Roadside improvement

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.

This flyer pertains to report 2019RIC09, Best Practices for Boulevard Turf Design and Maintenance.

This Technical Summary pertains to Report 2023-20, “Turfgrass Seed Variety Evaluation Process,” published June 2023.

Our project addresses two critical needs: to update existing MnDOT turfgrass recommendation lists and to develop a new process to keep lists continually updated in a fair manner with data-driven recommendations. We evaluated the current list of MnDOT-approved turfgrass varieties and found underperforming varieties that should be removed. We then found new, improved varieties that should be considered for inclusion on the MnDOT lists. To facilitate a process to keep lists updated for the future, we first conducted a survey of seed distributors. Using their input, we developed a new process that MnDOT can use to approve turfgrass varieties for inclusion as official seed mixtures. Ultimately, this will lead to a more nimble, consistent, and clear process so that existing and new seed vendors can have complete confidence in data-driven decision making by MnDOT.

This report details a project to study the relationship between highway design and human behavior as influenced by roadside environments. In a visualization phase, computer simulation modeled an actual segment of urban highway planned for reconstruction in Tofte, Minn. Using a driving simulator, project design team members test drove the highway reconstruction project and evaluated the planned elements. In an experimentation phase, researchers tested drivers' responses to different design scenarios to identify the architectural and aesthetic elements with the greatest potential for calming or slowing traffic. Results indicated that the visualization phase increased communication among project team members and state agencies, facilitated problem identification-resolution strategy development, and contributed to decision making concerning potential design options and design elements. Data also indicated that white pavement treatments produced desirable traffic calming effects. Analyses of drivers' speed patterns indicated a consistent speed profile, characterized by both decreases and increases in speed. The report concludes with recommendations for the expanded use of visualization in general, and the implementation of white pavement treatments in the target reconstruction project specifically. It also recommends further consideration of landscape architecture treatments

In this project, researchers used extensive laboratory, greenhouse, and field studies to determine the relative salt tolerance of select native grasses and forbs used to re-vegetate rights-of-ways within four meters of the pavement edge. The studies found that grasses prove relatively tolerant to salt, but show poor survivability in the field during over-wintering. In contrast, forbs generally are sensitive to salt in their environment. Planting success of monocultures and mixtures of grasses near the pavement edge was poor. Observed percent coverage after two years ranged from about 10 to 20 percent over all tested species. Monitoring of longer established sites also shows that native species do not increase as a stand ages. Soil amendments including gypsum, potash, and potassium nitrate were only minimally effective in alleviating salt stress in sodic soils, although gypsum may have some promise in further field testing. The application of salt during winter salting operations also permanently and negatively impacts soil chemistry, which in concert with other plant stress factors such as soil compaction and infertile roadside soils, will continue to limit the success of establishing desirable vegetation on the inslopes of heavily salted roadways in Minnesota.

The Minnesota Department of Transportation (Mn/DOT) has been active in developing the best technology for roadside vegetation control. One method, herbicide spraying, helps eliminate unwanted vegetation. Treatment of unwanted weeds often requires the use of different herbicides. Sprayers must have the capacity to spray more than one chemical at a time, negotiate rough terrains, and apply herbicides safely and in a way that preserves the environment. This report presents the results from testing and evaluating four automated sprayers: The B&B Ditch Sprayer 300 Prototype, a Wanner Innovative Sprayer, the Micro-Track Spray System, and the SCS 750. All four tested sprayers are more economically feasible than the traditional sprayer. The B&B Ditch Sprayer has the lowest net annual savings of the four tested sprayers. The Wanner Sprayer is more economical for use in large districts or in areas with extensive road miles. The Micro-Track Sprayer has the highest rate of return, and also reduces annual costs. The SCS Sprayer has the highest net annual savings and also can monitor, tabulate, and print all vital statistics. The report details product features, testing, and results.

Note: Some corrections/changes have been made in this supplement (November 1, 2006; August 26, 2008). In 2002-2004 the Minnesota Department of Transportation (Mn/DOT), working through its consultant Gemini Research, conducted a cultural resources survey and evaluation of eight properties to be added to Mn/DOT's Historic Roadside Development Structures Inventory. The addition of the eight brings the total inventory to 110 properties. Gemini Research recommends that three of the eight newly-inventoried properties are eligible for the National Register of Historic Places. This document, intended as a supplement to the 1998 inventory report Historic Roadside Development Structures on Minnesota Trunk Highways, adds the eight new properties to the inventory, updates key inventory information, and corrects selected errors in the original inventory. The updated information lists, for example, the historic preservation treatment reports that Mn/DOT has prepared for National Register-eligible and -listed sites. The report also briefly discusses serious threats facing the inventory sites including their deteriorating physical condition.

A cultural resources study of historic roadside development properties was conducted in 1996-1998 by Gemini Research for the Minnesota Department of Transportation (Mn/DOT). The study's goal was to inventory all roadside development properties on current Mn/DOT right-of-way that contain pre-1961 standing structures and to evaluate the National Register eligibility of the sites. A total of 102 properties were inventoried. Eleven of the properties are listed on the National Register or located within a National Register historic district. The study recommends that 51 individual properties and 1 historic district containing 7 properties meet the registration requirements of the historic context entitled "Roadside Development on Minnesota Trunk Highways, 1920-1960" and are therefore eligible for the National Register under this context. A set of 102 inventory files and this final report are included among the study's final products.

A study was performed to assess the use of perennial native grasses in the control of leafy spurge and Canada thistle and also to evaluate the effects of herbicides applied during the fall to leafy spurge crown buds. As part of an integrated vegetation management program, grass treatments containing the native prairie grass little bluestem established well and were effective at reducing the cover of leafy spurge. Paramount to the success of using native grass species is getting adequate grass establishment which necessitates the careful selection of grass species adapted to the specific site conditions. A fall application of the herbicide picloram at 0.5 and 1.0 lb ai/acre was very effective at controlling leafy spurge and may be mediated via the direct absorption of picloram by the elongated crown buds at this time. The report contains an extensive literature review of the biology and weed control efforts of both leafy spurge and Canada thistle.