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Sustainability/Sustainable Transportation

Sustainability must be a principle reflected in all our infrastructure investments, from highways and transit to aviation and ports.

DOT Secretary Ray LaHood
Before the Committee on Commerce, Science and Transportation
U.S. Senate, January 21, 2009

Greenroads: An Environmental Rating System for Design and Construction of Sustainable Roadways

Greenroads logo
The Greenroads system rates and rewards sustainably designed or rehabilitated roads, instituting a new rating tool nationwide for more environmentally conscious planning and construction.

Transportation Northwest (TransNow), University of Washington

TransNow is contributing to the development of Greenroads- an environmental rating system used to distinguish more sustainable new, reconstructed, and rehabilitated roads. The system awards credits for approved sustainable choices and practices and can be used to certify projects.

The Greenroads system provides both a holistic way to consider roadway sustainability and a defined, quantitative means to assess it. It also serves as a tool to aid decision-makers, agencies, consultants, and contractors in making informed design and construction decisions regarding sustainability.

The ultimate goal is for the Greenroads system to be used as a nationwide standard for the design and construction of more sustainable roads. This will mean less impact on the environment, lower life-cycle costs, and more positive societal outcomes. Greenroads can accomplish this by:

  • Defining basic roadway sustainability attributes.
  • Allowing a larger population to participate meaningfully in roadway sustainability.
  • Allowing sustainability tradeoffs and decisions to be made in a systematic manner.
  • Providing a means for sustainability assessment.
  • Conferring marketable recognition on sustainable roadway projects.
  • Allowing for sustainability innovation because it is end-result-oriented.

Greenroads research is progressing rapidly. TransNow is working closely with CH2M Hill to develop a rating system. An interactive website that demonstrates the rating standard and also accepts and documents applications for Greenroads certification can be found at

Information about Greenroads is being disseminated both nationally and internationally. Virginia DOT is considering using it to rate several pilot projects performed in conjunction with the Green Highways Partnership.

Additional funding was provided by the State Pavement Technology Consortium, a group of state DOTs from Washington, California, Minnesota, and Texas.

UTC Website:

Sustainable Streets: Greening Communities, Improving Mobility

Sustainable Transportation Center (STC), University of California, Davis

Sustainable streets are thoroughfares that apply sustainable-design principles, promote least-polluting ways to connect people and goods to their destinations, and contribute to livable communities.

The Sustainable Streets Project at STC highlighted connections between urban street design and sustainability and introduced a three-part framework for street design that addressed community, ecology, and movement. It also documented the plans and accomplishments of some of the country's largest cities with regard to these issues through a database of case studies that will support additional research efforts. Information was organized according to four themes:

  • Movement Plus: Higher-volume streets, redesigned to meet sustainability goals ranging from improved parking for bicycles to support of high-density residential infill.
  • Neighborhood Plus: New and redesigned neighborhoods that seek to foster community values, reduce transportation impacts, and preserve natural resources.
  • Downtown Revitalization Plus: Projects in older communities that use street design as a tool to spur economic activity and support compact and infill development downtown.
  • Stormwater Plus: Projects designed primarily to implement stormwater management features.

Public outreach was a critical component of STC's mission and was essential to the development of strategies for reducing the environmental impacts of automobiles and fostering livable communities. Project findings were disseminated via the STC website and through conferences and online symposia. An online seminar series, held in June and July of 2008 for senior staff from major U.S. cities, provided a forum for researchers and practitioners to present their work on sustainable street design and implementation to their peers and to exchange information. Recordings of the presentations are available at

Additional funding for this project was provided by California DOT's Division of Research and Innovation and the U.S. Environmental Protection Agency.

UTC Website:

Sustainable Transportation Infrastructure Solutions

University Transportation Center for Materials in Sustainable Transportation Infrastructure (MiSTI), Michigan Technological University (Michigan Tech)

MiSTI researchers have focused on the use of recycled and recovered industrial materials in transportation infrastructure. They have integrated this research into solutions for the construction, repair, and maintenance of transportation infrastructure, using their existing expertise in applied transportation materials research.

