U.S. Department of Transportation
Federal Highway Administration
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The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official policy of the Department of Transportation.
The metric units reported are those used in common practice by the persons interviewed. They have not been converted to pure SI units because in some cases, the level of precision implied would have been changed.
The United States Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear herein only because they are considered essential to the document.
The publication of this document was sponsored by the U.S. Federal Highway Administration under contract number DTFH61-99-C00005. awarded to American Trade Initiatives, Inc. Any opinions, options, findings, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect those of the U.S. Government, the authors' parent institutions, or American Trade Initiatives, Inc.
This report does not constitute a standard, specification, or regulation.
Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
and
September 2001
The FHWA's international programs focus on meeting the growing demands of its partners at the Federal, State, and local levels for access to information on state-ofthe-art technology and the best practices used worldwide. While the FHWA is considered a world leader in highway transportation, the domestic highway community is very interested in the advanced technologies being developed by other countries, as well as innovative organizational and financing techniques used by the FHWA's international counterparts.
The International Technology Scanning Program accesses and evaluates foreign technologies and innovations that could significantly benefit U.S. highway transportation systems. Access to foreign innovations is strengthened by U.S. participation in the technical committees of international highway organizations and through bilateral technical exchange agreements with selected nations. The program has undertaken cooperatives with the American Association of State Highway Transportation Officials and its Select Committee on International Activities, and the Transportation Research Board's National Highway Research Cooperative Program (Panel 20-36), the private sector, and academia.
Priority topic areas are jointly determined by the FHWA and its partners. Teams of specialists in the specific areas of expertise being investigated are formed and sent to countries where significant advances and innovations have been made in technology, management practices, organizational structure, program delivery, and financing. Teams usually include Federal and State highway officials, private sector and industry association representatives, as well as members of the academic community.
The FHWA has organized more than 40 of these reviews and disseminated results nationwide. Topics have encompassed pavements, bridge construction and maintenance, contracting, intermodal transport, organizational management, winter road maintenance, safety, intelligent transportation systems, planning, and policy. Findings are recommended for follow-up with further research and pilot or demonstration projects to verify adaptability to the United States. Information about the scan findings and results of pilot programs are then disseminated nationally to State and local highway transportation officials and the private sector for implementation.
This program has resulted in significant improvements and savings in road program technologies and practices throughout the United States, particularly in the areas of structures, pavements, safety, and winter road maintenance. Joint research and technology-sharing projects have also been launched with international counterparts, further conserving resources and advancing the state of the art.
For a complete list of International Technology Scanning topics, and to order free copies of the reports, please see list on the facing page.
Website: www.international.fhwa.dot.gov Email: international@fhwa.dot.gov
The volume of vehicle traffic is increasing worldwide, and roadway lighting can be an effective tool to help provide efficient and safe traffic movement. The U.S. transportation community is interested in identifying cutting-edge research and technologies in highway and roadway lighting systems. Specific interests include tunnel illumination, sign lighting, and visibility metrics that are used in the design of roadway lighting systems.
The American Association of State Highway and Transportation Officials (AASHTO) is in the process of updating its Informational Guide for Roadway Lighting and recognizes the need to gather information from transportation ministries and lighting professionals outside the United States. The information gathered will provide a basis to update the Guide and will provide a better tool for State and local authorities that design, install, operate, and maintain public lighting systems.
The study was co-sponsored by the U.S. Federal Highway Administration (FHWA), an agency of the U.S. Department of Transportation, and by AASHTO. The purpose of the study was to gather information related to current roadway lighting practices and innovative solutions used by other countries.
The team members brought a variety of professional perspectives to the study. Representation included the States of Alabama, Pennsylvania, Texas, and Wisconsin; the FHWA; and the Illuminating Engineering Society of North America (IESNA).
The lighting study was conducted during the first 16 days of April 2000, with meetings held in Finland, Switzerland, France, Belgium, and the Netherlands. The delegation met with professionals in the field of roadway lighting to observe and evaluate the European experience in a number of areas of specific interest, including small target visibility (STV) and luminance design techniques.
Information was collected on the following 10 primary areas of interest, which form the main sections of this report:
Based on its observations, the panel developed specific recommendations for the roadway lighting and safety communities in the United States. The recommendations appear below, in descending order of priority.
The team members found that none of the countries visited use visibility techniques in design. Visibility research with three-dimensional targets is, however, being conducted in France and Belgium.
