August 2009 – Vol. 3, No. 3 Partnering for Roadway Innovation

TERRA E-News is a quarterly electronic newsletter of the Transportation Engineering and Road Research Alliance. TERRA E-News brings you the latest research on pavement, materials, and related transportation engineering challenges, including issues related to cold climates.

Member News

New Members: NDDOT and the ATSSA Northland Chapter

The North Dakota Department of Transportation (NDDOT) and the Northland Chapter of the American Traffic Safety Services Association (ATSSA) joined TERRA in July. NDDOT joined through a pooled fund recently established to provide more state DOTs the opportunity to become a member of the alliance. Tom Bold, pavement design and research supervisor with the NDDOT Materials and Research Division, will represent NDDOT and Emily Fisher of SignCAD will represent the Northland Chapter of the ATSSA on the TERRA Board.

Member Profile: New York State Department of Transportation

The New York State Department of Transportation (NYSDOT) became a member of TERRA in February through the recently established pooled fund for state DOTs. Gary Frederick, NYSDOT director of transportation research and development, said NYSDOT joined because TERRA provides a valuable avenue of communication for its member organizations. "The TERRA pooled fund enables states to participate so that collaboration will become the norm," he explained.

“Joining TERRA was an easy decision,” Frederick added. “Coordination doesn’t happen on it’s own. You’ve got to make it happen.”

According to Frederick, TERRA’s ability to facilitate innovative partnerships allows interested agencies to expand their knowledge base of implementable research and to coordinate future research goals. Practically speaking, TERRA membership allows NYSDOT to stretch its limited budget. Moreover, coordination with other members and access to a larger base of knowledge furthers the department’s drive for constant improvement. “We’re always striving to do better,” Frederick said.

NYSDOT is responsible for a diverse set of mini-climates within the state that present a wide variety of transportation challenges. The department faces many of the same challenges as other state DOTs, including falling tax revenues, shrinking budgets, and aging infrastructure, while striving to meet the needs of an integrated, global economy.

Charged with the development and operation of highways, railroads, mass transit systems, airports, and waterways in the State of New York, NYSDOT oversees a large network of more than 113,000 miles of highway, 16,000 bridges, a 4,600-mile rail network, more than 500 public and private aviation facilities, 130 public transit operators, and 12 major public and private ports.

In addition to research aimed at improving technologies and methods, the environment has been a top research priority for NYSDOT. The department already has conducted extensive research into air pollution, water quality, and wildlife impacts, and plans to incorporate into its research a greater focus on global climate change, carbon footprints, and energy concerns. NYSDOT research, for instance, is looking into the use of energy-efficient LED lights on freeways and at rest areas, the development and implementation of road salt reduction strategies, and the implementation of effective methods for composting roadkill.

Member Highlights

Shoreview Public Works Director Mark Maloney, chair of the TERRA Research and Implementation Committee, was featured in a Star Tribune article (May 26, 2009) about his city's innovative use of pervious concrete to prevent runoff and eliminate the need for storm sewers. Also mentioned was the Minnesota Department of Transportation (Mn/DOT) partnership with the Aggregate Ready Mix Association of Minnesota (ARM of MN) to study pervious concrete at MnROAD. Maloney is one of two Minnesota Local Road Research Board representatives on the TERRA board. Mn/DOT and ARM of MN also are TERRA members. The story also appeared on KARE-11 TV News (May 27, 2009) and in Aggregate Research magazine (May 27, 2009). For more information, see an ARM of MN slide presentation about the project (6.8 MB PDF). More >>

Projects and Initiatives

TERRA Innovation Series: Michigan event features asset-management software tools and project site visits

Representatives of cities, counties, and DOTs from the upper Midwest converged upon Grand Rapids, Michigan, on July 13, for a half-day TERRA Innovation Series event to learn about Michigan’s asset-management initiative, widely considered a model system. County road commissions, cities, villages, planning organizations, the Michigan Tech Transportation Institute (MTTI), and the Michigan Local Technical Assistance Program (LTAP) have worked together to support implementation of the system at large and small agencies.

Michigan is changing the culture of local roadway management using a multifaceted approach that includes educational opportunities for wide audiences, a condition-assessment system that makes sense for local agencies, analysis tools that make GIS infrastructure management accessible, and technical support that makes the entire process doable.

TERRA hosted the Michigan event, held just prior to the 2009 AASHTO Mississippi Valley Conference also in Grand Rapids, in cooperation with the Michigan Department of Transportation (MDOT), MTTI, and Michigan LTAP. The afternoon began with a 90-minute bus tour through six locations in the Grand Rapids area that demonstrated a variety of innovative construction and asset-management practices. After the tour, the focus shifted to Michigan’s experience with statewide implementation of transportation asset management.

TERRA co-chair Julie Skallman, director of the Mn/DOT State Aid Division, welcomed attendees along with MDOT Grand Region engineer Roger Safford and MTTI director Larry Sutter. Next, speakers provided a context for transportation asset management as well as identified associated challenges, specific asset-management software tools, and examples of successful implementation.

