This report summarizes lessons learned about the field performance of local roads containing Recycled Asphalt
Pavement (RAP) and associated field and laboratory work with asphalt activation as well as the design and
performance testing of high-RAP bituminous mixtures.
Developing Twin Cities Arterial Mobility Performance Measures Using GPS Speed Data
The overall goal of this study was to use commercially-available travel speed data to develop arterial street mobility performance measures in the eight-county Twin Cities Metropolitan Area. The research team licensed 2011 historical traffic speed data from INRIX for 1,604 directional-miles of arterial streets, and conflated this speed data with MnDOT traffic volume data on the same street network. Based on prevailing practice, TTI recommended travel speed-based mobility performance measures that compare peak traffic speeds to speeds during light daytime traffic. However, it was recognized that light daytime traffic speeds are not necessarily the goal or target for the performance measures, but simply a convenient and easily-measured reference point. Instead, performance measure target values should be context-sensitive and based upon surrounding land use. Multiple measures should be used to quantify and monitor mobility on arterial streets, including delay per mile, travel time index, and the planning time index (a measure of reliability). The exact mobility performance measures and target values are likely to evolve and be refined as MnDOT and partner agencies gain experience in performance monitoring on arterial streets. At this time, TTI recommends calculating, tracking, and gaining experience with multiple measures, while also determining where these measures can be used to improve agency decisions.
Mitigating Highway Construction Impacts Through the Use of Transit
Traveling habits form patterns in cities over time. During construction these patterns are disrupted causing much aggravation. MnDOT and the Duluth Transit Authority (DTA) used the Duluth Megaproject highway construction to entice travelers to utilize other transit options. Surveys found that all efforts put forth helped attract riders to transit and sustain these transit patterns even after construction was complete.
Development of a Concrete Maturity Test Protocol
An extensive field and laboratory project was undertaken to evaluate the applicability for using the concrete
maturity method to predict opening to traffic criteria for portland cement concrete paving operations in Minnesota.
The field study included visits to18 paving projects in the state over a three-year period. At these projects, different
sensor types were evaluated. In the laboratory study, two-inch mortar cubes were tested to develop sensitivity
analyses related to the proportions of cementitious materials, water-cementitious materials ratio, and other mix
2013-09 Synthesis of Bridge Approach
Panels Best Practices
This research project was primarily a synthesis study of other states' practices for
the expansion joint.
A detailed study of the following agencies' practices was conducted: Wisconsin, South Dakota, Iowa, Michigan,
Ohio, Kansas, and Ontario, Canada. There were substantial differences between all of the practices and none easily
adaptable to Minnesota. For instance, Minnesota, unlike the other states studied, does not permit deck drains on its
bridges for environmental reasons. Most of the agencies seemed satisfied with their current practices. Four out of
the seven agencies used strip seals in one form or another. Only one (Iowa) still uses the same foam filler as
Minnesota, although others had in the past. The Iowa detail involves doweled bars across the joint and a different
approach slab detail.
Stripping of Hot-Mix Asphalt
Pavements under Chip Seals
The higher costs of hot-mix asphalt pavement are causing more agencies to choose pavement preservation
techniques to maintain their pavements. Some agencies have experienced stripping of the asphalt surface under
chip seals, this distress appears to occur mostly in urban areas on curb and gutter streets. The main objective of the
study was to determine what causes the stripping and to develop test methods to determine if the street will strip
prior to placement of the chip seal. Both field and lab methods were used. Research focused on determining air
voids, permeability, and density of the samples. Once these were determined, correlations were developed to
determine the conclusions.
Understanding the Economic Effects of Flexibility through Three Employer Case Studies
Market research conducted through the Urban Partnership Agreement (UPA) project on telework shows
that employers need to be convinced of the economic benefits of telework before they will embrace such
a policy. If telework is to gain widespread support in government and industry, employers need to be
presented with strong evidence that telework is good for their bottom line and industry productivity.
It is not clear that previous research has documented the impacts of telework from an employer
perspective. This research project proposes to investigate what are the bottom line (and economic)
advantages to employers of telework policies in order to fill this gap in the literature and to provide
evidence to employers considering telework policies.