For example, the use of concrete, which relies on portland cement for its key properties, is ubiquitous throughout the world, and for every pound of Portland cement produced, current technologies produce an approximately equal amount of CO2. Identification of alternatives and additives to offset the use of cement, such as recycled concrete or recovered industrial materials, will reduce CO2 production while maintaining economic growth and development.

Traditional hot-mix-asphalt technologies rely on petroleum fuels and produce volatile organic compounds (VOCs). Researchers are investigating the use of warmmix asphalt as a possible alternative that could reduce both fossil fuel dependency and air pollution. Additionally, they are considering the use of recycled materials, such as asphalt pavement and concrete aggregate, and are coming to a better understanding of the material characteristics of recovered industrial materials, such as fly ash, slag, and cement kiln dust, which will allow them to predict the potential performance of infrastructure incorporating these materials. Use of recycled and recovered materials in pavement and infrastructure design will lead to a reduction in the carbon footprint of transportation infrastructure.

Current projects include:

  • Use of Recycled Concrete in Michigan Pavements (sponsor: Michigan DOT)
  • Specifications and Protocols for Acceptance Tests of Fly Ash (sponsor: National Cooperative Highway Research Program [NCHRP])
  • Synthesis of Railroad Engineering Best Practices in Deep Seasonal Frost and Permafrost Areas (sponsor: Alaska DOT, subcontracted to University of Alaska at Fairbanks)
  • Reduction of Minimum Required Weight of Cementitious Materials in Wisconsin DOT Concrete Mixes (sponsor: Wisconsin DOT)

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Advanced Ceramic-Metallic Composites for Lightweight Vehicle Braking Systems

Center for Transportation and Materials Engineering (CTME), Youngstown State University

New materials and applications for manufacturing processes are constantly being identified in all modes of the transportation industry. This project examines the development of lightweight components for advanced braking systems as one way to reduce vehicle weight. Gray cast iron had been the material of choice because it is inexpensive; however, it is relatively heavy, which reduces fuel economy and safety. Despite the obvious benefits of lightweight materials, most cannot withstand the stress of a braking system, and others are cost-prohibitive for general use.

Researchers are investigating the properties of interpenetrating phase composites (IPCs) produced by a unique reactive metal penetration process and manufactured by Fireline TCON, Inc. (FTi). The material structure of these composites is substantially different from that of traditional metal- and ceramic-matrix composites, and they exhibit distinctive mechanical, physical, and thermal properties. These properties can be tailored to meet the requirements of specific applications and can reduce costs. The preliminary results were very promising; the IPCs exhibited friction and wear properties similar to those of cast iron, but with half the weight and better thermal conductivity.

Working with Ohio DOT (Trumbull County), CTME researchers have been presenting the advantages of the new braking system with respect to the agency's salt trucks that operate throughout Ohio. Preliminary meetings with officials and mechanics have been encouraging. Meetings at the Trumbull County garage, which houses 30 salt trucks, have addressed the issue of reducing the weight and size of existing braking-system components with use of the new TCON braking system. This would enhance fuel efficiency and increase the system's longevity and effectiveness.

Additional project funding was received from Fireline TCON, Inc.

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Portable Petroleum Byproducts Chemical Sensor

University Transportation Research Center (UTRC2), City College of City University of New York

Petroleum-contaminated soil and groundwater are the most common contaminants encountered by transportation agencies. Contaminated soils affect the design, construction, and real-estate acquisitions of these agencies. More realistic quantities and bids, minimization of construction delays, and fair compensation for contaminated property would be achieved if "clean" zones could be delineated early in project design. Current methods for determining contamination levels require that soil and/or groundwater samples be collected and sent to an offsite laboratory for analysis, an approach that does not work well for projects with tight design schedules or when unexpected contamination is found during construction.