Carmine Palombo, director of Transportation Programs for the Southeast Michigan Council of Government (SEMCOG) and chair of Michigan’s Transportation Asset Management Council (TAMC), gave an overview of progress made over the past few years since the legislature established the council. Since selecting PASER (Pavement Surface Evaluation and Rating) as the statewide pavement condition rating system, five years of condition data have been collected on 84,000 miles of federal aid roads, and in 2008, organized condition assessment began on the non-federal aid local network. In 2009, work began on populating the predictive model in RoadSoft for the entire federal aid network.

Terry McNinch, director of the Michigan LTAP and the Technology Development Group at MTTI, provided the specifics of Michigan’s asset-management efforts that have prompted implementation at the local agency level. He pointed to the City of Manistee and the Roscommon County Road Commission as examples of successful implementation.

Steve Warren, deputy director of the Kent County Road Commission and a member of the TAMC, provided a summary of how his agency has dealt with asset-management implementation and most important, the change in organizational culture that had to come with it.

Finally, Tim Colling, research engineer and Michigan LTAP assistant director, provided an overview RoadSoft, the roadway infrastructure management system used by more than 280 county road commissions, cities, and villages throughout Michigan, and now available for license outside Michigan. He demonstrated the system’s capability to run scenarios using various pavement treatment strategies and budget levels.

TERRA co-chair Tim Worke, director of the Transportation and Highway Division with the Associated General Contractors of Minnesota, provided closing comments.

The event was the third in the TERRA Innovation Series, which began in 2007 with an open house featuring the reconstruction of Highway 36 through North St. Paul. Last year, an open house at MnROAD showcased how materials and pavement engineering innovations are developed, tested, and implemented on Minnesota roads. The Innovation Series events have a technical focus and address research results, trends that affect or improve productivity, innovative partnering and contracting models, and hot topics that may lead to new research related to TERRA priorities.

Related resources:

• TERRA Innovation Series—Transportation Assets: Innovative Tools for More Effective Management event page

TERRA research projects featured at CTS transportation research conference

Several TERRA research projects and researchers were featured during two days of presentations at the 20th Annual Center for Transportation Studies (CTS) Transportation Research Conference, held May 19 and 20 in Bloomington, Minnesota. The conference acts as a forum for researchers and practitioners from Minnesota and the Upper Midwest to share their research findings in a variety of transportation-related areas.

Bernard Izevbekhai, concrete research operations engineer with the Mn/DOT Office of Materials and Road Research, presented an evaluation of tire-pavement interaction noise (TPIN) using on-board sound intensity (OBSI) technology. Much of the research has been conducted at the MnROAD facility, where he measured the TPIN of various pavements. Results revealed the effect of texture, pavement stiffness, pavement age, and traffic levels on TPIN. A related TERRA pooled-fund project—TPF-5(134) —is studying ways to rehabilitate portland cement concrete (PCC) pavements using innovative diamond grinding to minimize noise while providing a safe, smooth, and durable surface.

Jill Thomas, associate director of the Minnesota Asphalt Pavement Association, discussed warm-mix asphalt (WMA) as an important step in sustainable development, simultaneously conserving natural resources, reducing the carbon footprint of the industry, and improving the quality of pavements that we all rely on. WMA technologies employ a variety of methods and materials—what they have in common is the ability to drastically reduce the temperatures at which pavement material is produced and placed on the road. WMA, a relatively new technology to Minnesota, is the focus of several research test cells at MnROAD. The potential benefits include extending the paving season in cold climates, improving quality, and lengthening the lifespan of the pavement.

Shongtao Dai, research operations engineer with Mn/DOT’s Office of Materials, gave an overview of the TERRA-initiated project titled “The Effects of Implements of Husbandry ‘Farm Equipment’ on Pavement Performance.” Over three years, researchers are testing how pavement responds to various configurations of agricultural equipment with live loads on the MnROAD farm loop to capture the seasonal variation in pavement strength and response to heavy loading. The test roadway, constructed in 2007, is typical of many rural, low-volume county roads. Over the past few decades, significant changes in both farm size and farm equipment have prompted the farm equipment industry to produce larger application equipment.

Related resources:

• An On-Board Sound Intensity Evaluation of MnROAD Pavements presentation
  (1.5 MB PDF)
• Keep it Cool With Warm Mix Asphalt presentation (1.3 MB PDF)
• Effects of Husbandry “Farm Equipment” on Pavement Performance pooled-fund project

Seminar offers international solutions for quieter pavements

Representatives of Scandanavian transportation agencies, as well as members of Minnesota transportation agencies, presented a seminar on quiet pavement technologies in May at the University of Minnesota. TERRA, along with the Pavement Research Institute, the University of Minnesota, and the Minnesota Department of Transportation (Mn/DOT), sponsored the seminar.

Hans Bendtsen, senior researcher at the Danish Road Institute of the Danish Road Directorate and manager of their Noise Program, presented European experiences with noise-reducing pavements. He reported an increasing interest in noise-reducing pavements in Europe, primarily because of pressure from populations to minimize road noise in developed areas. Noise-reducing pavement is the second most commonly used form of roadway noise abatement in Europe, behind noise barriers.

