All posts by mndotresearch

Investigating Asphalt Pavement Stripping Under Seal Coats

A recent Local Road Research Board (LRRB) study confirmed that increased freeze-thaw activity during Minnesota winters leads to delamination of seal coats from underlying pavements. Researchers identified optimal seal coat mix combinations and site conditions that may ensure effective seal coating of asphalt pavements in cities and counties around Minnesota. 

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Local Guidance for Bicycle Facility Design

A quick reference guide is now available to help local agency planners and designers select the best bicycling facilities for their system. This guide walks local agencies through the selection and design process, and directs users to specific places within design manuals for details on facility questions.

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Smartphone App Gives Crossing Guidance to the Visually Impaired

In a recent research project, MnDOT sought to validate a smartphone app designed to guide pedestrians who are blind or visually impaired through signalized and unsignalized intersections. The project succeeded in showing the app’s effectiveness in tests at six intersections in Stillwater, Minnesota.

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Low-Volume Road Runoff Analyses Suggest Optimal Treatments

Assisted by many county agency staff, researchers collected and analyzed runoff from low-volume rural roads over two years to determine how their contaminants compared to those of high-volume roadways. Results documented that runoff from low-volume roads has a lower contaminant concentration and that ditches and swales can be used to effectively treat rural road runoff.

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Understanding Rural Pedestrian Travel Behavior and Safety Issues

In collaboration with the Advocacy Council for Tribal Transportation and other tribal members, University of Minnesota researchers monitored 10 roadway sites specified as safety risks for pedestrians on four rural Minnesota reservations. Analysis of videos and group brainstorming produced a shortlist of potential countermeasures that could be incorporated into future highway projects.

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Monitoring Performance of an Iron-Enhanced Stormwater Filtration System

A recent study determined the effectiveness of a two-cell iron-enhanced stormwater filtration basin to remove phosphorus from highway stormwater runoff collected from 2012 to 2018. Researchers recommended design changes that would allow for more accurate monitoring of these filter basins.

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Richfield “Sweet Streets” Improve Quality of Life, Traffic Times Citywide

Complete streets is an approach to road planning and design that considers and balances the needs of all transportation users.

Richfield, Minnesota, located south of Minneapolis, began a Complete Streets redesign in 2013. So how did it turn out? A retrospective study has found that while construction impacts remain on the minds of business owners and residents, Richfield’s program has improved community life and traffic times citywide. Safety and multimodal use are expected to improve.

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How Well Do Stop Lines Work as a Safety Feature?

How well do the stop lines at stop-controlled intersections actually work as a safety feature? Through an extensive safety study and a before-after field observation, a recent Minnesota Local Road Research Board study showed that the assumed safety effects of stop lines as a means of influencing driver behavior are not well supported by the evidence.

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