New York DOT spends approximately $10 to 12 million per year on soil- and groundwater-sample testing. An accurate, real-time method yielding data comparable in quality to standard U.S. Environmental Protection Agency analytical tests would be of great benefit to the state and others in the environmental field.

The purpose of this project is to develop and evaluate a portable petroleum hydrocarbon sensor based on a microconcentrator and nanoparticle fluorescence. This device will be used to test soil samples for levels of petroleum hydrocarbons that include gasoline, diesel fuel, and dielectric fluids containing polychlorinated biphenyls (PCBs). It will provide an accurate and simple field analysis, reducing the time and money spent on laboratory analysis and minimizing the downtime at construction sites waiting for laboratory results.

Several phases of the basic research needed to realize this objective have been completed. The current phase focuses on broadening the range of hydrocarbons that can be detected and developing a prototype device suitable for field use.

The project entailed an innovative partnership among New York DOT, Region 2 UTRC2, and Albany NanoTech, a high-technology research center not traditionally involved in transportation research.

Additional funding was provided by New York DOT.

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Hydrogen Fuel Vehicle Infrastructure

Hydrogen vehicle fueling-station components
Dr. John Sheffield
Hydrogen vehicle fueling-station components at Missouri S&T.

Center for Transportation Infrastructure and Safety (CTIS), Missouri University of Science and Technology (Missouri S&T)

Fast-depleting energy resources and growing environmental concerns have encouraged the development of viable, safe energy alternatives, which have become a priority for many engineers and transportation professionals.

Alternative fuel and hydrogen vehicles face many implementation challenges that must be overcome for widespread public use and acceptance. Alternative fuel properties, especially those of hydrogen, can differ drastically from those of traditional fuels such as gasoline and natural gas, creating safety concerns for potential users. CTIS researchers have been working to develop safety codes, standards, and regulations for alternative fuels to alleviate some of these concerns and add to the general knowledge base. They have also deployed a hydrogen demonstration test-bed in rural Missouri. A training session was held for community emergency first responders to acquaint them with the special concerns associated with hydrogen fuel.

CTIS researchers have also contributed to developing the new, more efficient technology needed to transition to a hydrogen economy and, specifically, to devising ways to store, transport,

Van Transport
Dr. John Sheffield
The hydrogen fuel shuttle bus at Missouri S&T.

and harness alternative energies. One solution that they have identified consists of the use of composite hydrogen storage cylinders. Pressurized hydrogen storage cylinders with appropriate emergency devices are critical components of hydrogen transportation systems, including vehicle fuel systems, bulk commodity transport, and portable and stationary storage.

The successful transition to an alternative fuel/energy infrastructure system requires fuel availability. Due to the initiative of CTIS researchers, Missouri S&T is now home to the Midwest's first hydrogen-fueling station, known as the Energy, Environment, and Education (E3, or E-cubed) Commons. In August 2008, simultaneous with its opening, the station hosted a stop on the Hydrogen Road Tour, a historic two-week, cross-country trek of a fleet of clean, efficient hydrogen vehicles, sponsored by USDOT. E3 Commons is also home to the EcoCAR Challenge Team, a student design team that will use alternative energy solutions to reengineer a Saturn VUE over the next three years.

UTC Website:

Plug-in Hybrid-Electric Vehicles: Collaborative Research

National University Transportation Center (UTC), University of Vermont

Plug-in hybrid electric vehicles (PHEVs) have emerged as a near-term technology to reduce the nation's dependence on imported petroleum, address rising gasoline prices, and decrease carbon emissions associated with the transportation sector. Vermont has a very low carbon-electric generation mix but a very high dependence on personal automobiles for travel. This study, sponsored by Central Vermont Public Service, Green Mountain Power, the Burlington Electric Department, and the Vermont Department of Public Service, examined the impact of deployment of large fleets of PHEVs in Vermont on petroleum displacement, greenhouse gas (GHG) emissions, and the electric grid. Researchers found that:

  • The existing electric grid could charge 100,000 PHEVs under a delayed nighttime-charging scenario without adding to system peaks or requiring additional generation and transmission.
  • Switching 50,000 existing vehicles from the Vermont fleet to PHEVs could reduce carbon emissions by 31 percent, NOx emissions by 30 percent, and petroleum use by 11.4 million gallons. The miles per electricity equivalent of a gallon of gasoline would be $1.05.

