlen ◽  
Thomas Schnell
Keyword(s):  
Ohio University ◽  
Detection Distance ◽  
Pavement Markings ◽  
Upper Limit ◽  
Distance Data ◽  
Left And Right ◽  
Pavement Marking ◽  
Main Effects ◽  
Road Marking

The objective of the presented two-part study was to provide nighttime pavement-marking visibility data obtained under automobile low-beam illumination conditions in the field for further calibration of the Ohio University pavement-marking visibility model CARVE (Computer Aided Road Marking Visibility Evaluator). A total of 10 subjects participated in Part 1 of the study. The goal of Part 1 was to determine the end-detection distance of finite-length, new, medium-retroreflectivity, yellow pavement marking tape centerlines without edge lines as a function of the centerline configuration (single dashed, single solid, and double solid) and width. The results of Part 1 confirm that an increase in the average end-detection distance of about 55 percent represents the approximate upper limit of what can be achieved by adding more retro-reflective area to a yellow centerline. Part 2 consisted of four main experiments involving 10 subjects each and two follow-up experiments involving a total of 10 subjects. The goal of Part 2 was to provide pavement-marking end-detection distance data for fully marked roads consisting of left and right white edge lines with either a yellow double solid or single dashed centerline. The main effects of width, retroreflectvity, and centerline configuration were found to be statistically significant. A fully marked road consisting of both edge lines and a centerline generally appears to provide end-detection distances that are on average about twice as long as the end-detection distances that can be achieved with a centerline alone, without edge lines.

Assessment of Durability of Wet Night Visible Pavement Markings

2013 ◽  
Vol 2337 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Ronald B. Gibbons ◽  
Brian Williams ◽  
Benjamin Cottrell
Keyword(s):  
Human Factors ◽  
Research Effort ◽  
Detection Distance ◽  
Separate Paper ◽  
Pavement Markings ◽  
Diminishing Returns ◽  
Pavement Marking ◽  
Relationship Of ◽  
The Relationship

This paper describes the visibility experiment conducted as part of a research effort to establish the durability of pavement markings in an on-road installation. Six marking technologies were installed on a portion of Route 460 in Blacksburg, Virginia. A human factors experiment in natural rain conditions was performed to establish the visibility needs of the driver. The retroreflectivity of the markings was measured at intervals of 2 to 5 months, with six measurements over the course of 23 months (these data are discussed in a separate paper). Previous research suggested that a minimum retroreflectivity of 150 mcd/m2/lx should be maintained to meet drivers' visibility needs. As part of this research, a human factors experiment was conducted to test the validity of this recommendation. The distance at which participants could detect the end of a pavement marking was measured as well as the retroreflectivity of the marking at those points. The relationship of detection distance and retroreflectivity found in this study suggests that as retroreflectivity increases beyond 150 mcd/m2/lx, there are diminishing returns on detection distance. This finding suggests that the recommended minimum is appropriate for providing increased visibility for drivers, while keeping retroreflectivity requirements at a reasonable level for marking manufacturers.

Visibility of Yellow Center Line Pavement Markings as a Function of line Configuration and Line Width

1996 ◽  
Vol 40 (18) ◽  
pp. 919-922 ◽  
Author(s):  
Helmut T. Zwahlen ◽  
Thomas Schnell
Keyword(s):  
Line Width ◽  
Finite Length ◽  
Fold Increase ◽  
Center Line ◽  
Detection Distance ◽  
Pavement Markings ◽  
Upper Limit ◽  
Line Configuration ◽  
Line Type

The end detection distance of finite length yellow center lines (tape, no edge lines included) was determined in the field at night under automobile low beam illumination as a function of the line configuration (single dashed, single solid, and double solid) and width (0.05m, 0.1m). Ten subjects were used in the study. The factor line type (configuration and width), and approach direction were statistically significant. A 16 fold increase in the retro-reflective area resulted in a near 100% average end detection distance increase in the westbound direction, and in a 65% average end detection distance increase in the eastbound direction (different backgrounds). The findings confirm that an about 65% to near 100% increase in the average end detection distance represents the approximate upper limit of what can be achieved by adding more retro-reflective area to a yellow center line. Increasing the material retroreflectivity and/or improving the material angularity might be much more effective to increase the detection distance.

