Laboratory-Based Retroreflectivity Assessment of Raised Retroreflective Pavement Markers

2017 ◽  
Vol 2612 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Adam M. Pike
Keyword(s):  
Quantitative Evaluation ◽  
Visual Inspection ◽  
Observation Angle ◽  
Entrance Angle ◽  
Charge Coupled Device ◽  
Measurement Systems ◽  
Pavement Markings ◽  
Performance Requirements ◽  
Pavement Marking ◽  
Standard Marker

Pavement markings are often supplemented with raised retroreflective pavement markers (RRPMs) to provide increased visibility, especially in wet nighttime conditions. To provide adequate visibility, highway agencies need to replace their markings and markers before they reach inadequate levels of performance. Currently, there are no quantitative visibility performance requirements for in-service RRPMs. Most markers are replaced on the basis of visual inspection or predetermined replacement schedules. This paper presents an initial investigation into the impacts of different measurement systems and different geometries on the quantitative evaluation of the visibility of RRPMs. A key question was how the different measurement geometries affected the retroreflective performance of RRPMs. The research found that when the observation angle was held at 0.2° and the entrance angle increased, the coefficient of luminous intensity also increased. This finding was true for every color and brand of marker for the geometries tested. There was a notable drop in performance when the evaluation geometry was changed from pavement marker geometry to pavement marking geometry. When the photometric range was used, the pavement marking geometry resulted in data that were 7.8% of the values from the standard marker geometry. Charge-coupled device photometer measurements resulted in pavement marking geometry results that were on average 6.7% of the value of the RRPM geometry. These values being close indicated that the two measurement types were comparable and that the markers could consistently be evaluated at the two distinct geometries.

Minimum In-Service Retroreflectivity of Pavement Markings

2000 ◽  
Vol 1715 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Helmut T. Zwahlen ◽  
Thomas Schnell
Keyword(s):  
Field Experiments ◽  
Single Point ◽  
Luminance Contrast ◽  
Population Based ◽  
Time Of Day ◽  
Observation Angle ◽  
Contrast Threshold ◽  
Entrance Angle ◽  
Pavement Markings ◽  
Pavement Marking

Minimum in-service retroreflectivity values for pavement markings are presented based on visibility computations performed with the CARVE (Computer-Aided Road-Marking Visibility Evaluator) computer model. CARVE accurately computes all geometric and photometric relationships for each headlamp separately; applies the human visual luminance contrast threshold database from Blackwell (Part III, 1946) adjusted by a field factor function that has been obtained from a number of pavement marking visibility field experiments; and provides retroreflectivity values for the pavement markings for any selected single-point geometry (e.g., ASTM 30-m geometry, observation angle = 1.05°, entrance angle = 88.7°). Based on the CARVE computation results, a set of in-service pavement marking retroreflectivity values are derived for fully marked, dark, straight, and dry roads using paint-and-beads pavement markings. The derived minimum retroreflectivity values for fully marked roads without raised pavement markers (RPMs) are highly speed dependent, because the computations are based on a constant minimum preview time of 3.65 s (3.0 s true preview and 0.65 s for eye-fixation duration). A separate set of minimum retroreflectivity values, based on a constant preview time of 2.0 s, is provided for fully marked roads with RPMs in good working order. It was found that the minimum retroreflectivity requirements for pavement markings could be substantially relaxed if RPMs (in good photometric working condition) were used. The proposed minimum retroreflectivity values are based on a 62-year-old driver (about the 85th percentile of the licensed driver population, about the 95th per-centile of the nighttime driver population based on trip frequency data as a function of the time of day).

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.

Development and Implementation of a Pavement Marking Management System in Florida

2018 ◽  
Vol 2672 (12) ◽  
pp. 209-219
Author(s):  
Bouzid Choubane ◽  
Joshua Sevearance ◽  
Charles Holzschuher ◽  
James Fletcher ◽  
Chieh (Ross) Wang
Keyword(s):  
Management System ◽  
Handheld Devices ◽  
Department Of Transportation ◽  
Pavement Markings ◽  
Lighting Conditions ◽  
Florida Department ◽  
Roadway Safety ◽  
Application Techniques ◽  
Effective Use ◽  
Pavement Marking

