Hot Topics is our electronic newsletter highlighting new publications and resources from a variety of sources.
Roadway departures cause nearly half of Minnesota’s traffic fatalities. The Safety Edge, a beveled or sloped pavement edge, is a low-cost countermeasure to prevent such crashes.
As part of its Safety Edge effort, the Federal Highway Administration (FHWA) is evaluating demonstration projects to document the safety, constructability, and quality of the innovation. One open house was held on October 7 in Dodge County, Minnesota. Sponsors were Dodge County, the FHWA, the Minnesota Department of Transportation (Mn/DOT), and Minnesota LTAP.
The Safety Edge replaces vertical drop-offs with a 30-degree slope at the edge of the pavement, giving drivers a better chance to recover safely if they drift off the road.
"Because we have so few sections [with the Safety Edge], and they tend to be on lower-volume roads, we don't have a significant number. But everything seems to be better, and our best estimate right now is a 5.7 percent reduction in all crashes," said Cathy Satterfield with the FHWA Office of Safety.
In Iowa, the FHWA has worked with state and county officials and contractors to hold three demonstrations since 2008, each with an open house, to showcase the safety edge. Success with the technique led the Iowa Department of Transportation to adopt a policy requiring it on all projects with a paved shoulder less than 4 feet wide.
Check out some photos from the Dodge County open house (see slideshow).
Read more about Iowa’s efforts in the August/September 2010 issue of the FHWA’s Innovator newsletter.
Learn more at the FHWA’s safety edge website.
Hitting an uneven pavement edge or an obstacle like a manhole cover gives a jolt to tractor-mounted snow blowers. This jolt usually means the snow blower has come to an instant dead stop—a real safety hazard for the operator. The machinery may also be damaged, and snow is not completely cleared away.
A new mechanical linkage technology developed in part with Local OPERA funding—the Cushion-Release Push Frame—helps a blower “walk” over obstacles by absorbing the impact. On a plow equipped with the push frame or the skidsteer attachment, the cutting edge will raise to different heights, depending on construction specifications. The snow blower lifts to approximately 1.5 inches, says inventor Grant Hanson of the City of Glenwood. The push frame can be installed on snow blowers, front-end loaders, and other equipment.
The technology offers several benefits, Hanson says. It allows operators to scrape rugged surfaces continuously so a second pass isn’t needed for residual snow, and it can reduce downtime from mechanical breakdowns. But the “the biggest advantage,” he says, “is the safety aspect.”
The Glenwood public works department received OPERA funding to develop the technology, and a Glenwood manufacturer has begun building them.
The Local Operational Research Program (OPERA) is a program of the Minnesota Local Road Research Board (LRRB). The OPERA annual report will be posted in January.
More information about the push frame
A short video clip of the push frame in use (22 seconds).
Mn/DOT’s Office of Maintenance has published a Winter Chemical Catalog. The document provides contact information for an array of deicer vendors as well as background information about deicing chemicals and their impact on infrastructure and the environment.
Mn/DOT’s 2009–2010 Annual Winter Maintenance Report (4.5 MB PDF) describes key facts and statistics and reviews the department’s efforts to conserve winter chemicals. It also describes four innovations from Mn/DOT’s Maintenance Operations Research program: calibration scales, tow plows, a portable blending station, and a carbide-insert plow blade.
More about Mn/DOT’s Maintenance Operations Research program, including links to guidelines on anti-icing and calibration
Many urban mailboxes are installed improperly, putting them at risk for damage during winter maintenance operations. The City of Eagan created several documents to educate the city council and residents on the need for proper mailbox installation:
Download the materials from the LRRB Web site
Mn/DOT has published new guidelines for the design of turn lanes.
For the project, investigators identified how variables such as turn-lane location, vehicle speeds, volume, type of intersection control, fraction of heavy commercial vehicles, and roadway geometry affect turn-lane storage capacity and room for deceleration. They developed a process to determine optimal turn-lane lengths that considered all of these factors.
Investigators then created a turn-lane design checklist and provided example calculations for each of eight Mn/DOT facility types and locations: conventional or expressway, signalized and unsignalized in both rural and urban settings.