Human Factors Assessment of Pavement Marking Retroreflectivity in Simulated Rain and Dry Conditions

2021 ◽  
pp. 036119812110111
Author(s):  
Timothy P. Barrette ◽  
Adam M. Pike
Keyword(s):  
Human Factors ◽  
Subjective Rating ◽  
Detection Distance ◽  
Pavement Markings ◽  
Dry Conditions ◽  
Simulated Rain ◽  
Pavement Marking ◽  
Over Time

Pavement marking retroreflectivity standards are typically developed with dry conditions in mind, however, driving at night during rainfall is seemingly one of the most challenging and stressful situations for a driver. Furthermore, existing research indicates continuous wet retroreflectivity is relatively weakly correlated with dry retroreflectivity and deteriorates differently over time, leading to the obvious conclusion that dry retroreflectivity standards alone are not enough to ensure that pavement markings meet the needs of drivers across the breadth of roadway conditions that may occur. Consequently, developing standards for minimum continuous wet retroreflectivity for new installations and for maintenance purposes represents an important area for research. This study aims to develop new installation and maintenance values for continuous wet retroreflectivity based on a multifaceted, closed-course study of detectability of pavement markings in simulated rain and dry conditions. A series of 20 pavement marking samples was evaluated in relation to detection distance and subjective rating. The results of the study indicated that pavement markings need to be maintained at a continuous wet retroreflectivity value of 50 mcd/m2/lux based on a participant pool that skewed older in age, but that likely represents something close to the 85th-percentile driver. Additional salient findings included observed wet retroreflectivity loss in the existing literature of approximately 7% per month, as well as the maximum preview time in simulated rain conditions being substantially lower than in dry conditions.

Visibility of New Dashed Yellow and White Center Stripes as Function of Material Retroreflectivity

1996 ◽  
Vol 1553 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Helmut T. Zwahlen ◽  
Thomas Schnell
Keyword(s):  
Finite Length ◽  
Environmental Concerns ◽  
Vehicle Speed ◽  
Detection Distance ◽  
Left Edge ◽  
Pavement Markings ◽  
Industry Standards ◽  
Visibility Distance ◽  
Continued Use ◽  
Pavement Marking

Economic and environmental concerns have raised questions about the continued use of yellow center lines on two-lane highways and yellow left-edge lines on divided highways or freeway entrance and exit ramps. The use of yellow pavement markings as a warning to indicate opposing traffic appears to be a concept that is compatible with certain human factors population stereotypes and accepted industry standards (yellow for caution), but it is unclear how well the general driver population understands the message conveyed by yellow pavement markings. Another question is how the visibility of yellow center lines or left-edge lines compares with the visibility of similar white pavement markings. The effects of color (white and yellow) and material retroreflectivity (low, medium, and high) on the end detection distance of finite-length center lines at night under automobile low-beam illumination were determined. Ten subjects were used in a field experiment (rural, automobile low-beam conditions) to obtain the end detection distances of finite-length center stripes of 0.1-m width. The data show that the end detection distances of new yellow dashed center stripes and new white dashed center stripes are about the same. The average end detection distance was 30 to 35 m for the low-retroreflectivity material and about 62 m for the high-retroreflectivity material (four- to fivefold retroreflectivity increase). It is tentatively concluded that the use of white center stripes most likely will not result in a significant increase in the end detection distance when compared with the use of similar yellow center stripes. It is also tentatively concluded that an increase in the retroreflectivity of the pavement marking materials will result in a significant and desirable increase of the visibility distance, but to provide a minimum preview time of 3.6 sec (at a vehicle speed of 90 km/hr), even higher-retroreflectivity materials than the ones used in this study will be required.

