MnDOT and Local Road Research Board

This Technical Summary pertains to Report 2022-31, “Establishing a Repeatable Method for Presenting Non-Traditional Traffic Treatments to Maximize Stakeholder Support,” published June 2023

A novel infrastructure design known as the J-turn intersection reduces the risk of serious and fatal crashes at thru-STOP intersections through decreasing points of conflict at an intersection by restricting crossing movements from the minor road. Despite their demonstrated safety efficacy, J-turns have not been met with uniformly positive support. In this research, we first examine novice driver baseline attitudes and driving behaviors on J-turns using a driving simulator study. Results demonstrate that critical errors are decreased with driving exposure to the J-turn; however, attitudes toward J-turns are not improved by exposure alone. A series of studies then evaluates the efficacy of various messaging strategies and educational materials on improving attitudes toward J-turns. The findings from these studies identify that the use of both educational materials and persuasive and customized messaging strategies is an effective method for increasing acceptance of J-turns across diverse resident populations (i.e., rural, suburban, and urban) and among stakeholders in Minnesota. This work demonstrates the importance of the role of proactive educational programs and community initiatives in promoting the acceptance and buy-in toward novel roadway treatments, such as J-turns, among diverse drivers, communities, and stakeholder groups.

This report analyzes how state-funded highway improvement projects in the seven county Twin Cities metropolitan area affected businesses in adjacent Census Tracts. We first identify demographic factors associated with the temporal and financial prioritization of some projects over others, finding that the per capita income of a Census Tract is associated with it featuring more heavily prioritized highway improvement construction. We then turn to the effects of highway improvement construction and operation, using results from the previous analysis to account for endogeneity of improvement timing. While we find largely null results of highway improvement on sales, employment, establishment counts, and turnover for both single-establishment and multiple-establishment firms, we also find that pooling data masks several sources of effect heterogeneity. Specifically, we find that single-establishment firms experience negative sales effects from construction when tracts are affected only by infrastructure replacement projects (improvements that do not affect traffic operations, i.e., a bridge replacement). Furthermore, negative sales and employment effects occur after construction is completed for single-establishment firms in urban areas and in tracts affected by longer bouts of construction. Meanwhile, in suburban areas, some modest gains accrue to multiple-establishment firms. These results suggest that regional planners need to account for potential externalities from highway construction on particularly nearby small business establishments

MnDOT evaluated five pieces of new winter maintenance equipment: two slurry spreaders, an underbody scraper, a true-float wing plow and a two-way reversible plow. For Winter 1 of the evaluation program, all equipment was acquired, installed, and field-tested in MnDOT District 2. For Winter 2, a data collection program was developed to capture quantitative data on how well the equipment worked in District 2, compared side by side against comparable routes with traditional spreaders. Winter 1 and 2 field testing of the three types of plow equipment allowed operators to fix operational problems and led participants to agree that MnDOT should continue to use such equipment and acquire more. MnDOT participants did not reach consensus on whether to continue to use or buy more of the two slurry spreaders. Data analysis showed that they performed comparably to traditional slurry spreaders in terms of road regain time and salt use when they were operational. Issues included equipment height, causing loading and maintenance worker safety concerns; equipment weight, reducing how much material could be loaded in the truck; difficulty in setup; equipment not operating as expected; and difficulty obtaining vendor parts and getting vendor support. These issues led to the cancellation of a third winter of testing in a different district. It was suggested that the equipment might better suit MnDOT’s needs by mounting it on a boxless truck.

This Technical Summary pertains to Report 2023-29, “Identifying and Optimizing Electric Vehicle Corridor Charging Infrastructure for Medium- and Heavy-Duty Trucks,” published June 2023.

This Technical Summary pertains to Report 2023-26, “User-Centered Smart Traffic Sign Development Study,” published June 2023.

This letter example pertains to report 2019-42G, A Guide to Successfully Convert Severely Distressed Paved Roads to Engineered Unpaved Roads, and also appears in Appendix G of this report.

This fact sheet pertains to report 2019-42G, A Guide to Successfully Convert Severely Distressed Paved Roads to Engineered Unpaved Roads, and also appears in Appendix G of this report.

The checklist and forms pertain to report 2019-42G, A Guide to Successfully Convert Severely Distressed Paved Roads to Engineered Unpaved Roads, and they also appear in Appendix A of this report.

Please note this manual also appears as Appendix B within report 2017-11, An Innovative Approach to Smarter Mowing, Utilizing Automated Vehicle Location to Enhance Mowing Operations.