Computer-Based Modeling to Determine the Visibility and Minimum Retroreflectivity of Pavement Markings

2000 ◽  
Vol 1708 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Thomas Schnell ◽  
Helmut T. Zwahlen
Keyword(s):  
Search Algorithm ◽  
Service Level ◽  
Point Of View ◽  
Blowing Snow ◽  
Service Levels ◽  
Pavement Markings ◽  
Federal Highway ◽  
Visibility Distance ◽  
Computer Based ◽  
Pavement Marking

The Federal Highway Administration was mandated by the U.S. Congress to establish in-service levels of minimum pavement-marking retroreflectivity and commissioned research to determine the minimum in-service level from a driver’s point of view. Computer Aided Road Marking Visibility Evaluator (CARVE) was developed and refined to systematically investigate drivers’ visual needs in terms of nighttime pavement-marking visibility and to allow the formulation of minimum retroreflectivity recommendations. The components within CARVE and the methods, algorithms, and equations that are used to determine the visibility distance of a given pavement-marking treatment are presented and discussed. CARVE systematically manipulates the pavement-marking efficiency (ηPM) up and down using a bisecting-search algorithm until the desired minimum required preview distance for selected conditions is achieved. Future expansions of CARVE, or the development of models that supersede it, may require additional research to investigate the wet-weather visibility of pavement markings, the effects of combined treatments consisting of pavement markings and raised reflective markers, and the visibility in inclement weather such as fog and blowing snow.

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.

scholarly journals Wet Night Visibility of Pavement Markings

2005 ◽  
Vol 1911 (1) ◽  
pp. 113-122
Author(s):  
Ronald B. Gibbons ◽  
Carl Andersen ◽  
Jonathan Hankey
Keyword(s):  
Test Methods ◽  
Pavement Markings ◽  
Visibility Distance ◽  
Dry Conditions ◽  
Simulated Rain ◽  
The Subject ◽  
Time Required ◽  
Pavement Marking ◽  
High Degree ◽  
System Operating

Thirty-three participants, all 60 years of age and older, evaluated the visibility of six different pavement marking materials under a simulated rain system operating at 0.8 in. (20 mm) of rain per h at night. Evaluation consisted of counting the number of skip lines visible from both a sedan and truck tractor, under headlight illumination only. Participants also evaluated markings from the sedan under dry conditions at night. Visual observations were compared with measured retroreflectivity of pavement marking materials, measured luminance of pavement marking materials at 30 m, and calculated retroreflectivity at 30 m, on the basis of measured luminance and illuminance provided by vehicle headlights. Data showed a high degree of correlation between the visibility distance of a marking material and the log of both the measured retroreflectivity and the calculated retroreflectivity. A definitive level of retroreflectivity required to meet drivers’ needs in wet night conditions was not found in the investigation and is now the subject of further study. There was also a high degree of correlation between measured and calculated values of retroreflectivity under simulated rain and measurements with the use of two current ASTM test methods, E2176 and E2177. In a second experiment, six original participants evaluated the visibility of the pavement marking materials for a 10-min interval following cessation of simulated rain. Results of the second experiment indicated significant differences in the time required for the visual performance of a pavement marking material to recover from rain for paint and bead products versus that of other pavement marking materials under evaluation.

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.

scholarly journals AVAILABILITY ASSESSMENT SIMULATIONS FOR ALLOCATING HUMAN RESOURCES IN AIRSPACE CONTROL CENTERS

2013 ◽  
Vol 4 (1) ◽  
pp. 61-76
Author(s):  
Walter Nogueira Pizzo
Keyword(s):  
Human Resources ◽  
Simulation Model ◽  
Control Systems ◽  
Computer Systems ◽  
Service Level ◽  
Point Of View ◽  
Operations And Maintenance ◽  
Human Operators ◽  
Availability Assessment

Airspace control systems introduced automation into functions previously performed by human operators. This situation increased the dependence on the availability of computer systems, in which degraded operation events can reduce the service level at any controlled airspace. This paper presents a relationship between availability and allocation of human resources in these centers, where maintenance and operations personnel are occasionally asked to repair losses caused by automated functions. A simulation model for the Arena tool is presented, to access availability, and then the operational point of view is explored, focusing on the required availability scenarios. The results presented herein can help determine the size of operations and maintenance teams, considering the reliability and maintainability parameters of airspace control systems.

scholarly journals E-Tax Website Quality: An Evaluation Framework

2015 ◽  
Vol 16 ◽  
pp. 38-48
Author(s):  
Sadia Qadar ◽  
Amani Moazzam ◽  
Nighat Ansari
Keyword(s):  
Practical Implication ◽  
Service Level ◽  
Point Of View ◽  
Evaluation Framework ◽  
Website Quality ◽  
Critical Characteristics

The study aims to evaluate the e-tax portal of Pakistan on the basis of the opinion of its users. It identifies the critical characteristics of quality that significantly exist in the e-tax portal and the characteristics that need to be given attention by the administrators as they are not up to the mark and do not show their significant presence. The study also highlights the problems faced by the users followed by the suggestions given by them in order to improve the quality of e-tax portal. As far as the practical implication of the study is concerned, it will help the FBR authorities to get an idea about the quality of e-tax website from the point of view of e-tax users which will enable them to take certain measure to improve the quality of e-portal and consequently the service level.