The resulting guide provides design engineers with step-by-step worksheets for determining safe and functional turn-lane lengths based on the specific characteristics of each intersection.
Design of Turn Lane Guidelines (October 2010, 2010-25) and a corresponding technical brief, Putting Research into Practice: Guidelines for Designing Turn Lanes (October 2010, 2010-25TS), are available on the Minnesota LRRB Web site.
Motorists who use the Interstate 94/Hwy 95 interchange in Woodbury are among the first in the nation to encounter a new traffic signal design that minimizes unnecessary waiting for motorists and improves safety.
Activated earlier this fall, the new signals feature a flashing yellow arrow, in addition to the standard red, yellow, and green arrows. When illuminated, the flashing yellow arrow allows waiting motorists to make a left-hand turn after yielding to oncoming traffic. Otherwise, the new traffic signals work the same as traditional signals.
Read the full article in the September 8, 2010, Mn/DOT Newsline.
Read more about the new flashing yellow arrow signals.
The annual Toward Zero Deaths (TZD) Conference in October attracted more than 700 participants. View presentations and handouts.
The TZD conference was followed by a workshop attended by 150 people that featured a delegation from Sweden. Some of the innovations Swedish presenters talked about include:
Read the full article in the October 27, 2010, Mn/DOT Newsline.
The Federal Highway Administration conducted the Local Road Safety Domestic Scan in fall 2009 to identify and document noteworthy practices in planning, programming, and implementation used by state and local agencies to improve local roadway safety.
The scan report describes processes, methods, and techniques the seven scan states have employed to effectively improve the safety of their local road network. These include:
Download Addressing Safety on Locally Owned and Maintained Roads—A Domestic Scan.
In October the FHWA held a summit in Minneapolis for its “Every Day Counts” (EDC) innovation initiative. EDC is designed to identify and deploy innovation to shorten project delivery, enhance roadway safety, and protect the environment.
FHWA teams will work with state, local, and industry partners to deploy innovations and develop performance measures to gauge their success. Minnesota LTAP will take part in these efforts, says director Jim Grothaus, who attended the summit.
Innovations considered under the program include the Safety Edge, flexibilities in right-of-way and utility accommodation, and design-build.
More information about Every Day Counts
The University of Minnesota Stormwater Education Program works with many organizations to help protect water quality. The program promotes innovative stormwater best management practices among stormwater practitioners—contractors, developers, engineers, and field staff—through locally tailored workshops known as Stormwater U.
The program’s Web site includes workshop information; links to programs, manuals, and other references for stormwater professionals; and pond sediment excavation best practices.
A new manual from the University of Minnesota’s St. Anthony Falls Lab—Stormwater Treatment: Assessment and Maintenance—helps users assess the performance of, and schedule maintenance for, stormwater treatment practices.
University of Minnesota researchers analyzed data from two Mn/DOT soil surveys: the Metro 2001 Soil Survey, which looked at how chemicals in the soil change with the distance from major highways, and the Statewide 2003 Soil Survey, which explored the patterns of chemical clustering based on statewide geomorphologic units and the source of glacial sediments. Their report could help in choosing materials for roadway beds or fill-in.
Final report on the project: Statistical Analysis of the Soil Chemical Survey Data (Mn/DOT 2010-22)
Barriers to Implementing Low-Impact Development Approaches in Washington State Roadways and Highways explores barriers to implementing low-impact-development (LID) stormwater management approaches and provides recommendations on how the Washington State Department of Transportation can overcome them. LID is an approach to stormwater management that seeks to mimic the natural hydrologic functions of stormwater runoff prior to development.
A report by the Virginia Transportation Research Council—Evaluation of Environmental Impacts of Two Common Restoration Methodologies for Pipes that Convey Stormwater Runoff—examines the environmental impact of chemicals that leach from synthetic pipe liner material into water flowing through the repaired pipe.
Sustainability in transportation was the focus of the fourth TERRA Innovation Series event held August 20 in Madison, Wisconsin. Participants learned about evolving strategies to reuse and recycle materials as part of asphalt and concrete road projects, such as recovering asphalt from recycled shingles and using fly ash to stabilize bases. These approaches can provide environmental benefits as well as cost-savings.