European research suggests that the visibility concept may provide a more complete approach to lighting design, although more experience is needed. The panel recommends experimentation and research on active roadways.
In the Netherlands, highway engineers have installed a dynamic roadway lighting system that can be operated at three levels, depending on the amount of traffic and weather conditions. The high level is 2 cd/m2, the normal level is 1 cd/m2, and the low level is 0.2 cd/m2. The crash rate for the 0.2-cd/m2 system, when operated at low traffic volumes, was acceptable. From these results it was determined that new systems will be installed to operate at 1 cd/m2 and 0.2 cd/m2. A similar road is currently being installed in Finland.
The French are studying retroreflectivity and active luminous devices. Similarly, the acceptability of different types of guidance systems is being researched in the Netherlands.
As an approach to more dynamic management of roadway lighting, the panel recommends investigating the application of dimmable lighting systems, turning off lighting systems, and alternative guidance systems.
All of the countries use the luminance design method for roadways. Several countries noted that there are problems with the standard "R-tables." The initial luminance values measured in the field vary from the values predicted by the design calculations that used the standard R-tables.
It was stressed to the panel that, when doing field measurements, the roadway must be dry and the temperature must be above the dew point. It was also noted that better correlation between calculated and measured values is obtained when measurements are made in the summer.
The French are researching the photometric properties of road surfaces. The evolution of road surface technology and the use of bright and colored road surfaces necessitated the research. Examples of new road surfaces are "quiet" and "waterdraining" pavements and very thin asphaltic concretes and surface dressings. The French also are examining the possibility of using a virtual reflectometer for field measurements.
Pavement reflectance is an important element of lighting design. The panel recommends that more research, including field measurements, be conducted in order to overcome the acknowledged inadequacy of the R-tables for pavements.
A number of European cities have master lighting plans. The plans are based on providing safety, beautification, and security for goods and people. Urban lighting is viewed as a key component of city management.
The panel encourages the development of master lighting-design plans to improve the coordination of roadway and urban lighting in such matters as lighting levels and styles and themes for safety, security, and beautification.
Each of the countries visited has specific recommendations for roundabout lighting. All cited the importance of having roundabout light levels higher than the levels on approach streets.
The panel recommends that the European experience in roundabout lighting be synthesized and consolidated for U.S. application.
The Swiss have modified lighting techniques to provide vertical illuminance, which allows pedestrians in crosswalks to be seen in positive contrast. The result has been a lowering of fatalities by two-thirds. Other countries also cited the importance of vertical illumination in pedestrian areas to enhance easy identification.
The panel recommends the consideration of vertical illuminance as a design approach to improve safety in crosswalks and other pedestrian areas.
Energy-absorbing poles flatten upon impact, but do not break away. They are used mainly in Finland and may be useful in the United States, in areas where breakaway poles are not desirable.
The panel recommends investigating the use of energy-absorbing poles as an option for selected applications.
Throughout the trip, the team encountered many instances in which the Europeans gained knowledge and experience by conducting practical experiments on active roadways. This method permits more rapid implementation of new ideas.
The panel encourages more innovative experimentation on active roadways and test tracks.
The police in Zurich, Switzerland, presented an extensive accident report. The panel found it interesting that the police analyze the cause of automobile accidents in the Zurich area and make recommendations for lighting applications.
The panel recommends the development of reporting systems that consider the lighting conditions at crash scenes.
There is a potential to gather a great deal of information from European lighting documents. The panel recommends further evaluation of the European standards and guidance documents to determine applicability in the United States.
The European lighting equipment generally appeared to be of a high quality, and very few roadway lighting outages were observed. The lighting systems were generally relamped on a group basis, typically on a 3- to 5-year cycle. Maintenance of tunnel lighting systems is generally conducted on a shorter cycle that coincides with the cycle for washing. Necessary relamping is conducted at that time. It was stated that the tunnels on the loop, in Paris, are cleaned every month.
The panel recommends that, when possible, higher quality lighting materials be considered to benefit maintenance and durability for the life of the lighting systems. In addition, maintenance personnel should be thoroughly trained to ensure the integrity of lighting systems.
Several countries are beginning to eliminate sign lighting by using micro-prismatic sheeting material. France also is moving away from fixed sign lighting by using engineering-grade retroreflective material.
The panel recommends the use of micro-prismatic materials for unlighted overhead and left-shoulder mounted signs.
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