Nighttime Visibility and Retroreflectance of Pavement Markings in Dry, Wet, and Rainy Conditions

2003 ◽  
Vol 1824 (1) ◽  
pp. 144-155 ◽  
Author(s):  
Thomas Schnell ◽  
Fuat Aktan ◽  
Yi-Ching Lee
Keyword(s):  
Weather Condition ◽  
Weather Conditions ◽  
Test Method ◽  
Detection Distance ◽  
Test Track ◽  
Pavement Markings ◽  
Wet Condition ◽  
Simulated Rain ◽  
Pavement Marking ◽  
Measures Of Effectiveness

Research was conducted to determine the nighttime visibility of flat pavement-marking tape, patterned pavement-marking tape, and wetweather pavement-marking tape in dry, wet (just after rainfall), and simulated rain conditions (ongoing 1-in./h rainfall). The measures of effectiveness were the detection distances, the eye-fixation distributions, and the pavement-marking retroreflectance. The research was sponsored by FHWA. The experiment was conducted on a test track in Cottage Grove, Minnesota. This test track had a section at which 1-in./h rainfall could be simulated. Eleven women and seven men, ranging in age from 55 to 74 (average age 62.5), participated in this study. The participants drove the experiment vehicles along the pavement-marking treatments. The participants were to state the earliest point at which they could see the end of the pavement markings. The retroreflectance of each pavement-marking material was measured with three handheld retroreflectometers under the three weather conditions according to ASTM E-1710 (dry), ASTM E-2177 (wet recovery), and ASTM E-2176 (continuous wetting). The retroreflectance values were correlated to the detection distances to determine the ability of each ASTM test method to predict visibility performance under the corresponding weather condition. The wet-weather tape performed best for detection distance, followed by the patterned tape and the flat tape. The detection distances were longest in the dry condition, shorter in the wet condition, and shortest in the simulated rain condition.

scholarly journals Using ADAS to Future-Proof Roads—Comparison of Fog Line Detection from an In-Vehicle Camera and Mobile Retroreflectometer

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1737
Author(s):  
Ane Dalsnes Storsæter ◽  
Kelly Pitera ◽  
Edward McCormack
Keyword(s):  
Warning System ◽  
Management Systems ◽  
Warning Systems ◽  
Lane Departure Warning ◽  
Automated Driving ◽  
Pavement Markings ◽  
Lighting Conditions ◽  
Lane Marking ◽  
Lane Departure ◽  
Pavement Marking

Pavement markings are used to convey positioning information to both humans and automated driving systems. As automated driving is increasingly being adopted to support safety, it is important to understand how successfully sensor systems can interpret these markings. In this effort, an in-vehicle lane departure warning system was compared to data collected simultaneously from an externally mounted mobile retroreflectometer. The test, performed over 200 km of driving on three different routes in variable lighting conditions and road classes found that, depending on conditions, the retroreflectometer could predict whether the car’s lane departure systems would detect markings in 92% to 98% of cases. The test demonstrated that automated driving systems can be used to monitor the state of pavement markings and can provide input on how to design and maintain road infrastructure to support automated driving features. Since data about the condition of lane marking from multiple lane departure warning systems (crowd-sourced data) can provide input into the pavement marking management systems operated by many road owners, these findings also indicate that these automated driving sensors have an important role in enhancing the maintenance of pavement markings.

scholarly journals Developing Pavement Marking Management Systems: A Theoretical Model Framework Based on the Experiences of the US Transportation Agencies

2021 ◽  
Vol 6 (2) ◽  
pp. 18
Author(s):  
Alireza Sassani ◽  
Omar Smadi ◽  
Neal Hawkins
Keyword(s):  
Asset Management ◽  
Management Practices ◽  
Relevant Literature ◽  
Building Blocks ◽  
Management Systems ◽  
Model Framework ◽  
Pavement Markings ◽  
The Us ◽  
Pavement Marking ◽  
Transportation Agencies

Pavement markings are essential elements of transportation infrastructure with critical impacts on safety and mobility. They provide road users with the necessary information to adjust driving behavior or make calculated decisions about commuting. The visibility of pavement markings for drivers can be the boundary between a safe trip and a disastrous accident. Consequently, transportation agencies at the local or national levels allocate sizeable budgets to upkeep the pavement markings under their jurisdiction. Infrastructure asset management systems (IAMS) are often biased toward high-capital-cost assets such as pavements and bridges, not providing structured asset management (AM) plans for low-cost assets such as pavement markings. However, recent advances in transportation asset management (TAM) have promoted an integrated approach involving the pavement marking management system (PMMS). A PMMS brings all data items and processes under a comprehensive AM plan and enables managing pavement markings more efficiently. Pavement marking operations depend on location, conditions, and AM policies, highly diversifying the pavement marking management practices among agencies and making it difficult to create a holistic image of the system. Most of the available resources for pavement marking management focus on practices instead of strategies. Therefore, there is a lack of comprehensive guidelines and model frameworks for developing PMMS. This study utilizes the existing body of knowledge to build a guideline for developing and implementing PMMS. First, by adapting the core AM concepts to pavement marking management, a model framework for PMMS is created, and the building blocks and elements of the framework are introduced. Then, the caveats and practical points in PMMS implementation are discussed based on the US transportation agencies’ experiences and the relevant literature. This guideline is aspired to facilitate PMMS development for the agencies and pave the way for future pavement marking management tools and databases.