This project demonstrated a strong partnership between the UTC, electric utilities, policymakers, and state planners. The state has funded a second study to continue the research, which will keep focusing on the feasibility of deploying large fleets of PHEVs in Vermont, identified by the state as one of its central transportation strategies.

UTC Website:

Catalytic Converter Advanced Material Research

University of Rhode Island Transportation Center (URITC), University of Rhode Island

URITC-sponsored research by University of Rhode Island's Department of Chemical Engineering is examining the synthesis of advanced catalytic materials that could enhance automobile performance. The expected outcome is a converter that costs less to produce. Reducing the amount of platinum used in the catalytic converter by at least 50 percent will lower the cost and will make it a less attractive target for criminals. The materials have been found to be environmentally friendly due to their high performance. Maximum conversions are reached at lower temperatures, resulting in fewer pollutants in the atmosphere.

The research has also been funded by Honda. Of 700 proposals that Honda received on a multitude of topics, this was one of only five that were awarded a one-year Honda Initiation Grant (HIG). Honda renews only a small percentage of grants, but it was so impressed with the progress of the research that it renewed the HIG for two more years.

As a result of the research and testing that has been completed, Honda is pursuing two patents for catalysts, to be held jointly with the University of Rhode Island.

UTC Website:

Use of Recycled/Recovered Industrial Materials in Transportation Infrastructure

University Transportation Center for Materials in Sustainable Transportation Infrastructure (MiSTI), Michigan Technological University (Michigan Tech)

Balancing the economic costs, environmental impacts, and social attributes of transportation infrastructure is a complex problem requiring a systemwide solution. MiSTI researchers are helping state agencies and other stakeholders to explore opportunities for greater use of recycled and recovered industrial materials in the construction of transportation infrastructure.

The stakeholder community, facilitated by MiSTI and known as MichRIM, comprises representatives from MDOT and Department of Environmental Quality offices as well as the U.S. Environmental Protection Agency, material providers, contractors, and county road association members. The purpose of MichRIM is to develop a better understanding of current practices related to the increased use of recycled and recovered materials by reviewing successes in other states, looking at new applications, and attempting to identify obstacles prohibiting or restricting the use of these materials in Michigan.

Recovered industrial materials being considered by MichRIM include fly ash, blast-furnace slag, and cement- and lime-kiln dust. Recycled materials under review include concrete, asphalt, shingles, tires, and glass. These materials, which once were landfilled, are now being applied in civil infrastructure, reducing accumulating landfill waste while replacing materials that contribute to greenhouse gas emissions, carbon dioxide production, and global warming.

MiSTI, working with a subcommittee of the larger stakeholder community, is conducting "discovery calls" to individual stakeholder groups to gather independent input and feedback on agencies' roles and potential obstacles. The information obtained will serve as the basis for a white paper, which MiSTI will present to stakeholders. A technical meeting to address key issues is planned for later this year. The meeting will update stakeholders on current applications and opportunities for increased use, showcase new research, and provide a systemwide approach to understanding sustainability as it relates to transportation infrastructure.

For more information, contact

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National Wildlife Vehicle Collision Reduction Study

Wildlife Vehicle Collision Reduction Study publication cover

Western Transportation Institute (WTI), Montana State University

America's highways enable people and products to travel safely and efficiently throughout the nation. These roads cut across the habitat of many wildlife species. Collisions can and do occur between wildlife and vehicles, presenting a real danger to human safety as well as wildlife survival. State and local transportation agencies are seeking ways to balance meeting travel needs with ensuring human safety and conserving wildlife.

