U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: Date: May/June 2004|
Issue No: Vol. 67 No. 6
Date: May/June 2004
FHWA's international scanning program identifies world-class technologies for application on U.S. highways.
|During an international scan tour on geometric design, a delegation of U.S. transportation officials visited Denmark, where the team witnessed the use of traffic-calming elements, including islands, narrow lanes, and pavement textures like those shown here.|
For years, the United States has reached beyond its borders to expand transportation knowledge. One of the most visible elements of this outreach is the Federal Highway Administration's (FHWA) 12-year-old International Technology Scanning Program, more commonly known as the scan program. As of early 2004, the program has conducted 54 scans, resulting in a wealth of information and benefits to the motoring public in the United States.
Participants in the first international scan, sponsored by FHWA in 1991, visited five European countries to explore asphalt pavement technologies. Since then, FHWA—now in formal partnership with the American Association of State Highway and Transportation Officials (AASHTO)—has conducted scans on subjects ranging from geotechnology to pedestrian-crossing technologies and intermodal transportation facilities.
Each scan is a 2-week interaction between senior U.S. transportation officials and their counterparts in other countries. The scans stimulate the implementation of emerging technologies. "Literally hundreds of ideas and new technologies have been identified by scan team members and are taking root in FHWA, State departments of transportation [DOTs], cities and counties, private companies, and universities," says Commissioner Jim Byrnes of the Connecticut DOT and chair of the National Cooperative Highway Research Program's (NCHRP) Panel 2036, which provides AASHTO's share of the funding for the scan program.
Ed Rice, safety engineer with the Florida DOT, visited Sweden, Germany, Netherlands, and the United Kingdom while participating in a scan tour on highway safety. "Through a collaborative planning process involving the district and central offices, the Florida DOT is implementing a strategic highway safety plan that sets the framework for addressing safety in the department for the next 5 years," he says. "I never would have been so knowledgeable and motivated to take bold steps and a new direction in safety in Florida if I had not experienced the success stories in Europe."
Benefits of Scanning
Scans normally are conducted early in the innovation cycle, helping put the technology or policy in context by evaluating it in practice outside the U.S. environment. The actual implementation is accomplished when leaders in State and local transportation agencies, who may have only a peripheral knowledge of the scan program, put the new concepts and technologies into practice. The long-term benefits are tangible, manifesting themselves in practical applications within the United States and through savings of time, money, and effort afforded by new technology and innovations.
The benefits of the scan process can be grouped into four broad areas. The first is cost savings attributed directly to the application of technologies identified by scan teams. The second is filling the toolboxes of FHWA and State DOTs with ideas generated as a result of participating in the scans. Third is the creation of new programs and policies, or validation of current U.S. practices. The fourth broad area is the evolution of future benefits as the technology or policy continues to develop.
Individual scans cost about $200,000 on average, totaling less than $10 million since the inception of the program. This cost is relatively low for the significant benefits described in the final reports prepared at the end of each tour. FHWA and AASHTO also derive value from the continuous interaction between U.S. engineers and their foreign colleagues, the acceleration of experimentation and adaptation, and the official credibility and support that corroborates the implementation of new technologies.
The impact of the scan program on U.S. policy and technology has been dramatic, ranging from the use of stone matrix asphalt surfaces to key policies like design-build contracting. The following snapshots of these and other innovations help demonstrate the depth and breadth of the scan program's impact on the U.S. highway community—and the traveling public.
About the Office of International Programs
Through the Office of International Programs, FHWA has a long and distinguished history of worldwide cooperation in advancing transportation technology. The concept of working together internationally was codified in Section 506 of Title 23 of the United States Code, giving FHWA the authority to "engage in activities to inform the domestic highway community of technological innovations in foreign countries that could significantly improve highway transport in the United States, to promote U.S. highway transportation expertise, goods, and services in foreign countries, and to increase transfers of U.S. highway transportation technology to foreign countries."
Reports on previous scan tours are available through the Office of International Programs. For more information, visit http://international.fhwa.dot.gov, e-mail firstname.lastname@example.org, or call 202–366–0111.
