Researchers evaluated how the performance of air-entrained concrete mixtures containing water reducers, water-reducing retarders and hydration stabilizers would be affected by extending their transit time from 60 to 90 or even 120 minutes. They found no significant effect on compressive strength or freeze-thaw durability, and recommend updating MnDOT specifications to allow a longer delivery time.
The existing ultra-thin whitetopping (UTW) and thin whitetopping (TWT) design methods are reviewed so that any gaps in the design process can be identified. Four design methods are included, namely the Colorado Department of Transportation (CDOT) method, the New Jersey Department of Transportation method, the Portland Cement Association (PCA) method, and the Illinois Centre for Transportation (ICT) method. The structural response and performance models used in these methods are evaluated using field data from the whitetopping sections at MnROAD.
Researchers documented the practices of MnDOT districts and other state departments of transportation in the use of pavement markings on challenging pavement surfaces, including those with seal coat and micro-surface treatments. Results showed that agency strategies for pavement markings on these surfaces typically involve using latex paint immediately after maintenance treatments, restriping
with all-weather paint after two weeks and restriping with epoxy after one
to two years.
This report includes the design, construction, and early performance of three pervious concrete test cells construction at MnROAD in 2008. These cells were constructed to evaluate the performance of pervious concrete pavements on a low-volume road in a cold weather climate. The three cells discussed in this report are as follows: porous concrete overlay, pervious concrete on granular subgrade, pervious concrete on cohesive subgrade. This report has the following chapters, which uniquely discuss each phase of this project: research synthesis; mix design, concept design, and geotechnical exploration; construction sequence; initial testing; hydrologic evaluation; early two year performance; implementation; effect
of sound absorption on OBSI; and acoustic properties of clogged pavements.
Researchers conducted a literature review on asphalt performance tests to identify suitable candidates for inclusion in asphalt mixture specifications. Promising tests include the indirect tensile strength test, disk-shaped compact tension and semi-circular bend tests, the Texas overlay tester and the four-point bending beam fatigue test. Including a laboratory performance test in asphalt mixture specifications would improve the longevity of asphalt pavements and reduce the risk of early cracking, rutting and other deterioration.
The information in this Best Practices and Policies Guide is provided as a resource to assist local agencies in their efforts to better design, operate and maintain their systems of roads and highways. This information is provided to agencies in an effort to reduce the number of severe crashes on their highway system and it is understood that the final decision to implement any of these strategies resides with the agency. The practices and policies in this guide are consistent with guidance prepared by FHWA, AASHTO and NCHRP and is primarily intended to apply to new construction, except as noted. In addition, these practices and policies provide an overview of the current state of practice in Minnesota relating to the design,
operation and maintenance of road systems.
Researchers evaluated the pavement performance benefits of using geosynthetics in pavement base and subbase layers, including improved ride quality and reduced cracking and rutting. Results show that while geotextiles did not perform as expected, geogrids clearly benefit pavement performance.
Researchers assessed how well the use of recessed culverts in Minnesota creates hydraulic conditions, including reduced water velocities, that are more amenable to fish passage at river crossings. Of 19 sites surveyed, six were not functioning properly; a lack of sediment in the recessed culvert barrels indicated increased water velocities. Researchers determined that undersized recessed culvert barrels and accumulation of sediment in side barrels caused the lack of sediment accumulation.
The objective of this project was to develop a method for designing PBCs for highway construction projects by estimating pavement life-cycle costs and determining the amount and timing of incentives and disincentives to influence contractor behavior.
This report discusses the potential benefits and perceived impediments to implementing an automated rapid transit (ART) system in the Twin Cities and Minnesota. The report also briefly reviews the status of ART applications, also referred to as personal rapid transit (PRT), in the United States and abroad. Finally, the report evaluates the potential ability of ART to promote the policy goal of creating efficient development, livable communities, and work opportunities through a variety of relevant strategies.
To improve the accuracy of mechanistic empirical design methods, researchers developed a mathematical model to determine the built-in curl of concrete slabs using slab temperature gradients, material and geometrical properties, and falling weight deflectometer measurements at slab corners. They used this model to estimate built-in curl on pavement test sections at the MnROAD pavement research facility and found that all sections had negative built-in curl. However, the model could predict built-in curl only when total curl was more negative than -9 degrees F, which is rare in Minnesota's climate.
Researchers developed a new test rolling system and an associated construction test specification that MnDOT can use to approve compacted subgrades on construction projects. This system can be used on a wider variety of subgrade types and depths, and is safer than the previous system, allowing for a more flexible testing program overall.
This research project investigates the status of personal rapid transit (PRT) applications in airport environments, to
understand the characteristics and attributes of these systems, to explore the viability of a PRT system in the
Minneapolis-St. Paul International Airport,
and to prepare a synthesis report and presentation that document the
Motor vehicle crashes are the leading cause of teen fatalities. A Teen Driver Support System (TDSS) was developed by the ITS Institute that can allow parents to accurately monitor their teen's driving behavior in relation to known risk factors and Graduated Driver Licensing (GDL) provisions. The TDSS, based on a teen's smart phone, provides real-time, contextual in-vehicle feedback to the teen about his or her driving behavior and helps parents monitor certain known risk factors. A usability review of the prototype TDSS using 30 parent-teen dyads from Washington Country, MN, found that teens and parents held favorable opinions about most of the TDSS functions.