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.

A Machine Learning-Based System for Predicting Service-Level Failures in Supply Chains

2021 ◽  
Author(s):  
Gabrielle Gauthier Melançon ◽  
Philippe Grangier ◽  
Eric Prescott-Gagnon ◽  
Emmanuel Sabourin ◽  
Louis-Martin Rousseau
Keyword(s):  
Machine Learning ◽  
Supply Chain ◽  
Service Level ◽  
Learning System ◽  
Safety Stock ◽  
Service Levels ◽  
Sources Of Uncertainty ◽  
Supply Chain Efficiency ◽  
Percentage Points ◽  
Different Sources

Despite advanced supply chain planning and execution systems, manufacturers and distributors tend to observe service levels below their targets, owing to different sources of uncertainty and risks. These risks, such as drastic changes in demand, machine failures, or systems not properly configured, can lead to planning or execution issues in the supply chain. It is too expensive to have planners continually track all situations at a granular level to ensure that no deviations or configuration problems occur. We present a machine learning system that predicts service-level failures a few weeks in advance and alerts the planners. The system includes a user interface that explains the alerts and helps to identify failure fixes. We conducted this research in cooperation with Michelin. Through experiments carried out over the course of four phases, we confirmed that machine learning can help predict service-level failures. In our last experiment, planners were able to use these predictions to make adjustments on tires for which failures were predicted, resulting in an improvement in the service level of 10 percentage points. Additionally, the system enabled planners to identify recurrent issues in their supply chain, such as safety-stock computation problems, impacting the overall supply chain efficiency. The proposed system showcases the importance of reducing the silos in supply chain management.

Basic Concepts of Mobile Radio Technologies

2009 ◽  
pp. 113-120
Author(s):  
Christian Kaspar ◽  
Florian Resatsch ◽  
Svenja Hagenhoff
Keyword(s):  
Business Models ◽  
Service Level ◽  
Mobile Commerce ◽  
Mobile Radio ◽  
Mobile Internet ◽  
Point Of View ◽  
Mobile Technologies ◽  
Mobile Service ◽  
Service Adoption ◽  
Available Technology

Mobile radio technologies have seen a rapid growth in recent years. Sales numbers and market penetration of mobile handsets have reached new heights worldwide. With almost two billion GSM users in June 2006, and 74.7 million users of third generation devices, there is a large basis for business and product concepts in mobile commerce (GSM Association, 2006). Penetration rates average 80%, even surpassing 100% in some European countries (NetSize, 2006). The technical development laid the foundation for an increasing number of mobile service users with high mobile Web penetrations. The highest is seen in Germany and Italy (34% for each), followed by France with 28%, while in the U.S., 19% account for mobile internet usage (ComScore, 2006). One of the largest growing services is mobile games, with 59.9 million downloaded in 2006 (Telephia, 2006). Compared to the overall availability of handsets, the continuing high complexity and dynamic of mobile technologies accounts for limited mobile service adoption rates and business models in data services. Therefore, particular aspects of mobile technologies as a basis of promising business concepts within mobile commerce are illustrated in the following on three different levels: First on the network level, whereas available technology alternatives for the generation of digital radio networks need to be considered; second, on the service level, in order to compare different transfer standards for the development of mobile information services; third, on the business level, in order to identify valuable application scenarios from the customer point of view.

The strategic design of port services based on a total landed cost approach

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rosa G. González-Ramírez ◽  
J. Rene Villalobos ◽  
Cesar Meneses
Keyword(s):  
Service Time ◽  
Public Information ◽  
Service Level ◽  
Competitive Position ◽  
Content Type ◽  
Service Levels ◽  
Strategic Design ◽  
Confidentiality Agreement ◽  
Traffic Volumes ◽  
High Level

PurposeThis paper explores the effect of port's service time, particularly the mean and variability, on shippers' total landed costs to determine the competitive position of the port and derive recommendations for the strategic design of port services.Design/methodology/approachThe competitive position of a port is estimated considering the service level offered to the end-users of the port such as port service time, its variability and its effect on the total landed costs observed by the port users. The proposed methodology is meant to help ports to determine the required service time levels to maintain or gain a competitive advantage against other ports, in terms of attracting common hinterland's customers.FindingsResults show the advantages of considering service levels factors to determine the competitive position of a port, and what are the minimum characteristics required to capture more traffic volumes, that can help port managers to take strategic design decisions to better position the port in the current fierce market.Research limitations/implicationsThe proposed methodology is illustrated by considering a case study, which is the Port of Guaymas in Mexico. Data was not directly collected by the port, but based on interviews with shippers and public information, a representative case is presented. Due to a confidentiality agreement with the Port, specific references for most of the data used to estimate the model's parameters are not provided. The analysis is intended to show the potential value of this mechanism and can be used for evaluating the competitive position, from a high-level perspective, of any port to determine potential hinterland by improving the service level of the port.Originality/valueThe existing literature on port choice and port competition has not previously considered the effect of port service levels under the perspective of total landed costs of the users, being this paper a contribution to fulfill this gap.

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