COMPARISON OF ARTIFICIAL INSEMINATION AND NATURAL MATING ON REPRODUCTIVE PERFORMANCE OF FIVE STRAINS OF SHEEP DURING THE ANESTROUS SEASON IN AN INTENSIVE SYSTEM

1979 ◽  
Vol 59 (4) ◽  
pp. 675-683 ◽  
Author(s):  
A. J. HACKETT ◽  
H. A. ROBERTSON ◽  
E. K. INSKEEP ◽  
J. N. B. SHRESTHA ◽  
M. S. WOLYNETZ
Keyword(s):  
Reproductive Performance ◽  
Artificial Insemination ◽  
Hormone Treatment ◽  
Corpora Lutea ◽  
Blood Samples ◽  
Natural Mating ◽  
Main Effects ◽  
Mating Method ◽  
Intensive System

Synchronized estrus and ovulation were induced during the anestrous season (April–May 1974) in 373 ewes of three synthetic (one sire and two dam) strains and two unselected (Suffolk and Finnish Landrace) purebred strains by treatment with 30 mg fluorogestone acetate (FGA) impregnated in polyurethane intravaginal sponges for 12 days. Following sponge removal each ewe received 500 IU pregnant mares’ serum gonadotrophin (PMSG) IM. Of these, 167 were bred by artificial insemination (AI) at 48 and 60 h post sponge removal with 0.2 ml raw unextended semen collected by electroejaculation (EE). Five days after AI, ewes were exposed to a follow up ram for 16 days for subsequent mating if a second estrus occurred. The remaining 206 were exposed to rams for a period of 22 days for natural mating. Blood samples were collected from 69 ewes, 9, 19 and 27 days post sponge removal and analyzed for progesterone to ascertain if corpora lutea were formed and whether the ewes recycled. The age of ram by mating method interaction significantly affected both fertility and fecundity mainly because some of the younger rams lacked libido and experience for natural mating. There were no significant differences in prolificacy due to any of the main effects tested. Among the 69 ewes examined for progesterone levels, 93% had formed corpora lutea after hormone treatment and 16% recycled. Only 16 of the 255 ewes that did not conceive to the synchronized estrus lambed to the subsequent estrus.

Effects of Ethnicity in Attitudes toward Writing

1993 ◽  
Vol 72 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Ruth E. Knudson
Keyword(s):  
School Districts ◽  
Significant Interaction ◽  
Hispanic Students ◽  
Asian Students ◽  
Older Students ◽  
Attitudes Toward Writing ◽  
Competing Hypotheses ◽  
Anglo American ◽  
Main Effects

The purpose of this study was to assess the effects of ethnicity (as culture) on attitudes toward writing of students in Grades 4 to 8. A 19-item survey was administered to 1798 students in Grades 4 to 8 in ten schools in three school districts. There was no significant effect of ethnicity on the Total score, but there were significant main effects for grade and for gender and a significant interaction only for ethnicity by grade. Follow-up of significant main effects using Scheffé tests indicated that older students have higher scores than younger ones, suggesting their attitudes are less positive and girls have lower scores than boys, indicating their attitudes are more positive. The interaction of ethnicity by grade points to a pattern of Anglo-American and Hispanic students having higher (less positive) scores at each grade. This pattern is similar for black and Asian students, but in Grade 7 black and Asian students have lower scores than those in Grade 6. Competing hypotheses to explain the main effects are discussed. Results of analyses of the three factors reported in the development of this instrument in addition to the analysis of the total score are also discussed.

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