On behalf of the FHWA, the Western Transportation Institute, in partnership with the Louis Berger Group, Inc., completed a national study detailing the causes and impacts of wildlife vehicle collisions and identifying potential solutions to this growing safety problem. Their report, submitted to Congress in 2007, focuses on tools, methods, and other measures that reduce the number of collisions between vehicles and large wildlife such as deer because these accidents present the greatest danger to travelers and cause the most damage. The report synthesizes and analyzes research from the United States, Europe, and Australia. Researchers calculated numerous metrics to estimate the severity of the problem. Their findings included:

  • There are an estimated 725,000 to 1,500,000 crashes between vehicles and large-hoofed animals every year in the United States.
  • The annual impact on humans is more than 200 human fatalities, approximately 29,000 personal injuries, and over $1 billion in property damage.

The study identifies and evaluates 34 techniques for reducing the number of wildlife-vehicle collisions. Benefits, costs, effectiveness, implementation guidelines, and case studies are presented for each method.

Ongoing phases of the project involve the development of a manual of best mitigation practices and a training course based on the findings of the report. These technology-transfer materials will educate transportation professionals about effective collision-reduction methods and ways that they can begin to incorporate them into their own highway projects.

The report is available at

UTC Website:

The Clean Snowmobile Challenge

The University of Idaho Clean Snowmobile Team
Michigan Technological University
The direct-injected, two-stroke-powered snowmobile uses ethanol fuel, reduces pollution emissions, and decreases sound emissions while maintaining stock power and handling characteristics.

National Institute for Advanced Transportation Technology (NIATT), University of Idaho

"Yellowstone National Park and the University of Idaho have had a long-term working partnership on projects such as biodiesel de monstration and the Clean Snowmobile Challenge. NIATT's continuing support of the development of clean, quiet snowmobiles has proved to be very beneficial to Yellowstone Park and more importantly, to the National Park Service."
- Jim Evanoff, Environmental Protection Specialist, Yellowstone National Park
(informal correspondence with NIATT, August 1, 2008)

Due in part to stringent noise and air pollution control measures recently imposed on snowmobiles by the National Park Service, the Society of Automotive Engineers (SAE) instituted a student competition called the Clean Snowmobile Challenge (CSC). CSC encourages the development of a snowmobile that meets or exceeds specific required pollution and noise control measures while maintaining or improving performance. Since 2002, NIATT's Clean Snowmobile Team has won the CSC title three times.

From 2005 to 2007, the team developed a direct-injected, two-stroke-powered snowmobile, which captured first place in the CSC competition in 2007. Direct injection reduces the amount of fuel needed by the engine by eliminating unburned fuel in the exhaust. The snowmobile utilizes E-85 ethanol fuel, which doubles fuel economy, reduces pollution emissions by 80 to 95 percent, and decreases sound emissions by a factor of ten as compared with a typical snowmobile while maintaining stock power and handling characteristics.

The University of Idaho Clean Snowmobile Team
Michigan Technological University
The University of Idaho Clean Snowmobile Team received the firstplace award in the 2007 Clean Snowmobile Challenge.

The team followed the Mechanical Engineering Department's Idaho Engineering Works, an innovative model for developing leadership skills among graduate student

mentors, senior design students and other undergraduates, and faculty. This approach produces an environment that fosters professional and technical excellence by focusing on human dynamics, communication, teamwork, and professionalism.

The Clean Snowmobile Challenge is unique among SAE student competitions, as it addresses not only technology improvements but also political challenges of recreational vehicle use in sensitive environments such as Yellowstone National Park. The results that have been achieved by the University of Idaho and other universities have been very influential in the development of the Record of Decision and the implementation policy for snowmobile use in Yellowstone.

There was strong stakeholder interest in the outcome of this work, as demonstrated by the additional funding received from many private-sector companies, including Bombardier Recreational Products, Wiseco, Fastenal, Nex-Tech, E-Lab, Alaska Mining and Diving Supply, Slydog, Aristo, Klim, Jimmy G's Motorsports, Blue Ribbon Coalition, Idaho State Snowmobile Association, and Latah County Snodrifters. Funding was also provided by the College of Engineering and the Mechanical Engineering Department at the University of Idaho.

