February 2010 – Vol. 4, No. 1 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

Member Profile: Northland Chapter of ATSSA

Since 1969, the American Traffic Safety Services Association (ATSSA), an international trade association, has represented companies and individuals in the traffic control and roadway safety industries. ATSSA members provide the safety features, services, and material used on America's roadways. ATSSA nationally has 1,600 members that are committed to an environment where roadway safety is always improving.

The Northland Chapter of ATSSA, which joined TERRA in July, draws its membership from city, county, and state agencies as well as private industry in North Dakota, South Dakota, Minnesota, and western Wisconsin. Both the Northland Chapter and National ATSSA are concerned with keeping roadways safe for roadway workers and the motoring public.

“It is our desire to stay up-to-date with the latest technology in work-zone safety, signage, pavement markings, lights, signals, and roadway worker training,” said Emily Fischer, president-elect of the Northland Chapter of ATSSA and the organization’s representative on the TERRA Board. “We also believe that this is best done in concert with both government and private-sector companies.”

The involvement of the Northland Chapter of ATSSA with TERRA was a natural fit. Like TERRA, the Northland Chapter of ATSSA is concerned about the safety and durability of pavements as well as related transportation engineering challenges.

“ATSSA recognizes the importance of strength in numbers and being able to pool money together for a common good,” said Fischer, who is employed as national sales manager for SignCAD Systems in Minnetonka, Minnesota. “The Northland Chapter wishes to have a voice with TERRA and the possibility to research things that we are passionate about. We see TERRA as a more effective vehicle in getting research accomplished.”

Research priorities of the Northland Chapter of ATSSA include sign sheeting material, the effect of font size and type on readability, pavement markings (especially wet reflectivity and durability), guardrails, lighting and signals, and work-zone traffic control devices. Further, the organization is interested in how new technology in these areas affects mobility and safety.

Among the pavement and infrastructure research innovations Fischer expects to see soon: LED lighting, smart work zones, a proportional grid system, a new font for guide signs, and changes in how pavement is placed to accommodate flush inset pavement markings and motorist technology information systems.

“One of our biggest challenges,” Fischer said, “is in educating public- and private-sector employees as to how all of this integrates together to ensure efficient, effective, and safer roads. Pavement alone does not get us there.”

Member Highlights

The Minnesota Department of Transportation (Mn/DOT) is contributing additional funding through this biennium for a position to support TERRA program development, research projects, implementation activities, and communications and marketing. Roger C. Olson, P.E. (651-366-5517, roger.olson@state.mn.us), a long-time Mn/DOT research operations engineer, has been assigned to provide part-time technical support for TERRA. The support is needed to assist in delivering benefits to members as membership has expanded to include seven government agencies, eight private sector entities, and three universities.

Projects and Initiatives

Chairman Oberstar sees TERRA as a model for road research

U.S. Rep. James L. Oberstar, chairman of the House Transportation and Infrastructure Committee, met with the TERRA Board at the University of Minnesota in November for an update on TERRA research activities.

TERRA co-chair André Clover and Marketing and Communications Committee co-chair Fred Corrigan welcomed Oberstar and provided an overview of the organization. Board members and resource staffers took turns around the table introducing themselves, each briefly explaining their connection to TERRA as well as their key research interests.

Oberstar learned about several TERRA publications, activities, and research projects during updates from TERRA Marketing and Communications Committee co-chair Keith Shannon and Research and Implementation Committee chair Mark Maloney. Maloney also previewed the upcoming TERRA-sponsored pavement conference at which Oberstar is scheduled to deliver remarks via video.

In addition, Maloney and MnROAD manager Maureen Jensen described the TERRA research program and key priorities, emphasizing the value of partnerships to the research process and to the successful implementation and broad application of research findings.

Several TERRA members in attendance thanked Oberstar for his continued support of road research and stressed the need for additional funding as federal lawmakers craft the successor to SAFETEA-LU, which has been temporarily extended since expiring in October.

"As you can see around the table, there is a lot of excitement and commitment from this group, and more interest in participation,” Corrigan told Oberstar. “It wouldn’t happen without you and the support of folks like you and your committee.”

Oberstar, a self-professed “transportation junkie” fascinated with the results of transportation research as well as seemingly every aspect of transportation policy, also expressed his gratitude for the “combined intellectual energy” among TERRA members dedicated to road research.

“We need your input,” Oberstar said, “to structure the road itself, the materials on the top, and stretch the longevity of our road and bridge surfaces in light of increased pressure—3 trillion miles driven every year in the U.S.”

Oberstar, especially noting the need for more research into truck-weight issues, roadway materials, and environmental concerns, encouraged TERRA efforts to improve road surfaces and longevity to meet an ever-increasing demand in the face of rising costs and limited public funds.

 “What can we do to invest better in more sustainable road surfaces? [TERRA] gives us an opportunity to answer that question,” he said. “The answers are right here around this table.”

Oberstar recognized TERRA as a model for improving the efficiency and cost-effectiveness of the transportation research process. “This is the kind of format we need to better serve transportation,” he said. "I love what you're doing here."