The visibility of pavement markings is an important aspect of a safe transportation system as the markings convey vital roadway warnings and guidance information to the traveling public. Therefore, it is beneficial to maintain acceptable visibility levels of markings on pavements under all weather and lighting conditions. To ensure the intended in-service visibility level is adequately maintained, the reflectivity must be monitored and quantified accordingly. Historically, visibility or retroreflectivity of in-service pavement markings has been measured with handheld devices and visual inspections. However, visual surveys are considered subjective and the handheld measurements are tedious and potentially hazardous. Consequently, the Florida Department of Transportation (FDOT) has focused on the use of a non-contact technology capable of assessing pavement markings continuously at highway speeds with improved safety and efficiency. The use of mobile technology for measuring reflectivity has allowed FDOT to develop and, subsequently, implement a Pavement Marking Management System (PMMS) to improve the safety and nighttime visibility of its roadways. Implementation of such a system provides an efficient and less subjective methodology to identify conditions that are detrimental to roadway safety, and strategize mitigating solutions including the selection of appropriate materials and application techniques. The system will ultimately result in an effective use of state funds while ensuring the safety of the traveling public. This paper presents a description of the Florida Pavement Markings Management System and its subsequent implementation including FDOT’s effort to ensure the quality, consistency, repeatability, and accessibility of statewide pavement marking retroreflectivity data.

scholarly journals Rigorous Co-Registration of KOMPSAT-3 Multispectral and Panchromatic Images for Pan-Sharpening Image Fusion

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2100
Author(s):  
Changno Lee ◽  
Jaehong Oh
Keyword(s):  
Image Fusion ◽  
Visual Inspection ◽  
Camera System ◽  
Charge Coupled Device ◽  
Physical Sensor ◽  
The Difference ◽  
Terrain Elevation ◽  
Imaging Sensor ◽  
Sensor Modeling ◽  
Geometric Discrepancy

KOMPSAT-3, a Korean earth observing satellite, provides the panchromatic (PAN) band and four multispectral (MS) bands. They can be fused to obtain a pan-sharpened image of higher resolution in both the spectral and spatial domain, which is more informative and interpretative for visual inspection. In KOMPSAT-3 Advanced Earth Imaging Sensor System (AEISS) uni-focal camera system, the precise sensor alignment is a prerequisite for the fusion of MS and PAN images because MS and PAN Charge-Coupled Device (CCD) sensors are installed with certain offsets. In addition, exterior effects associated with the ephemeris and terrain elevation lead to the geometric discrepancy between MS and PAN images. Therefore, we propose a rigorous co-registration of KOMPSAT-3 MS and PAN images based on physical sensor modeling. We evaluated the impacts of CCD line offsets, ephemeris, and terrain elevation on the difference in image coordinates. The analysis enables precise co-registration modeling between MS and PAN images. An experiment with KOMPSAT-3 images produced negligible geometric discrepancy between MS and PAN images.

Closed-Course Human Factors Evaluation of Marking and Marker Visibility

2019 ◽  
Vol 2673 (10) ◽  
pp. 840-849
Author(s):  
Timothy P. Barrette ◽  
Adam M. Pike
Keyword(s):  
Pavement Markings ◽  
Passenger Seat ◽  
Driver Performance ◽  
Dry Conditions ◽  
The Right ◽  
Pavement Marking ◽  
Study Participants ◽  
Treatment Adequacy ◽  
The Relationship ◽  
Light Precipitation

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.

The Carbon Fibre Structure for the Extreme Ultraviolet Imaging Spectrometer on the Solar-B Satellite

2005 ◽  
Vol 219 (3) ◽  
pp. 177-186
Author(s):  
C Castelli ◽  
R Hagood ◽  
H Mapson-Menard ◽  
B Winter
Keyword(s):  
Carbon Fibre ◽  
Extreme Ultraviolet ◽  
Thermal Design ◽  
Imaging Spectrometer ◽  
Charge Coupled Device ◽  
Performance Requirements ◽  
Reinforced Plastic ◽  
Final Design ◽  
Carbon Fibre Reinforced Plastic

The Extreme Ultraviolet Imaging Spectrometer (EIS) is a core instrument on the Japanese Solar-B mission and is due for launch in the summer of 2006. EIS is a 3.2 m long telescope employing grating optics and a pair of charge coupled device imaging cameras working in the extreme ultraviolet (EUV) region in two separate wavelength bands between 170-210 and 240-290 Å. To house all the telescope subsystems, a novel carbon fibre reinforced plastic structure was developed in collaboration with McLaren Composites Limited (UK) to meet a set of the demanding performance requirements in terms of dimensional stability, rigidity, and structural cleanliness as well as being able to survive the harsh launch environment of the Japanese M-V rocket. The final design was based on a honeycomb panel structure using stiff carbon fibre laminates. This case study describes some of the design challenges that were overcome for this project to produce the engineering, mechanical, and thermal models. Particular attention is given to the cleanliness control strategy to preserve the EUV optical throughput, the method of attachment to the spacecraft, and of optical subsystems as well as the instrument thermal design.