Stone Matrix Asphalt
When a team of pavement experts visited Europe during the first scanning study in 1991, the technology that impressed them most was stone matrix asphalt (SMA). A strong, stone skeleton held together by rich asphalt cement, SMA is an innovative pavement mix used widely in Europe for its ability to withstand rutting on heavily traveled roads. After the scan, U.S. government and industry experts formed a technical working group to evaluate the asphalt mix and develop specifications for its use in the United States.
The group conducted national research, developed mix procedures, set standards, hosted conferences, and delivered training courses. Since scan members introduced SMA in the United States, about 9.07 million metric tons (10 million tons) of the material have been used on more than 250 projects in 25 States. Surfaces paved with the mix are projected to last up to 20 years with minimal maintenance, and SMA now is the premium asphalt pavement solution for U.S. roads subject to heavy loads and high traffic volumes.
Some of the main differences between SMA and hot-mix asphalt are that SMA is more difficult to construct and may require longer mixing times, higher mixing temperatures, and higher quality control at the plant and job sites. The cost can be 10 percent or more than routine asphalt mixes, however, SMA performance will usually exceed the performance of other asphalt surface mixes.
Larry Michael of the Maryland State Highway Administration has become a strong advocate of using the material on U.S. roads. Maryland has spread 3.6 million metric tons (4 million tons) of SMA on its highways, more than any other State. "It is without a doubt the most tenacious mix I have ever seen," Michael says. "If constructed correctly, it is almost impossible to make it rut, and it will outlast any other mix."
The National Center for Asphalt Technology calculated that SMA could increase the life of a pavement surface by 25 percent.
Another technology accelerated by an international scan was the implementation of soil nailing. The installation of closely spaced steel bars in an excavated slope as construction proceeds from the top down strengthens the slope and creates a soil mass stable enough to hold the ground behind it and keep it from collapsing.
Known as soil nailing, this process facilitates the construction of steeper walls in smaller areas, saving time, construction costs, and right-of-way procurement. More than 500 soil nail walls have been completed in the United States with an estimated $100 million savings in construction costs alone.
|This core sample shows the surface texture of stone matrix asphalt and the stone-on-stone contact for coarse aggregate particles.|
Accelerated Loading Facilities
Scanning studies yielded new ideas on testing pavements for strength and durability. As a result, nearly 20 States and universities now own and operate accelerated loading facilities for pavement testing, such as vehicle-truck wheel loads, variable wheel speeds, simulations of side-to-side vehicle movements, and temperature effects. These facilities enable engineers to experiment with new pavement mixes under controlled conditions, improving performance and lengthening the life of pavements, while saving time and money.
Researchers used the laboratory equipment to validate SuperpaveTM binders and mixtures to significantly reduce the number of sites necessary for field experiments. Estimated savings are $20 million, based on the building and monitoring of Long-Term Pavement Performance (LTPP) Program sites around the country.
Researchers at the FHWA Turner-Fairbank Highway Research Center and the Colorado DOT are the primary users of the accelerated laboratory equipment, but many private sector companies employ similar equipment.
|During a tour of bridge and embankment foundations in Sweden, a scan team visited this soil-nailing project in which workers were using self-drilling and grouting nails to stabilize a slope.|
The United States has a long history of pavement testing that precedes the scanning program, but Tim Aschenbrener at the Colorado DOT credits the overseas scans with increasing the role of equipment like wheel-tracking devices. The Colorado DOT, for example, uses a French rutting tester, which assesses the ability of hot-mix asphalt to withstand rutting, and a German wheel-tracking device, which evaluates asphalt's susceptibility to both rutting and moisture. Colorado uses the equipment to establish a benchmark for asphalt quality and test potential changes in mix specifications.
"There has been quite an improvement in our asphalt mixes based on our test results since we first obtained the equipment," Aschenbrener says.
Success using European equipment also has fostered development of similar equipment in the States. Several State DOTs now use an American-made asphalt pavement analyzer. "The popularity and implementation of this equipment have been accelerated thanks to what we learned from the Europeans about analyzing asphalt with wheel-tracking devices," Aschenbrener adds.
