U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
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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
American Trade Initiatives, Inc. & Avalon Integrated Services, Inc. for the Federal Highway Administration U.S. Department of Transportation and The American Association of State Highway and Transportation Officials and The National Cooperative Highway Research Program (Panel 20-36) of the Transportation Research Board
Office of International Programs
FHWA/US DOT (HPIP)
400 Seventh Street, SW
Washington, DC 20590
Tel: 202-366-9636
Fax: 202-366-9626
international@fhwa.dot.gov
www.international.fhwa.dot.gov
Publication No. FHWA-PL-01-026
HPIP/6-00(5M)EW
June 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 the last page of this publication.
Website: www.international.fhwa.dot.gov Email: international@fhwa.dot.gov
The objective of the scanning tour was to review and document European procedures and practices in roadway geometric design and context-sensitive design |
A properly designed roadway takes into consideration mobility and safety while addressing natural and human environmental aspects. To achieve such a balance, tradeoffs among these factors are needed and are routinely performed either explicitly or implicitly. Recently, an emphasis has been placed on the existing flexibility in design guidelines and the use of creative design in addressing the site-specific project needs has been encouraged. This philosophy was coined in the United States as context-sensitive design (CSD) and represents an approach in which a balance is sought between safety and mobility needs within the community interests. Both the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) recognize the flexibility that exists in the current design guidelines, while acknowledging that the current focus on providing high levels of mobility may conflict with some interests of the community. The use of multi-disciplinary teams and public involvement at the appropriate stages of the project are also aspects that promote the application of CSD. Research and workshops have increased awareness of CSD issues within the highway community and encouraged a desire to improve and enhance established roadway design practices and address elements of community interest.
The CSD approach is a current practice in several European countries, which use these roadway geometric design concepts and tools to address mobility, safety, and community issues. From experience, European agencies may offer to U.S. practitioners valuable new insights and concepts on these issues and practices. Such concepts may be transferred or adapted to the U.S. environment to enhance the knowledge base regarding CSD and roadway geometric design.
The objective of the scanning tour was to review and document European procedures and practices in roadway geometric design and CSD. Sweden, Denmark, the Netherlands, England, and Germany were identified as countries that have innovative methods and procedures related to roadway geometric design and project development. The goal of the tour was to identify practices in the selected countries that, when implemented in the United States, would enhance current procedures and promote roadway designs that equally address mobility, safety, and community issues.
The International Scanning Tour for Roadway Geometric Design was jointly sponsored by FHWA and AASHTO, and the tour was coordinated by FHWA's Office of International Programs. The delegation included members representing FHWA, AASHTO, State departments of transportation (DOTs), the American Public Works Association (APWA), and academia. Individual team members brought their expertise in many roadway design and project developments areas, including CSD practices and procedures, application of geometric design principles for enhancing traffic safety and enforcing speed moderation, and consideration and integration of bicyclists and pedestrians in roadway design.
The U.S. delegation met with numerous representatives from transportation and highway ministries, research organizations, and consultants, who shared many interesting ideas and insights with the scanning team. Practices that the delegation found most significant are summarized below.
The countries visited have an underlying philosophy of a project planning process that aims to improve safety yet remains sensitive to the needs of the community. The focus is on improving the existing system by making better use of it. All countries visited generally have project development processes similar to those in the United States; however, they devote a longer period of time to the planning process and consider longer sections, typically entire corridors. The Europeans also place greater emphasis on integrating projects in communities by addressing the public's concerns about speed management and aesthetics, particularly in urban areas.
In Europe, public involvement also is an integral part of the project development process, although degrees and levels of involvement vary on the basis of project type and country. Some concepts and methods to involve the public could be transferable to the United States and could help streamline existing practices. To avoid potential conflicts and problems after a project has been fully developed, all governments that the team met with stressed public involvement at the earliest stage possible.
All the countries visited include environmental issues as an integral part of a project. It was interesting to find that several countries have copied or adapted the National Environmental Policy Act (NEPA) process, used in the United States, but have integrated it more efficiently within the project development process. The Dutch believe that recognition of environmental concerns is an everyday practice and that these concerns are addressed sufficiently through their normal design process. Currently, the Dutch are considering means by which the regulations and process can be streamlined to reduce project completion time. A general observation was that the highway agencies of the countries visited are more committed to addressing environmental issues than their U.S. counterparts; most of the issues presented were related to humans, including noise and concerns about historical preservation. The reliance on local governmental agencies to develop environmental impact studies (EIS) also was presented as a means of identifying problems and possible solutions more easily and at the local level.