Read the full article in the October 2010 TERRA E-News.
More about the Transportation Engineering Road Research Alliance
The FHWA Office of Planning has completed the Livability in Transportation Guidebook: Planning Approaches that Promote Livability. The primary purpose of the guidebook is to illustrate how livability principles have been incorporated into transportation planning, programming, and project design, using examples from state, regional, and local sponsors. It is intended to be useful to a diverse audience of transportation agency staff, partners, decision makers, and the general public, and is applicable in urban, suburban, and rural areas.
View the guidebook along with other resources on livability.
The National Association of Counties released a publication highlighting county sustainability efforts in 2010. The publication will assist counties to better define, prioritize, and more fully assess their sustainability efforts.
Download the publication (3.8 MB PDF).
A paper from the Asphalt Pavement Alliance—Carbon Footprint: How Does Asphalt Stack Up? (1.8 MB PDF)—examines the greenhouse gas production of asphalt and concrete pavements throughout their life cycles.
Researchers in the Netherlands have tested pollution-eating concrete on about 1,000 square meters of roads. The results: a 25% to 45% reduction in oxides of nitrogen (NOx) over the special roads. Read more.
The Center for Technology and Training at the Michigan Tech Transportation Institute has created a narrated presentation to help local agencies begin the discussion of sign retroreflectivity with decision makers. This Web-based informational presentation explains the science of retroreflectivity, the new federal requirements, and the MUTCD methods.
More about The New National Standard for Maintaining Minimum Sign Retroreflectivity
The FHWA’s Sign Retroreflectivity Guidebook, developed in 2009, is available for download from Mn/DOT State Aid’s Web site. An interactive online version of the guidebook is also available. In addition, the LRRB funded the development of a supporting document: Sign Retroreflectivity—a Minnesota Toolkit. It includes MnMUTCD requirements and a summary of the FHWA guidelines.
Another resource—Minnesota’s Best Practices for Traffic Sign Maintenance and Management—includes information about retroreflectivity. The handbook was developed for a Minnesota LTAP workshop.
To comply with federal retroreflectivity rules, the City of Stillwater, Minnesota, is replacing its signs. But instead of recycling the old signs, it is selling them for $10 apiece.
Read the article in the November 6 Minneapolis Star Tribune.
The National Center for Wood Transportation Structures has a new site: www.WoodCenter.org.
The site was established through a collaboration between the Forest Products Laboratory and Iowa State University. The site’s search and browsing features provide access to a wealth of wood transportation knowledge, including research in progress and demonstrations in progress.
Additionally, a Wood Structures Reference Library has been established and is housed at the National Center for Wood Transportation Structures (NCWTS) at Iowa State University. This library comprises both print and electronic materials and is fully searchable on the website.
A new report—Smart Mobility for a 21st Century America (1.3 MB PDF)—demonstrates how existing and emerging technologies can increase capacity on congested highways, help commuters avoid traffic delays, and expand and improve transportation options while saving money and creating jobs. The report was authored by Transportation for America, the Intelligent Transportation Society of America, the Association for Commuter Transportation, and the University of Michigan SMART Initiative.
The impact of intelligent transportation systems (ITS) technology on driver privacy, how school choice affects the environment, and how the Internet influences shopping travel are several topics explored in a recently released report by the Humphrey Institute of Public Affairs’s TechPlan Program. TechPlan: Planning and Policy for Intelligent Transportation Systems discusses work to date on projects that have the potential to address long-term issues in transportation policy. TechPlan is a program housed within the University of Minnesota’s Humphrey Institute’s State and Local Policy Program (SLPP) and funded by SAFETEA-LU through the ITS Institute.
An updated version of the National Transportation Training Resource (NTTR) is now available. The NTTR is an online database of information about learning resources for the public-sector transportation workforce and a tool for training managers and frontline transportation professionals. Training managers can use the NTTR to obtain information about courses already developed and resource developers, while professionals can use the NTTR to locate opportunities to build their knowledge, skills, and abilities.
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