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The use of lightweight fill is increasing in the state of Minnesota. This material is used to replace a heavier insitu soil so as to reduce the load burden on the subgrade. There may be several alternative materials to consider for any construction project; however, design engineers might not consider them because of a limited knowledge or unfamiliarity with them. Various materials have been used, but specific design guidelines are not available because this type of construction is still considered experimental. The current selection is generally based on local knowledge. Additional research is required to determine more specific design guidelines for each lightweight fill material. The Local Road Research Board (LRRB) has therefore requested this synthesis to determine what technology and materials are available for the appropriate use of lightweight fill material in road construction.

As a supplement to the rural mailboxes brochure, the following information was provided by the City of Eagan as an example to provide guidance for urban mailbox installation. The city developed the following documents to educate the city council and residents on the need for proper mailbox installation: - Standard Plate – Mail and Paper box installation guidelines - Memo to Mayor and City Councilmembers – Summary of need to standardize mailboxes to reduce damage due to winter maintenance. - Resident notice flyer – sent to residents with non-complying mailboxes notifying them of the need to modify their mailbox to avoid damage due to winter maintenance.

This presentation was created to accompany Report 2016-34A, System Preservation Guide: A Planning Process for Local Government Management of Transportation Networks, published in 2016.

This report highlights the findings of a project to determine the impact of traffic calming strategies on driver behavior, traffic flow, and speed. Researchers used a number of different approaches, including a literature search to determine results at a national level and local before-and-after studies in areas that implemented new traffic calming strategies. Researchers also compared an actual street before and after implementation of traffic calming devices to a driver simulation study of a street with and without traffic calming devices. Research results indicate that traffic calming can have a limited impact on average driver speed. The greatest impacts on speed often occur in reducing the number and speed of outliers, or those who travel at speeds greater than the 85th percentile speed. The report details the impact of different types of traffic calming strategies on traffic speed and volume.

This report describes the results of studies on the use and effectiveness of rumble strips, including a survey of Minnesota county engineers and a simulation conducted at the University of Minnesota Human Factors Laboratory. Sixty-eight of 87 counties responded to the survey. Of the 68 respondents, 56 install in-lane rumble strips. The survey also asked respondents to describe the guidelines that they used to designate areas for rumble strip installation. As part of the simulation study, test subjects drove in a simulator through a designed experiment to measure the effectiveness of in-lane rumble strips. The results of this study showed different braking patterns between intersections with in-lane rumble strips and those without rumble strips. Those with rumble strips braked earlier and harder. The report recommends that shoulder rumble strips be used in areas with high rates of run-off road crashes. Before-and-after studies have shown conclusively that shoulder rumble strips have reduced run-off road crashes by 20% to 72%. It also recommends a follow-up study on in-lane rumble strips involving drivers that are sleep deprived, under the influence of alcohol, or driving in poor conditions.

This report was produced for the Local Road Research Board (LRRB) and provides a summary of the use of recycled asphalt pavement within Minnesota. Included in this report is: (1) A synthesis of a manual produced by the Asphalt Recycling and Reclaiming Association (ARRA) and endorsed by the Federal Highway Administration (FHWA) titled the Basic Asphalt Recycling Manual (BARM). The BARM provides a complete summary of various recycling techniques and the process for conducting a recycling project. (2) A Summary of a survey that was distributed to cities and counties throughout Minnesota. This survey was distributed to gather input on the amount of asphalt recycling done in Minnesota. Survey results are discussed throughout the report with a complete overview in the report appendix.

Oftentimes roadway projects, whether new construction, reconstruction, or maintenance of an existing facility, involve either temporarily or permanently relocating utilities within the project area. Ensuring that utility relocation is done in a timely manner requires coordination not only by the utility companies, but by the local government planning the roadway project, and, oftentimes, by the contractor chosen to conduct the roadway work. Lack of effective coordination can result in costly delays and aggravation to the traveling public. This report summarizes a review of recent efforts to facilitate the process of utility relocation as part of roadway construction, identifies coordination resources, presents the findings of a survey administered to county and city engineers, utility companies, and construction contractors, and provides recommendations and materials to make the process of utility relocation at the county and city level in Minnesota more efficient and effective.

This manual describes the evaluation and design procedures for pavement rehabilitation. The evaluation emphasizes a number of variables or conditions that should be considered. This manual does not introduce any new technology. Thickness designs of new pavements require two primary variable: traffic and soil strength. Rehabilitation design requires several additional variables such as: pavement structure, condition and strength. Rehabilitation design can involve more alternatives than new design that deal with materials, equipment, disruption of traffic and work zone safety. This manual has been written as a working reference to help identify and classify the surface distress, explore the various rehabilitation alternatives, select an appropriate alternative and briefly describe the rehabilitation procedure. The manual provides standardized identification of distress types for both flexible and rigid pavements, calculation procedures for Equivalent Axle Loads, and a brief synopsis of the AASHTO thickness design procedure. This manual should be used by cities and counties as a reference in developing rehabilitation strategies

The MnDOT Bridge Office sought out information on best practices regarding the use of drainage systems on bridges. Minnesota regulations strongly discourage the discharge of runoff directly into waterways; however, bridge drainage systems can lead to accelerated deterioration in bridge elements. MnDOT requested a synthesis to gather information to assist them in future development of guidance on design, detailing, specifications, construction, and maintenance procedures for bridge needs, focusing specifically on agencies with similar northern climates to the greatest extent possible.

Recent initiatives at the state and federal level have focused attention on possible ways of streamlining or expediting the project delivery process. While some of these efforts have focused on methods and practices to speed planning and pre-construction activities, the purpose of this investigation was to examine means of speeding the roadway and highway construction cycle. Highway construction time has very real costs to all parties involved in the process; highway departments, contractors, and most especially the public whose tax dollars and time is spent waiting for projects to be completed. Recognizing this, the Local Road Research Board's (LRRB) Research Implementation Committee (RIC) began this investigation to explore current activities, techniques and materials whose use reduces construction time, and to determine the extent of their use by city and county engineers in Minnesota.