Although representatives from each country used different terms to describe their design speed, all use a guiding speed for designing roadways that ties the various roadway elements together. Roadway design philosophies common to all countries were the reliance on the physical roadway design to "enforce" operating speeds and the development of a "consistent" or "self-explaining" appearance for each road category. These self-explaining, self-enforcing roads are designed for specific purposes or functions. Safety is addressed in an efficient way, by implementing an aesthetic approach to explain the road function and enforce speeds. An interesting observation was that European road users accept lower operating speeds than users in the United States. This attitude may be attributable, in part, to a self-enforcing roadway design.
All countries visited utilize guidelines for roadway design that are considered central to the design philosophy, and all have a design exception process through which to address departures from guidelines. This process is more frequently applied to non-motorways (or non-freeways). It was also apparent that all these countries have or are currently revising their design guidelines, which are now more focused on addressing road purposes and creating a uniform appearance for each road category. This experience has encouraged an understanding of the value of design flexibility and exceptions. Generally, the countries are shielded from legal liability regarding design defects. The exception is England, where litigation generated by departures from design guidelines is expanding; most of the litigation is settled out of court. In the countries visited, the guidelines issued by the national highway authorities are usually considered to be recommendations for any projects under the authority of local governmental agencies. This provides great flexibility in designing to meet local needs and conditions.
High speeds on rural roads is also a safety issue in the countries visited, and officials are focusing on attempts to control and reduce speeds. To achieve this objective, higher speeds are sacrificed to preserve safety. A common treatment on high-volume rural highways is 2+1 facilities, where the middle lane serves as a passing lane in which the right of way alternates. Use of this design instead of four-lane facilities has created gains in capacity and improvements in safety that may be transferable to the United States. Another approach for improving safety on these roads is the use of narrower lane widths, which requires drivers to slow down. This approach is implemented either by physically narrowing travelways or by visually decreasing the available roadway width. To further enforce the narrower roadway concept, clear zones are typically not provided, and some roadway objects are shielded by guardrails. It should be pointed out that such measures are only applied to non-motorways, where flexibility in design guidelines is permitted. On motorways, the guidelines are more rigid.
All countries are committed to reducing speeds through urban areas and are guided by the concept of integrating all modes and users in the same space. To achieve this objective, several traffic calming practices have been implemented in urban areas, including chicanes, islands, tables, cushions, humps, bumps, gates, landscaping, staggering, bollards, plantings, pavement textures and colors, and optical narrowing; i.e., narrowing the travelway with markings. For a successful implementation, an area-wide strategy is required, where a systemic, rather than localized, solution is sought. Thus the concept of traffic calming is enforced for the entire area, providing drivers with a clear and continuous message. Moreover, if roads are properly designed for the intended speed, drivers exceeding the speed are uncomfortable, but those traveling at the desired speed are not. Community acceptance is also very important for successful implementation. Most of these practices are transferable to the U.S. urban environment, although differences in land use, development, and transportation users must be recognized. In Europe, there appears to be greater public acceptance of reduced speed and mobility than in the United States.
All countries visited consider and address the needs of bicyclists and pedestrians, although there are two different philosophies regarding their levels of consideration. Sweden, Denmark, and the Netherlands place a high level of importance on addressing the needs of these users and provide separate facilities, as part of the network. Moreover, in those countries cycling and walking are heavily and systematically promoted as alternative transport modes. Germany and England, on the other hand, include these users in the planning process, but they are considered less important than in the other countries. One reason for the difference may be levels of demand, which are lower in Germany and England. All five countries place equal importance on the mobility needs of vehicles. One issue that all countries are struggling with is the integration of cyclists and pedestrians into roundabouts. Denmark and the Netherlands provide completely separate paths for these users, while other countries provide paths within the same travelway.