Research Implementation of the SMART-SIGNAL system on Trunk Highway (TH) 13
Investigators upgraded the SMART-SIGNAL (Systematic Monitoring of Arterial Road Traffic and Signals) system by making field hardware more compact and easier to install. They also developed a Web-based interface for traffic control center software, allowing the generation of real-time arterial performance measures and historical statistical reports. Investigators implemented the refined system at 13 intersections along Trunk Highway 13 in Burnsville, Minnesota.
Quality of Life: Assessment for Transportation Performance Measures
Quality of life (QOL) is a commonly used term. Defining QOL, however, is an ongoing challenge that experts often take on with minimal input from citizens. This groundbreaking research sought citizen input on what comprised QOL and what role transportation played in it. Further, this research explored in detail the important factors across the breadth of transportation and how the Minnesota Department of Transportation (MnDOT) was performing on these important factors. The research encompassed three phases between 2010 and 2011: (1) an extensive literature review on QOL, (2) 24 focus groups that asked Minnesota¿s citizens about their QOL, and (3) a mail questionnaire about what matters in quality of life, transportation and their intersection. Eleven related quality of life factors emerged, including transportation: education, employment and finances, environment, housing, family, friends and neighbors, health, local amenities, recreation and entertainment, safety, spirituality/faith/ serenity, and transportation.
Investigators installed 55 energy-efficient streetlights along a section of 46th Street in south Minneapolis. This project evaluated the cost-effectiveness and lighting quality of both LED and induction light technologies, and compared products from several manufacturers and vendors. LED streetlights were found to provide adequate lighting quality. This technology may soon be cost-effective for general use.
2013-03 Case Studies of Transportation Investment to Identify the Impacts on the Local and State Economy
This project provides case studies of the impact of transportation investments on local economies. We use multiple approaches to measure impacts since the effects of transportation projects can vary according to the size of a project and the size of the area under study, as well as other exogenous factors such as existing economic and demographic conditions. We measure effects on economic output and employment to estimate impacts of specific investments, and address issues of generative versus redistributive effects of investments, as well as identify specific economic sectors that might be disproportionately affected by such investments.
2013-02 Design and Construction Guidelines for Thermally Insulated Concrete Pavements
Researchers performed life-cycle cost analysis comparisons and developed design and construction guidelines for thermally insulated concrete pavements (TICPs). They also examined the applicability of the Mechanistic-Empirical Pavement Design Guide (MEPDG) and California models to TICPs. Results uncovered significant issues with the MEPDG’s climate model, leading to recommended corrections. Researchers developed their own models and a software companion to the MEPDG that incorporates the models. The final report includes construction guidelines for composite pavements and a life-cycle cost analysis comparing the costs of TICPs with jointed plain concrete pavements.
2013-01 Instrumentation of Navistar Truck for Data Collection
The overarching goal of this project was to instrument the new MnDOT Navistar truck used at MnROAD. A rugged data acquisition, data recording and wireless transmission system was established for collection of various sensor signals from the truck. The truck was instrumented with a suite of 20 accelerometers, with these accelerometers being located both on the five axles of the truck and on the tractor and trailer bodies. In addition, the truck was instrumented with a differential GPS system and an inertial measurement unit in the tractor cab. A cRIO-based data acquisition system, a rugged laptop and Labview software together serve as a flexible platform for data acquisition. The above instrumentation of the truck will enable data collection on truck vibrations, enable analysis of correlations between truck vibrations and variations in signals of weigh-in-motion sensors, and enable recording of truck movements and pavement loads at MnROAD.
Complete Streets Implementation Resource Guide for Minnesota Local Agencies
There is National movement and legislation regarding Complete Streets with significance for impacts on Local
Agencies. The Minnesota Local Road Research Board funded the development of this "Complete Streets
Implementation Resource Guide" that is intended as a guide to local agencies interested in developing their own
policy. This resource includes an overview on Complete Streets, a brief synthesis of local and national practices,
an understanding of the various terms and definitions, guidance on implementation and a summary of agencies in
MN with Complete Streets with complete streets policies or other guidance and projects in MN related to