This report presents the Minnesota Department of Transportation's study of Astroturf texturing practices and pavement friction. The friction numbers are collected using the ASTM E 274 standard and the values from the Minnesota Road Research Project (MnROAD) were used to create a time and loading dependent model. Friction numbers from various test sections around the state of Minnesota and the model created from the MnROAD facility were then compared using visual analysis, descriptive statistics, Chi-Squared Analysis and the Mann-Whitney Z Test.
A need arose at the MnROAD research facility to provide a thin beam structural overlay on a moderately deteriorated concrete pavement test cell. This research was done to evaluate a polyvinyl alcohol fiber reinforced engineered cementitious composite (PVA-ECC) and assess the prospects to utilize the material in the bonded
The Minnesota Department of Transportation (Mn/DOT) is working on developing a replacement product for the Transportation Information System (TIS), a mainframe database management system whose purpose is the maintenance, retrieval, and reporting of roadway and railway data, including roadway accident or crash data.
This report examines the public interest in using public-private partnerships (PPPs) in state highway development by looking at maximizing efficiency gains, mitigating potential risks, and addressing public concerns in launching and deploying PPPs. The report focuses on three aspects of PPPs: understanding economic rationales of PPPs; legal and political aspects of PPP decision making;
and managerial issues associated with deploying PPP projects.
This report evaluated the performance of standard sumps as a best management practice for stormwater treatment, and found sumps were effective at collecting sediment at low-flow conditions, but the performance and required maintenance of standard sumps depend on watershed characteristics, weather conditions, and sediment loading.
This research develops a basic guide on how Mn/DOT should approach health and wellness in the workplace based on literature analysis and telephone interviews with non-Minnesota Department of Transportation safety staff and an expert in health promotion and wellness.
This research attempted to address the questions of how large wetland buffers need to be to provide sufficient protection to the wildlife and plant life from human activities that occur on adjacent land.
Innovative Diamond Grinding on MnROAD Cells 7, 8, 9, and 37
This collaborative research project looked at how the diamond grinding process could be used to enhance performance, quietness, safety, and ride comfort by testing results of research conducted at Purdue University and MnROAD Cells 7, 8, 9, and 37.
This report presents the results of a two-year study on the development and evaluation of an Advanced Light-Emitting Diode (LED) Warning System powered by solar panels and rechargeable batteries to be used on rural through/stop intersections with static warning systems that have proven ineffective.
This project developed a methodology for efficient deployment of available crew, estimation of workforce requirements, and economic evaluation of the impact of using contract employees, split shifts, and staggered shifts for snow and ice removal in Saint Louis County.
This project developed a new TONN procedure, TONN2010, for use by Mn/DOT and others. TONN2010 uses pavement layer thickness, falling weight deflectometer (FWD) deflection basins, previous day's temperature, pavement surface temperature, pavement location, and anticipated traffic to determine allowable axle loads on Minnesota low-volume roads.
In 2000, Geofoam was used as an embankment fill on Trunk Highway 100 segment 3. In 2002, it was also used at Technology Drive to correct a slope failure. Concerns about vibration issues led to a retrofit with Multi-Depth-Deflectometers and a two-year study. This paper presents the results of that study.
Maintaining the ever-growing miles of recreation trails within Local Agency jurisdiction is proving to be difficult due to the increased demands on trail use and funding limitations. The timely maintenance of paved trail surfaces and the surroundings along the corridor is critical to maintaining a good trail system. This workshop focuses primarily on the management and maintenance of the trail pavement, but also includes other elements such as vegetation, drainage, signing/striping, lighting, amenities, etc. As part of the development of the workshop, a maintenance schedule and checklist for a typical paved trail was created. This workshop steps the audience through the use of the schedule and checklist and educates them on various pavement issues and treatments.
Contact the MN LTAP center for more information on when this workshop will be offered in the future.
The use of stormwater treatment strategies, often referred to as best management practices (BMPs), has increased significantly due to new stormwater regulations. The goal of this project was to create a scoping-level tool that could assist City and County public works staff in the selection of BMPs appropriate for specific projects.
Results show that the DOT600 has the potential to be a workable and accurate replacement for MnDOT's current methods for measuring soil moisture. Comparisons of optimum moisture content using the DOT600's measurement of electrical properties—expressed as a percentage of the optimum target value for the period—are consistent with current optimum soil moisture content determined by the standard Proctor test.
Performance of test sections has not yet differed significantly enough to form definitive conclusions about the relative quality of the asphalt binders or saw-and-seal construction techniques. However, despite its higher traffic loading than other sections, the non-sawed test section using a Class 5 Modified aggregate base and PG 58-34 binder is performing somewhat better than others.
The goal of the North/West Passage Corridor pooled fund study is to develop effective methods for sharing, coordinating and integrating traveler information and operational activities between states along the I-90/I-94 corridor from Wisconsin to Washington.