Currently, Denmark, the United Kingdom, and the Netherlands have policies in place for the use of noise-reducing pavements. The Netherlands uses a porous asphalt wearing course on its entire main road network, covering almost 80 percent of roads. The United Kingdom uses a different type of noise-reducing pavement—thin surface course system—on all new construction and road repair projects. Denmark is in the process of developing a quiet pavement policy.

According to Bendtsen, all three countries are quite satisfied with their use of noise-reducing pavements. They find them to be a cost-effective noise abatement solution, especially when used with other tools such as noise barriers.

Bernard Izevbekhai, concrete research operations engineer with Mn/DOT, offered a presentation on Minnesota's experience with quiet pavement technologies. He gave an overview of Mn/DOT pavement surface types, noting that porous pavements, new bituminous, and innovative diamond-ground concrete pavements exhibited low initial noise. Furthermore, he showed the unique acoustic durability exhibited by each pavement surface type. Izevbekhai accentuated the relationship of tire-pavement noise, surface-texture sound absorption, and friction. The Mn/DOT pavement surface characteristics studies are aimed at optimizing safety, low noise, and durability over the pavement surface life.

Mats Wendel of the Swedish Road Administration gave a presentation on Sweden's model for selecting low-noise pavements. In Sweden, noise and dust emissions are a major traffic issue. Sweden has a unique problem in the widespread use of studded tires, which are more damaging to roadways than normal tires. Some of the most effective noise-reducing pavements are not strong enough to hold up and will clog under such conditions. Because of these studded tires, the most common pavement in Sweden is stone matrix asphalt (SMA) 16, an extremely noisy pavement. Because of this, Sweden has focused on building insulation and noise wall techniques for noise control. Still, there is an interest in finding a low-noise pavement that is durable enough to withstand use by studded tires. Sweden has added noise emissions, dust emissions, and rolling resistance to its criteria for pavement selection, along with traditional factors such as durability and cost.

Related resources:

• View webinar recording
• Noise Reducing Pavements—Internationally! (Nordic Road and Transport Research)
• Pavement Surface Characteristics (Mn/DOT Materials and Road Research)
• Project aims to improve PCC surface characteristics with diamond grinding (TERRA E-News)

Highway 36 research examines planning options for highway reconstruction

Construction projects on major urban highways can dramatically impact travel options for thousands of travelers as well as the businesses that rely on the affected roadway for customer access. The Minnesota Department of Transportation (Mn/DOT) decision to completely close a section of Trunk Highway (TH) 36 through North St. Paul, Minnesota, for five months for reconstruction was the subject of intense public debate.

Reconstruction of Highway 36 was also the topic of the first TERRA Innovation Series event, held in November 2007 as the major portion of the project concluded and the road was reopened. The reconstruction of TH 36 was the largest full closure of a highway in Minnesota history.

Mn/DOT funded a study of full closure because it is a relatively new strategy for addressing present-day transportation network needs in Minnesota. The study sought to evaluate all traffic operation alternatives in the greater project area, compare costs and benefits with other construction alternatives, conduct market research to identify the public’s acceptance of the project during and after completion, and identify lessons learned.

John Hourdos, director of the Minnesota Traffic Observatory (MTO) at the University of Minnesota, led a study of the closure, comparing the effects of the five-month full closure to an alternative multi-year partial closure scenario in terms of construction costs and costs to road users. Hourdos presented findings from the study at a seminar in April sponsored by the University of Minnesota Intelligent Transportation Systems (ITS) Institute.

Researchers traced the project’s complex history—from plans for the addition of a single pedestrian bridge in 1997 to its final form, which included the reconstruction of several intersections—and gave an overview of the innovative contracting provisions implemented by Mn/DOT to assure timely completion. The agency required that delays and other road-user costs be explicitly considered in the contracting phase of the project. In the end, Hourdos said, the full-closure option was the only economically feasible option given budgetary restrictions facing local and state agencies at the time.

Three research models produced comparable results and confirmed that a partial closure would have been more expensive. But the differences in complexity and data requirements, Hourdos said, were significant. He noted that the project broke new ground in the analysis of full closure while confirming the value of engineering judgment and uncovering deficiencies in current procedures and tools.

Related resources:

• Watch the seminar online
• Minnesota Traffic Observatory

Announcements

TERRA publishes fact sheet about warm-mix asphalt

TERRA has created a fifth in its series of fact sheets, this time focusing on warm-mix asphalt. Warm-mix asphalt (WMA) is the generic term for a variety of technologies that allow the producers of hot-mix asphalt (HMA) pavement material to lower the temperatures at which the material is produced at the HMA plant and placed on the road. Lowering the temperature of asphalt mixes decreases fuel usage, fumes, and greenhouse gas emissions, preserving resources while addressing growing environmental sustainability. Potential engineering benefits include better compaction on the road, the ability to haul paving mix for longer distances, and the ability to pave at lower temperatures. The fact sheet provides details about the latest WMA research and lists several resources for further information about WMA. All TERRA fact sheets are available for download from the TERRA Web site.