LRRB Welcomes New Chair and Members

The Local Road Research Board thanks Tim Stahl (Jackson County), pictured far left, and Lyndon Robjent (Carver County), third from left, who recently completed two, four-year terms of service. Jim Foldesi (St. Louis County), far right, replaces Robjent as chair. The board welcomes new members Lon Aune (Marshall County) and Wayne Sandberg (Washington County), not pictured. Also pictured is Kristine Elwood, State Aid Engineer.

Kuehl Recognized For Transportation Safety Work

Minnesota Toward Zero Deaths has awarded its annual Engineering Star Award to Renae Kuehl, LRRB research implementation and outreach consultant, in recognition of her work on safety-related initiatives such as the Statewide County Road Safety Plans, which draw on the findings of LRRB research. “These efforts make Renae a key person involved in reducing the number of traffic-related fatalities on Minnesota's roads,” the awards committee stated.  

Asset Management Guide Addresses Needs of Local Agencies

The Minnesota Local Road Research Board has published a new guidebook to help local agencies get started on developing a consolidated asset management system. The guide addresses the particular needs of smaller groups to effectively and optimally manage their roadways, buildings, vehicles, equipment and other assets.

For the guidebook, interactive guidebook, and technical summary, visit the Local Road Research Board.

Design Standards for Unobstructed
Sight Lines at Left-Turn Lanes

Positive offset left-turn lanes can significantly reduce crashes by improving left-turning motorists’ visibility of opposing through and right-turning traffic. These are the findings of a new study, which examined decades of research and reviewed guidance from 23 state DOT road design manuals to develop Minnesota-specific guidelines to improve sight lines at intersections, particularly those of left-turn lanes. The recommendations will be incorporated into the revised version of MnDOT’s Road Design Manual.

For more information, visit the research project page.

Taconite-Based Mixture Shows Further
Promise for Repairing Potholes

Researchers have further refined a quick and innovative pothole repair method using taconite mixtures.

The recently completed study was funded by the Minnesota Local Road Research Board in collaboration with MnDOT, the City of Duluth, and the Duluth International Airport. Researchers evaluated the performance of taconite repairs completed in 2018-2019 and developed a new two-ingredient mixture. The mixture shows promise as a cost-competitive, long-term solution for potholes.

For more information, visit the research project page.

Optimized Sight Distances at Rural Intersections

Using a sophisticated driving simulator, researchers determined that 400 and 600 feet of sight distance is insufficient at rural intersections. Drivers performed much better with 1,000 feet of sight distance, both at intersections and on main line roads responding to vehicles running stop signs. Researchers also noted that moving the stop bar closer to the main line at thru-stops would both increase the sight distance of waiting drivers and influence the main line drivers to slow down when approaching intersections. Safety could be increased with this very low-cost change.

For more information, visit the research project page.

LRRB Sneak Preview at Minnesota's Transportation Conference

The LRRB is hosting Session #22 on Wednesday, March 4, 2020 from 10:00 - 11:00 a.m. in Meeting Rooms 2-3 at the Saint Paul RiverCentre. Make sure to check it out!

The LRRB is the envy of many states. Having dedicated funding that specifically focuses on research and innovation for city streets and county roads truly sets Minnesota apart. In this session you will hear about:

• a project that recently won a National award from APWA on how to positively addressing citizens’ common requests for traffic safety concerns without just saying “no.”
• a paradigm shift from traditional roadway design to 3D and 4D modeling, including Civil Integrated Management (CIM).
• a sneak preview of an online tool to help cities and counties “Raise the Grade” via asset management.

To register and view the full conference agenda, visit the University of Minnesota.

Civil Engineering Day at the Science Museum

The roads you drive on, the bridges you cross, the buildings where you study and work — they’re all possible because of civil engineering!

Meet local engineers, tinker and explore STEM projects and ideas, and get inspired at Civil Engineering Day on February 29 at the Science Museum of Minnesota. You’ll be immersed in the power of engineering with hands-on activities that celebrate the work civil engineers do to solve problems and improve lives every day. Civil Engineering Day festivities are included in regular museum admission.

Get STEM-inspired and find out more at the Science Museum.

Roads & Bridges: Structural Fiber Choice for Thin Concrete Pavements Can Have a Significant Impact on Quality

A recently completed research project, funded by the LRRB and MnDOT, is featured in the January 2020 edition of Roads & Bridges.

In today’s dwindling budgeting scenario, state DOTs strive for long-lasting pavement rehabilitation alternatives that require less in future maintenance dollars. Tiny bits of fiber have been making a big difference in concrete pavements.

Researchers tested the use of structural fibers in thin concrete overlays—specifically looking at the fiber's ability to keep cracks from widening. Researchers studied the ideal mixture rates and tested procedure recommendations for future projects using fibers.

2019 Research At-A-Glance

The 2019 At-A-Glance (pdf) for the Minnesota Local Road Research Board is now available. It serves as quick-reference guides to the state and local research programs—including project highlights, an overview of the research process, and information about our transportation research synthesis program.

Visit the Local Road Research Board to access the current and previous years' reports.