The low-bid process has been the norm for contracting in the United States since the early 1900s; however, in more than a dozen European scan tours, U.S. executives witnessed the dramatic impact that alternative contracting practices can have on quality and innovation. New techniques include design-build contracting, performance-based maintenance contracting, and warranties. Under FHWA's Special Experimental Project No. 14, more than 300 design-build projects were approved for 25 States under the Federal-Aid Highway Program alone, with many more built using State funds. The impact has been to expedite important projects and bring them into service years sooner.
Design-build contracting combines, rather than separates, responsibility for the design and the construction phases of a transportation project. This method allows the contractor maximum flexibility for innovation in selecting design, materials, and construction methods. With design-build procurement, the contracting agency identifies the end-result parameters and establishes the design criteria. The prospective bidders then develop design proposals that take maximum advantage of their construction abilities. The contracting agency rates the submitted proposals based on factors such as design quality, timeliness, management capability, and cost. These noncost factors may be considered along with price in determining the best value for the purpose of awarding the contract.
The design-build concept is the project delivery system of choice on more than 50 percent of construction projects in the European Union and on more than 70 percent in Japan. In the United States, the use of design-build contracting by private sector organizations has increased over the past 30 years in an array of commercial, institutional, and industrial applications. The Federal government and many State and local governments employ design-build contracting for a significant percentage of their building programs as well.
In an evaluation of design-build contracting, the New York State DOT summarized the benefits, which include faster delivery of the project, smaller numbers of staff required for project administration and management, and innovative design and construction techniques.
|One of two accelerated loading facilities at FHWA’s Turner-Fairbank Highway Research Center.|
The United States has 21,284 scour-critical bridges, that is, bridges that were evaluated and are considered to be in danger of collapsing if a major flood event were to occur at their sites. (A major flood event is typically one that has a 50- to 100year return period.) Of these bridges, 4,339 probably will require some type of countermeasure beyond simple monitoring. Assuming each bridge has three piers that need to be protected, a traditional countermeasure would involve installing 382.5 cubic meters (500 cubic yards) of rock riprap (rocks used to prevent erosion from water currents) per pier at $115 per cubic meter ($150 per cubic yard), with repair costs totaling no less than $358 million. But if the bridges are repaired using new techniques observed in Germany, New Zealand, and the United Kingdom—such as partially grouted riprap and geofabric sand containers—the United States could save 15 percent, or nearly $53 million.
According to Sterling Jones, a research hydraulic engineer at FHWA, partially grouted riprap improves the stability of rock riprap revetments (materials placed on an embankment to prevent erosion or water damage). Injecting a special grout essentially locks several pieces of stone together in a random fashion. Engineers in Germany have developed admixtures, grout mix designs, and application techniques for underwater use, as well as dry applications.
Sand containers, the other technique, are made from a nonwoven fabric that is resistant to puncture during construction. The fabric has an indefinite life if kept unexposed to sunlight. In Europe, the containers are used to underlay a layer of rock, and U.S. researchers are considering using them in lieu of rock to fill existing scour holes around bridge foundations. The geofabric containers may provide the mass necessary for stability in fast currents and would flex enough to adapt to the irregular shape of a scour hole.
Once an NCHRP study, Project 24-20 Prediction of Scour at Bridge Abutments, is completed in October 2005, U.S. engineers will be able to begin applying these new concepts.
|This machine (left) performs tests on pavement mixes to determine their sensitivity to moisture damage by measuring the amount of rutting. Owned by the Colorado DOT, this American-made model was inspired by wheel-tracking devices observed in Germany during a scan tour. Examples of pavement specimens that passed (lower left) and failed (lower right) the test. Photos: Colorado DOT.|
Roads and Weather
Three scans have focused on winter maintenance and operations. The first two were devoted solely to maintenance, while the third included intelligent transportation systems (ITS) technology and other aspects of winter operations.
One of the most prominent technologies deployed as a result of the scans is road weather information systems (RWIS), which involve installing meteorological stations along the highway that feed information into a data source for analyses. Managers can use the information to make more informed decisions during winter storms. By using RWIS, the Idaho DOT reduced crashes by 83 percent, labor by 62 percent, and material costs by 83 percent. The Wisconsin DOT reduced labor by 4 hours per person, per storm, with a snow-forecasting model combined with ice-detection systems.