Preliminary findings in farm roads study implicate repeated heavy loads

Preliminary findings from a TERRA-initiated research project studying the effects of farm implements on rural roads suggest that the pavement of a typical 7-ton rural road is not strong enough to support repeated applications of heavy loads. The findings are summarized in the new TERRA fact sheet Impacts of Heavy Farm Equipment on Rural Roads.

The farm equipment study, through the FHWA Transportation Pooled Fund, was begun in 2008 to study pavement response under selected agricultural equipment and a typical 5-axle semi-trailer truck. Two sections of a specially constructed "farm loop" test track at MnROAD were instrumented with different types of electronic sensors to measure pavement responses, such as stress and strain. One section, with 5.5 inches of hot-mix asphalt (HMA) and a 9-inch gravel base, represents a typical 10-ton road. The other, with 3.5 inches of HMA and 8 inches of gravel, is a typical 7-ton road.

In spring 2009, researchers observed extensive rutting on the 7-ton section, which is paved with a thinner layer of asphalt. This failure illustrates the importance of spring load restrictions for this type of pavement. During fall 2009 testing, more damage was detected on another part of the 7-ton section.

Earlier test results in spring and fall 2008 demonstrated that axle load has a pronounced effect on pavement stress—the stress increased with axle load. For flotation tires, the pavement-tire contact area increased with load. The data also indicated that the bottom of a pavement could undergo fatigue from tension to compression depending on wheel location.

Three more cycles of testing are planned, in spring and fall of 2010 and spring 2011, for the study, officially titled “The Effects of Implements of Husbandry ‘Farm Equipment’ on Pavement Performance,” TPF-5(148). Additional findings will be disseminated as more data are collected and analyzed.

This pooled-fund project includes contributions from Iowa DOT, Illinois DOT, Wisconsin DOT (WisDOT), the Minnesota Local Road Research Board (LRRB), the Professional Nutrient Applicators Association of Wisconsin (PNAAW), and Mn/DOT. WisDOT, LRRB, and Mn/DOT are TERRA members. Many industry partners, including equipment and tire manufacturers and farm applicators, are participating in the project and contributing equipment and labor.

The pooled-fund project will conclude in fall 2011.

Related resources:

• Impacts of Heavy Farm Equipment on Rural Roads (TERRA fact sheet)
• Effects of Husbandry "Farm Equipment" on Pavement Performance [TPF-5(148)] pooled-fund project

NCHRP publishes new guide to rumble strips

The National Cooperative Highway Research Program published in late 2009 a comprehensive synthesis report on rumble strips, Guidance for the Design and Application of Shoulder and Centerline Rumble Strips (NCHRP Report 641). TERRA has summarized the highlights from the report and other sources in a new fact sheet, Shoulder and Centerline Rumble Strips.

Rumble strips—grooved patterns usually applied in a longitudinal direction along a shoulder, edgeline, or centerline of a road—have proven to be a relatively inexpensive and effective crash countermeasure. It is estimated that 20 percent of serious crashes involve drunk or drowsy driving; rumble strips are effective because the noise and vibration produced alert drivers when they stray from their lane.

Further, rumble strips are effective in preventing both head-on sideswipe incidents and single-vehicle run-off-road (SVROR) crashes, which a third of all fatal crashes. Twice as many SVROR crashes occur on rural roads, due to a combination of higher speeds and more driving miles. Rumble strips are now a regular fixture on many roads and highways in rural and urban zones. Shoulder rumble strips are used in 46 of 50 states.

Rumble strips differ by placement and function. Shoulder strips are installed on the outside of the lane, to alert drivers when they stray onto the shoulder. Centerline strips, installed primarily on rural roads, jar drivers when they drift into the opposite lane, and are less prevalent than shoulder strips. Transverse strips are installed perpendicular to the direction of travel, to alert drivers when they are approaching important locations, such as intersections or toll plazas.

A fourth category of rumble strip, called midlane strips, is currently experimental. They are designed for placement in the center of each travel lane, between the paths of the vehicle's wheels, and would theoretically fill the role of both the shoulder and centerline strips. Some designers fear they may be a further distraction for drivers and could even endanger motorcycles. There are currently no midlane strips in the United States.

Some general concerns about rumble strips present research opportunities. Obviously, rumble strips cause noise, which can anger nearby residents. Sound barriers, restrictions on strip use in residential areas, and placing strips further from the travel lane offer potential solutions.

Another major concern is for cyclists, since rumble strips placed on shoulders may impede and endanger the ability to control a bicycle on rural road shoulders. Narrower strips and skip patterns offer potential solutions.

Research is also needed to further quantify the safety effectiveness of rumble strips on a wider variety of roads. 

Related resources:

• Shoulder and Centerline Rumble Strips (TERRA fact sheet)
• Guidance for the Design and Application of Shoulder and Centerline Rumble Strips (NCHRP Report 641, 2009)

Announcements

TERRA-sponsored pavement conference scheduled for Feb. 11

TERRA is sponsoring the 14th Annual Minnesota Pavement Conference, scheduled for February 11, 2010, at the University of Minnesota Continuing Education and Conference Center in St. Paul, Minnesota. Cosponsors include Mn/DOT, the Minnesota Local Road Research Board (LRRB), the Minnesota Local Technical Assistance Program (LTAP), the University of Minnesota Department of Civil Engineering, and several others.

