Speeding is one of the top 5 factors in crashes in Minnesota. Prioritizing the most effective methods to encourage safe speeds is critical to maximizing effort and funding to reach zero deaths on our roadways.
In 2019, legislation passed to allow Minnesota cities to establish speed limits for city streets under the city’s jurisdiction without conducting an engineering or traffic investigation.
Continue reading New Project: Impact of Speed Limit Changes on Urban StreetsIn Minnesota, reducing the effects of oxidation is a continuous challenge.
In a new study, funded by the Local Road Research Board, researchers will compare the effectiveness of two different methods: applying a surface treatment (typically a fog or chip seal) and increasing the asphalt film thickness during original construction.
Continue reading New Project: Benefit/Cost of Applying a Higher Asphalt Film Thickness vs. Doing a Chip Seal at One YearComplete Streets is a transportation policy and design approach that requires streets to be planned, designed, operated, and maintained to enable safe, convenient, and comfortable travel and access for users of all ages and abilities regardless of their mode of transportation.
Continue reading New Project: Assessing the Economic Effects of Context Sensitive Main Street Highways in Small CitiesMnDOT has successfully piloted a European knowledge retention method to preserve the expertise of retiring workers who are subject matter experts. The agency has produced interactive multimedia books that use graphics, video and written material to present valuable information on concrete pavements, asphalt pavements and steel bridges, learned over a person’s entire career, for use by future engineers.
Continue reading Knowledge Books Preserve Expertise of Retiring Workers
Roadside dynamic message signs with breakaway components handle wind-induced vibrations adequately for an almost 24-year fatigue life. Rural intersection conflict warning signs vibrate noticeably under wind forces and require design changes to resist fatigue damage.
These are the results of a new research study sponsored by the Minnesota Department of Transportation that investigated the effects of wind loading on roadside message and conflict warning signs.
Continue reading Wind Impact and Breakaway Performance of Roadside Message and Conflict Warning SignsA new guidebook published by the Minnesota Local Road Research Board offers a uniform approach and practical methods for selecting locations and the right treatment for uncontrolled pedestrian crosswalks in Minnesota.
Continue reading Selecting Uncontrolled Pedestrian Crosswalk Treatments
MnDOT construction projects require tons of hot mix asphalt each year, with over 188 road and bridge projects in the 2020 construction season alone.
Historically, plant mixed asphalt has been weighed, tracked and paid for with computer-generated paper tickets. Paper ticketing isn’t an ideal process for a variety of reasons—on-site ticket collection poses safety risks, tickets can be easily lost, and data must be tabulated manually, just to name a few.
Continue reading Asphalt Delivery Tracking Goes Digital with Some 2020 Construction ProjectsCities and counties need affordable pavement preservation treatments, but preservation strategies are often geared towards higher-volume roads. The Minnesota Local Road Research Board has developed new guidance on five lower-cost treatments that is more applicable to local agencies and can be used to preserve pavements based on the type and severity of pavement distress.
Continue reading Pavement Preservation Techniques for Local AgenciesReinforced concrete bridges are built to handle heavy loads and routine traffic for 75 years or more. But bridges in climates like Minnesota’s are exposed to moisture and chlorides from road salts that may penetrate these structures and corrode the steel.
In a recently completed research project, funded by MnDOT and the Local Road Research Board, researchers studied a rural bridge built in 2017 near Elgin, MN, that used glass fiber–reinforced polymer (GFRP) rebar in the bridge deck. They found that GFRP performed well, proving sufficiently strong for use as an alternative to corrosion-susceptible steel rebar.
Continue reading GFRP Rebar Shows Promise for Use in Bridge DecksJust in time for spring, new guidance is available from the Minnesota Local Research Board on the best irrigation methods to establish fresh turfgrass. Researchers tested five irrigation methods for watering new installations of salt-tolerant turfgrass. They developed an instructional course for contractors and guidance for homeowners to promote successful turfgrass installation.
Continue reading Improving Roadside Turfgrass Establishment