Other technologies include fixed automated sensors for measuring road conditions and snowfall, integrated systems that combine global positioning systems with monitors to minimize chemical applications, and driver education programs to improve safety during adverse weather.
|Using practices encountered during a scan tour in England, the Arizona DOT included a $400,000 incentive/ disincentive in the contract for construction on State Route 68 to ensure that the contractor kept motorists moving through the work zone safely and efficiently. Lights and electronic license plate readers like these measure vehicle speed through a work zone.|
One of the most dramatic impacts of the scan program is the increased use of roundabouts in the United States. Before 1996, only a few U.S. engineers used roundabout technology. The scan program jump-started interest in roundabouts, and now more than 600 have been built, with many more under consideration.
Roundabouts can eliminate the need for signals estimated at $70,000 to $120,000 per installation and can save $50,000 to $100,000 for one-lane roundabouts on a $500,000 conventional intersection solution. Two-lane roundabouts generally cost about 30 percent less than a $1 million conventional intersection solution.
As a result of installing roundabouts, European countries have reported 40- to 70-percent reductions in crashes causing injuries and fatalities. Several initial studies in the United States have shown comparable results that also have revealed more than a 90 percent reduction in incapacitating injuries and fatalities.
Best-Value Contracting: George Washington Parkway
The U.S. Department of the Interior’s National Park Service, a principal client of FHWA’s Eastern Federal Lands Highway Division (EFLHD), owns and operates the George Washington Parkway in the Washington, DC, metropolitan area. The parkway is a four-lane divided high-way that stretches 64 kilometers (40 miles) along the Potomac River, beginning at Mount Vernon, VA, at its southern end. Four bridges, 1.6 kilometers (1 mile) from each other and spanning two creeks, are located at the northern end of the parkway. In 1998, EFLHD deter-mined that the northbound and southbound bridges needed repairs because the concrete decks had developed visible surface deterioration, exposing the reinforcing steel.
To award the contract, EFLHD chose a competitive, negotiated procurement process, in which the agency requests technical and price proposals from contractors. The contract is awarded to the most technically qualified bidder based on initial proposals received, or after negotiations are conducted to clarify any technical and pricing issues. The procurement process involves a solicitation notice indicating that the contract will be awarded based on factors other than just price, such as the time of project completion, previous performance of the contractor, and the construction methodologies employed.
For the bridges on the George Washington Parkway, EFLHD evaluated bids using the established criteria: price, time, method, and experience, followed by interviews with the top three bidders. The evaluation panel awarded the $4.2 million contract on a best-value basis to a contractor from Virginia.
The planning and coordination paid off. Construction—which began April 17, 1998, and ended June 29, 1998—was completed in 10 weekends, as scheduled. Overall costs for preliminary and construction engineering were under budget. The final cost for preliminary engineering was 9.9 percent of the construction contract (target value: 10 percent), while the final cost for construction engineering was 10.9 percent (target value: 12 percent).
In the crucial area of customer satisfaction, the project scored a 90.3 percent (target value: 85 percent) on a survey of those directly involved in completing the project, and an average of 88.6 percent (target value: 85 percent) on a survey of those involved in developing the project.
Context-sensitive design (CSD) is a collaborative, interdisciplinary approach that involves all stakeholders in developing a transportation facility that fits its physical setting and preserves scenic, aesthetic, historic, and environmental resources, while maintaining safety and mobility. CSD is an approach that considers the total context within which a transportation improvement project will exist. The movement has spread across the United States, and much of the credit is based on experiences in Europe. Information garnered from various international studies suggests that traffic calming may reduce collision frequency by 8 to 100 percent, a considerable safety and cost benefit of applying context-sensitive techniques.