This year's conference will highlight innovative low-volume road construction practices, environmentally sensitive road construction and maintenance techniques, and the issue of heavy traffic and loads. In addition, U.S. Rep. James L. Oberstar, chairman of the House Transportation and Infrastructure Committee, will address the conference by video about infrastructure needs and priorities in the new federal surface transportation authorization act. In addition, Bernie Arseneau, Mn/DOT director of policy, safety, and strategic initiatives, will speak on behalf of Mn/DOT commissioner Tom Sorel.

This one-day conference also will present sessions that look at the implemention of new pavement research and technology. National and local trends and innovations will be examined to expand understanding of pavement challenges and solutions.

The conference is intended for researchers, city engineers, county engineers, public works officials, maintenance superintendents, design engineers, consulting engineers, and others interested in pavement issues. A brochure with a registration form and instructions (540 KB PDF) is available online. For more information about the 14th Annual Minnesota Pavement Conference, visit the TERRA Events page, or contact cceconf2@umn.edu or 612-624-4754.

TERRA publishes 2009 highlights

TERRA has published a two-page report highlighting the organization's activities and accomplishments during the past year. The document provides a brief overview of research, engagement, and communications efforts, crediting the committed service of its members, the TERRA Board, and three active committees structured around the organization's strategic directions. TERRA 2009 Highlights and other TERRA publications are available for download from the TERRA Web site publications page.

TERRA publishes fact sheets about rumble strips and farm implements

TERRA has published two more fact sheets, Shoulder and Centerline Rumble Strips and Impacts of Heavy Farm Equipment on Rural Roads. The former focuses on shoulder and centerline rumble strips, which are considered low-cost, highly effective safety measures. The later fact sheet focuses on the preliminary findings from a TERRA-initiated pooled-fund study of the effects of farm equipment on rural roads. Each TERRA fact sheet provides details about the latest research for each topic and lists several resources for further information. Both fact sheets are described in separate articles in this issue of TERRA E-News. In addition, all TERRA fact sheets are available for download from the TERRA Web site.

MAPA aphalt events planned

The Minnesota Asphalt Pavement Association calendar includes three upcoming events:

• Flagger Train the Trainer Course, February 12, 2010 (8 a.m. to noon), at the Mn/DOT Arden Hills Training Center
• 54th Annual Asphalt Contractors' Workshop, March 3, 2010, at the Earle Brown Heritage Center in Brooklyn Center
• Flagger Train the Trainer Course, April 16, 2010 (8 a.m. to noon), at the Mn/DOT District 3 Office in St. Cloud

For more information, contact MAPA at info@mnapa.org or 651-636-4666.

ATSSA annual convention and traffic expo, Feb. 14-18

The American Traffic Safety Services Association (ATSSA) annual convention and traffic expo is celebrating its 40th year. This year's convention, "From the Roadway of the Past to the Highway of the Future," will be held in San Antonio, Texas, February 14-18, 2010. The 2010 convention—for traffic control, engineers, managers, and more—includes roundtable sessions designed to facilitate a peer-to-peer exchange, workshops delivered by industry experts, and nearly 100 hours of training and certification programs. The traffic expo provides an opportunity to preview safety products and services with more than 200 roadway safety suppliers.

Northland Chapter of ATSSA annual safety training workshop, Mar. 16-17

The Northland Chapter of ATSSA will hold its annual "How To" Training and Education Conference "Safety Depends on You!" on March 16 and 17, 2010, in Fargo, North Dakota. The conference is open to city, county, state, and federal agencies as well as consulting engineers and contractors. The conference is intended for field-level installers, supervisors, and designers who work in the areas of work-zone traffic control, permanent signing, and pavement marking.

CPAM annual concrete paving workshop, Mar. 18-19

The Concrete Paving Association of Minnesota has scheduled its annual concrete paving workshop for March 18 and 19, 2010, at Breezy Point, Minnesota.

International conference on sustainable concrete pavements, Sep. 15-17

The International Conference on Sustainable Concrete Pavements: Practices, Challenges, and Directions is scheduled for September 15—17, 2010, in Sacramento, California. The conference, organized as a part of technology transfer activities under the Advanced Concrete Pavement Technology Products Program that operates within the Federal Highway Administration, will provide an international forum to discuss the sustainable attributes of concrete pavements. Featured presentations will cover existing technologies, emerging research, approaches to measuring energy and environmental impact, user considerations, and international practices and experience. The forum will present improved and innovative processes for achieving sustainable concrete pavements throughout the pavement's life cycle.

Green streets and highways conference, Nov. 14-17

The American Society of Civil Engineers and the Transportation & Development Institute has scheduled the 2010 Green Streets & Highways Conference on November 14–17, 2010, in Denver. This conference is being held to address the rapidly growing interest and activity in sustainable transportation. In addition to opening and closing plenaries, the conference offers seven sets of concurrent technical sessions.