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Motor Carrier Tracking and Interdiction Study

Mineta Transportation Institute (MTI), San Jose State University

In April 2007, a petroleum tanker crashed and exploded on a freeway in Oakland, California. The intense heat affected the supporting steel's temper, literally melting the structure. This necessitated the closure of a major accessway to the San Francisco Bay Bridge, which severely impacted commuter traffic. As a result of this accident, the California DOT (Caltrans) asked MTI's National Transportation Security Center to examine whether terrorists could use similar methods to cripple the state's transportation infrastructure.

In response to this request, MTI's transportation security team conducted the Motor Carrier Tracking and Interdiction Study and developed a preliminary definition of the threat and potential remedial actions. The results were shared with state security leaders. MTI's first detailed preliminary report on longer-term security options was delivered to Caltrans and the California Office of Emergency Services within 30 days. The study is now in its second phase, which involves examining the transport of toxics as well as combustibles.

UTC Website:

Infrastructure Security and Emergency Preparedness: Emergency Evacuation in Delaware

Delaware Center for Transportation (DCT), University of Delaware

Although Delaware has never been hit directly by a hurricane or experienced the fallout from a nuclear accident, the state has plans in place to deal with such disasters. The challenge is to increase public awareness about the plans.

To provide the state with suggestions for improving the development and dissemination of its disaster plans, researchers reviewed the current documentation for hurricane evacuation in Delaware, as well as that for emergency evacuation in Delaware and neighboring New Jersey for the Salem and Hope Creek nuclear power generators. They discovered a general lack of proactiveness about emergency preparedness, noting that, though a siren system is used to warn of nuclear accidents in Delaware, people in houses with windows shut might not hear the alarms. In addition, information dissemination is largely Internet-based, and many people, including tourists, lack access to computers.

Additional project funding was received from Delaware DOT, the Disaster Research Center, the National Science Foundation, and the University of Delaware.

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A Network Robustness Index as a Transportation-Planning Tool

National University Transportation Center (UTC), University of Vermont
Transportation planning, especially when it involves highway-capacity expansion, has traditionally relied on the volume-to-capacity (V/C) ratio to identify "highly congested" or critical links. This has often resulted in localized solutions that do not consider systemwide impacts related to congestion, security, and emergency response.

Recent major catastrophic events, such as Hurricane Katrina in 2005 and the World Trade Center attacks of September 11, 2001, highlighted the need for increased consideration of robustness in network design and optimization of critical infrastructures. The dynamics of disruption models for transportation networks are different than those for other infrastructure networks, such as telecommunications and electrical power.

For the last four years, a transdisciplinary, international research group, comprising experts in engineering, business, and geography, has worked to develop the Network Robustness Index (NRI), a comprehensive, systemwide approach to identifying critical links and evaluating overall transportation-network performance. The NRI is calculated with data generally available from the transportation-planning models of most states and regions. The research is based on the premise that a fundamental change in highway network design philosophy is needed - rather than identifying individual congested or critical links, infrastructure management should focus on maximizing the robustness of the overall transportation system and on minimizing system vulnerability.

Unlike other measures, the NRI accounts for both networkwide demand and traffic rerouting. It can also be used for emergency and security purposes to evaluate the overall resiliency of the network to disruption.

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Symposium on Climate Change and Transportation: Impacts and Solutions

University of Massachusetts Transportation Center (UMTC), University of Massachusetts, Amherst

The University of Massachusetts Transportation Center and H3B Media Ltd. cosponsored a Climate Change Think Tank Symposium on May 29–30, 2008. The symposium provided a venue for some 75 industry leaders and government representatives to share information about how transportation contributes to climate change, as well as the environmental impacts of climate change on the U.S. transportation infrastructure. The interrelationship between climate change and the planning, management, and operations of transportation facilities and services was also addressed.

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