In the United States, results of studies show that traffic calming has generated cost savings of nearly $10 million in Seattle, WA, with nearly 550 crashes prevented over a 4-year period. Study results also show that another approach—two-plus-one lanes (2+1 lanes)—reduced crashes and deaths in some European countries by 25 to 50 percent when compared to two-lane roads. A 2+1 facility involves conversion of a two-lane roadway to three lanes, where the middle lane serves as a passing lane on high-volume rural highways. AASHTO now is evaluating design guidance for eventual implementation in the United States.
|In 2000, the city of Clearwater, FL, constructed the Acacia roundabout near North Clearwater Beach to demarcate the transition from the commercial to the residential district and provide a traffic-calming measure to improve safe passage for pedestrians.|
Scan tours also have spawned innovative approaches to working with transportation partners and building collaboration, approaches that are especially important in a sluggish economy. In Virginia, the practice of reimbursing utilities for preliminary engineering is modeled after a process for cost sharing observed in England. The Virginia DOT reimburses utilities for 100 percent of the preliminary engineering costs incurred on a roadway improvement project.
In 2002, VDOT authorized reimbursement on more than 50 projects. The agency has noticed a small but steady increase in timely response and receipt of plans and estimates from the utilities and consultants.
"Because Virginia has had to delete more than 300 road projects from its 6-year construction plan due to the economic downturn, a true savings in dollars is hard to determine at this time," says Stuart Waymack of VDOT. "Regardless, we feel utility reimbursement is a successful program because it assists VDOT in meeting its advertisement schedules, and utilities are being relocated at a faster pace, therefore reducing the number of contractor claims due to utilities not being relocated."
|On this two-plus-one road in Germany, the center lane serves as a passing lane.|
Lessons learned during a 1999 European scan have been incorporated into an AASHTO draft report, An Informational Guide on Roadway Lighting. Issues include curfews for roadway lighting, techniques for pedestrian facilities, needs analyses for tunnels, electrical and lighting monitoring, strategies to incorporate lighting monitoring into traffic management centers, master lighting plans, visibility design techniques and pavement reflectance, techniques to illuminate roundabouts, and maintenance service levels.
A lighting scan to Switzerland in 2000 showcased a low-cost technique for illuminating crosswalks that may reduce some of the more than 5,000 pedestrian fatalities that occur in the United States annually. The method uses vertical illumination criteria to help define how much light must be placed on pedestrians to make them visible. The scan team worked with two State DOTs and a private sector partner to conduct field studies to document the improved midblock visibility of pedestrians in crosswalks. If the Swiss results could be duplicated in the United States, a number of lives could be saved.
|Using information gathered during a lighting scan in Europe, researchers in Madison, WI, used computer modeling and field studies to demonstrate how adjusting luminaire placement can help make pedestrians in crosswalks safer. Before (above) and after (below) computer images show that the European lighting not only improved the visibility of the pedestrian but also the crosswalk signage. Photo: Paul Lutkevich, Parsons Brinckerhoff.|
A Recipe for Success
By promoting relationships among Federal and State agencies and the international community through the scan program, FHWA and AASHTO are helping the United States identify, analyze, and adopt the most promising new technologies and policies. Many of the most significant changes in U.S. highway practices in recent years have come from or benefited from the International Technology Scanning Program. Even some ideas that appeared to have little chance of adoption in the United States, such as stone matrix asphalt, roundabouts, and warranties, have evolved into practice. Of course, few technologies can be applied without serious and continuous evaluation, experimentation, and, in some cases, changes in legislation or standards.
"By themselves, international scans will not improve U.S. practices," says Henry Nevares, director of the Office of International Programs at FHWA. "Only individual and organizational champions who see the potential value of a new technology and deploy it can improve practices here at home. All of the credit belongs to the implementers."
Edward Rodriguez joined the FHWA Office of International Programs in August 2003. He has worked on the FHWA contribution to the World Road Association strategic plan, known as Strategic Theme 3, and was instrumental in drafting FHWA's contribution to the Commission for Assistance to a Free Cuba report. Most recently, he has assumed responsibility for the management of the Border Technology Exchange Program, working closely with Canadian, Mexican, and U.S. border States on program development. Before joining FHWA, Rodriguez worked for several years as an attorney practicing in New Orleans.
Ted Ferragut, P.E., is the president of TDC Partners, Ltd., which specializes in identifying and moving innovative highway technology and policy into practice. He works with the public and private sectors in proactive technology partnerships. His clients include FHWA, AASHTO, the Transportation Research Board, and the National Cooperative Highway Research Program.
For more information, visit http://international.fhwa.dot.gov or contact Ed Rodriguez at 202–366–2155 or email@example.com.