In the European countries visited, the general philosophy for roadway design and project development is to develop a transportation program and system that enhances community values and integrates roadways into communities and the environment. This philosophy permeates the project development process, safety improvements, roadway design concepts, geometric design guidelines, public involvement, and environmental commitments. This philosophy is the essence of the recent emphasis on promoting the CSD approach in the United States. A shift toward this philosophy is supported by FHWA and many State DOTs. Moreover, the roadway design philosophy of the Europeans is to develop roadways designed for specific purposes, implement an aesthetic approach to visually explain the concepts, and address safety in a way that considers all users. Finally, all countries have very high safety goals (ranging from zero fatalities to reductions of more than 40 percent for all crashes) that guide the design approach and philosophy. To achieve the goals, planners are willing to provide roadways that self-enforce speed reductions, potentially increase levels of congestion, and promote alternative modes of transportation. This approach contrasts with the U.S. design philosophy, in which wider roads are deemed safer, there is heavier reliance on signs to communicate the intended message, and there is a lower tolerance for congestion and speed reduction.
While all practices are not entirely new to all U.S. States, lessons could be learned from the forms and extent of the applications in Europe. To this end, the U.S. delegation identified a list of possible implementation strategies for enhancing existing project development and roadway geometric design practices in the United States.
While developing projects, State agencies may want to consider longer sections, to allow for a more systematic overview and definition of needs and deficiencies throughout the entire system. State and local agencies should, in urban areas, emphasize better integration of projects in communities by addressing the public's concerns about speed management and aesthetics. Public involvement, at the earliest possible stage of a project, is essential for a successful project, and this concept could be applied in the United States. Finally, the use of design workshops, in which all project alternatives are developed with public involvement, merits further examination, and could be transferable to U.S. practice.
The concept of 2+1 roads has been shown to simultaneously address safety issues when addressing capacity on two-lane roadways. The practice requires further investigation for possible implementation in the United States, to determine specific design elements and guidelines. Self-explaining, self-enforcing roads are facilities designed for a specific purpose or function, and they address safety in an efficient way, for all users, by implementing an aesthetic approach to explain road function and enforce speed. Reliance on the roadway design to transmit its operating speed is integral to the concept, which contrasts with the higher reliance on traffic signs to convey speeds in the United States.
Traffic calming is an effective means of controlling speeds through urban areas and deserves wider implementation in the United States. Even though there are a variety of speed reduction levels, all studies completed indicate that, indeed, such devices reduce speeds. Traffic calming is most effective if done on a neighborhood or area-wide basis, and not just at spot locations. While some of the measures have been tried in the United States, to a limited degree, more testing of various European traffic calming strategies is needed in U.S. cities.
Roundabouts are a very safe and efficient means of intersection control. Roundabouts with a single-lane approach are used widely and successfully in Europe, and they can easily accommodate peak flows of 2,500 vehicles per hour, without significant delays. Safety studies completed in most of the countries visited indicate that significant safety gains were achieved by implementing roundabouts instead of conventional intersections. Although roundabouts have been introduced in a few areas in the United States, this modern tool is still underutilized. State and local agencies should consider implementing and using roundabouts as an alternative to conventional intersection designs, as well as a means for improving traffic safety.
European countries place a significant emphasis on addressing the needs of pedestrians and bicyclists. In some countries, addressing the needs of these users is as important as improving vehicle mobility. Bicycle networks exist in all countries visited, and in some they are complete and rival the vehicle networks. In the United States, addressing mobility needs has been traditionally viewed as providing a roadway network where drivers can move as quickly and freely as they desire. This notion needs to be expanded to include all users, in order to address the safety needs of these vulnerable road users. State and local agencies are essential to promoting the use of these modes of transport and should focus on providing bicycle and pedestrian networks.
The development of transportation projects and systems that enhance community values while integrating roadways into the environment is an everyday practice that all countries follow. Consideration is given to the desires and needs of the community by inviting the appropriate stakeholders to participate in the development of a project, thus influencing some of the solutions so they are acceptable to the community. This approach is currently promoted by FHWA and AASHTO, and it should be continued in the future, until CSD becomes an integral part of the design process in the United States. Although not unheard of in the United States, design solutions that reduce motor vehicle speeds or reduce the space available to drivers may increase trip times and are not often viewed as appropriate. But wider, high-speed roads that address only the mobility of automobiles may not meet the needs of other users of the transportation system and often encourage higher travel speeds that contribute to the greater severity of crashes. CSD implies a flexible application of the established geometric criteria in designing roadways. The use of innovative design to address local problems and provide solutions within the context of the area is essential to applying the CSD concept. The self-explaining, self-enforcing road is an example of such innovative design, because it encourages lower operating speeds for automobiles while incorporating safety and mobility for all transportation modes.
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