Night Time Recognition of Reflectorized Warning Plates as a Function of Shape and Target brightness

1988 ◽  
Vol 32 (15) ◽  
pp. 971-975 ◽  
Author(s):  
Helmut T. Zwahlen ◽  
Daryle Jean Gardner-Bonneau ◽  
Charles C. Adams ◽  
Michael E. Miller
Keyword(s):  
Target Recognition ◽  
Observation Angle ◽  
Night Time ◽  
Experimental Conditions ◽  
Entrance Angle ◽  
Equal Area ◽  
Heading Angle ◽  
Different Shapes ◽  
The Right ◽  
Airport Runway

Two independent studies, each employing 12 subjects sitting in a stationary car on an unused airport runway with low beams on, were conducted to determine the distance at which a shape coded, reflectorized warning plate can be recognized at night as a function of target brightness. Recognition distances were recorded for a balanced combination of 15 experimental conditions consisting of 3 different specific intensity levels of target brightness (high 1080 cd/fc/sq ft at .2 degrees observation angle and −4 degrees entrance angle; medium 305 cd/fc/sq ft and low 105 cd/fc/sq ft) and 5 different shapes of equal area (18 square inches) targets (rectangle, circle, square, triangle, octagon). Study 1 used a car heading angle of 10 degrees to the right while Study 2 used a car heading angle of −3 degrees to the left. Results of these studies indicated that increasing target brightness had either no effect or only a small effect on target recognition distance, and the triangle (the object with the longest sides) was recognized at the largest distance and with the fewest errors. Targets were also recognized further away at the 10 degree car heading angle (less beam illumination) than at the −3 degree car heading angle (near maximum beam illumination). Implications of these results for the design and display of shape coded reflectorized warning plates in both traffic and industrial settings are discussed.

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.

Repeatability and Reproducibility of Mobile Retroreflectivity Units for Measurement of Pavement Markings

2013 ◽  
Vol 2337 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Bouzid Choubane ◽  
Joshua Sevearance ◽  
Hyung Suk Lee ◽  
Patrick Upshaw ◽  
James Fletcher
Keyword(s):  
Handheld Devices ◽  
Department Of Transportation ◽  
Safety Hazards ◽  
Handheld Device ◽  
Pavement Markings ◽  
Florida Department ◽  
Reference Device ◽  
Efficient Alternative ◽  
Repeatability And Reproducibility ◽  
Pavement Marking

The Florida Department of Transportation has historically used a combination of handheld devices and visual surveys to evaluate the retroreflectivity of pavement markings. However, visual surveys have the inherent limitations of operator bias, while the use of a handheld device is slow and labor intensive and presents safety hazards. Many highway agencies have recognized that a mobile retroreflectivity unit (MRU) may be a safer and more efficient alternative to the handheld retroreflectometers. Because the measurement process relies on the operator-driven instrument, a level of uncertainty is always a concern in evaluating pavement markings with the MRU. This research was aimed at assessing the precision and bias of the MRU while using the handheld retroreflectometer as a reference device. Ten 1.0-mi-long field sites were selected to include various pavement surface types and pavement marking materials (paints and thermoplastics). The results indicated that, when compared with the handheld retroreflectometers, the MRU demonstrated no statistical differences or bias at a 95% confidence level for the retroreflectivity values ranging between 200 and 800 mcd/m2/lux. In addition, it was determined that the retroreflectivity values from two properly conducted tests using a single MRU on the same pavement marking should not differ by more than 7.8%, and when different MRUs were used on the same pavement marking, the retroreflectivity values should not differ by more than 13.3%. This paper presents a description of the testing program, the data collection effort, and the subsequent analyses and findings.

Sign in / Sign up

Export Citation Format

Share Document