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Project Details
STATUS

Completed

START DATE

01/01/10

END DATE

10/31/11

FOCUS AREAS

Infrastructure, Safety

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Neal Hawkins

Associate Director, InTrans

Co-Principal Investigator
Omar Smadi

Director, CTRE

About the research

Minnesota Department of Transportation (MnDOT) staff has experienced that pavement markings do not perform well on seal coat and micro surface treated roadways, referred to as “challenging surfaces.” This report serves as a beginning point and organized approach in addressing pavement marking practices on challenging surface roadways.

The project objective was to document existing district practices and issues through several key tasks, which include a literature review, field review, and analysis of existing practice and performance. This effort identified the need for a field trial to provide control in the evaluation of these markings on challenging surfaces. An outline was developed for a future field trial effort, which will evaluate the marking performance of different combinations of pavement marking materials and installation practices.

These project findings will be used in conjunction with the resulting field trial evaluations to improve MnDOT guidance and standard practice that will result in better performance, efficiencies, and roadway safety.

Project Details
STATUS

Completed

START DATE

09/01/06

END DATE

09/30/08

FOCUS AREAS

Infrastructure, Safety

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Neal Hawkins

Associate Director, InTrans

Co-Principal Investigator
Omar Smadi

Director, CTRE

About the research

This project summarizes the development of a scalable, reliable, and practical process for viewing, querying, understanding, and making consistent, objective, and cost effective decisions regarding pavement marking needs, durability, and quality. The research team developed a Web-based pavement marking management system through the development environment of Microsoft Visual Studio 2005 ASP.NET in conjunction with ESRI’s ArcGIS Sever Enterprise 9.2 SP4 functionalities to manage and produce the GIS map resources. The web site hosting itself was done on a Windows based server operating Internet Information Services (IIS). The resulting web based mapping tool provides MnDOT staff the ability to map and query pavement marking retroreflectivity information and serves as a significant resource to both district and central office staff in developing short and long-term pavement marking plans.

Project Details
STATUS

In-Progress

START DATE

05/03/22

END DATE

01/31/26

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, CP Tech Center, PROSPER
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Peter Taylor

Director, CP Tech Center

Co-Principal Investigator
Halil Ceylan

Director, PROSPER

About the research

It is becoming increasingly apparent that it is necessary to explore alternative options for cement and concrete production used in public infrastructure to reduce carbon footprint. One possible process is to bubble CO2 in the fresh concrete during production to sequester CO2 and possibly to reduce cement content in the concrete without compromising system performance. Concrete with reduced cement content will exhibit reduced shrinkage reducing the risk of early age cracking. Other CO2 sequestration techniques such as dissolving it in batch water and manufacturing CO2enhanced aggregates also need to be assessed.

Confirming these benefits would be a breakthrough in simultaneously reducing the CO2 footprint while enhancing concrete performance.

Two questions are therefore raised – how much CO2 is sequestered, and what are the effects on the performance of the pavement? The goal of this research is to address these questions through testing, measurements, and the observation of concrete made with CarbonCure technology. The work will also include an assessment of the reduction of the CO2 footprint compared to control mixtures based on determining the amount of CO2 bound in the mixture as well as potential changes in maintenance needs of the pavement over the life of the pavement under traffic and environmental exposure.

Project Details
STATUS

Completed

START DATE

07/03/19

END DATE

01/31/22

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, CP Tech Center
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Peter Taylor

Director, CP Tech Center

Co-Principal Investigator
Dan King

Research Engineer, CP Tech Center

Co-Principal Investigator
Seyedhamed Sadati

About the research

The use of roundabouts in rural areas of the US is growing rapidly. For roundabouts constructed with concrete pavement, joint layout can be especially challenging. To reduce the need for sophisticated joint layouts, consideration is being given to constructing roundabouts without joints and instead using structural fiber-reinforced concrete (FRC) to bridge any cracks that might occur. In 2018, Minnesota’s first jointless FRC pavement roundabout was constructed at the intersection of Minnesota Trunk Highway 4 and County State Aid Highway 29.

The National Road Research Alliance (NRRA) sponsored a study to document the construction and performance of Minnesota’s first jointless FRC roundabout. One of the key objectives was to carry out a three-year performance monitoring regimen of the roundabout to better understand its in-situ performance when exposed to traffic loading and environmental conditions. This report documents the third-year performance of the roundabout as per the requirements of Task 3 of the work plan.

Project Details
STATUS

In-Progress

START DATE

06/04/21

END DATE

06/30/23

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, CTRE, Iowa LTAP
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
David Veneziano

Safety Circuit Rider, LTAP

Co-Principal Investigator
John Shaw

Researcher, CTRE

Co-Principal Investigator
Jonathan Wood

Faculty Affiliate, CTRE

About the research

In recent years, negative trends have emerged in pedestrian safety. Transportation agencies have sought to address these issues by implementing various pedestrian safety countermeasures at crosswalks and other conflict points.
While effective at improving safety for pedestrians, treatments can present a challenge to winter maintenance operations based on their designs and characteristics.The use of pedestrian safety countermeasures can introduce challenges to snow removal and winter maintenance operations, but misconceptions also exist. For example, one misconception is that people in the suburbs do not walk, and so keeping locations like median refuges clear of snow and ice is a lower priority for agencies.Unfortunately, research has not helped in addressing these issues. Instead, it has largely focused on the mechanics of snow and ice removal: the equipment to use, material application rates, etc., and not the impacts of designs on maintainability and pedestrian safety.
There remains a research need to investigate the best practice guidance and solutions for the design, installation, and maintenance of pedestrian safety features for year-round maintenance. With this in mind, the specific objectives of this research includes:
  • Identify current best practices for designing and implementing pedestrian safety countermeasures for year-round maintainability.
  • Document the design characteristics that make pedestrian safety countermeasures easier to maintain during the winter while using existing MnDOT and local agency equipment.
  • Review MnDOT and select local agency winter maintenance plans, polices, maintenance agreements, and procedures regarding the safety and accessibility of pedestrians and recommend options for agencies to deal with winter maintenance of pedestrian infrastructure.
Project Details
STATUS

In-Progress

START DATE

08/21/20

END DATE

09/30/22

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, AMPP
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Chris Williams

Director, AMPP

Co-Principal Investigator
Eric Cochran

About the research

As asphalt pavement oxidizes and ages, bio-materials can be used to restore flexibility to the asphalt pavement. These materials can be used in conjunction with asphalt emulsions to seal and soften weathered pavement. In the current global trade climate, there also exists a need to develop new domestic markets for US agriculture products.

This study investigates further development of using soybean-derived oils to rejuvenate pavement materials. This study is presented with 1:1 matching funds from the United Soybean Board that supports the further formulation and development of a bio-based asphalt rejuvenating fog seal.

The objective of this project is to improve current bio-rejuvenator sealant formulation and achieve stiffness reduction in oxidized, aged asphalt surfaces. The penetration of bio-rejuvenating sealers into the aged-pavement is important for reducing stiffness and restoring flexibility. This research will develop an asphalt emulsion with and without the bio-rejuvenator. The asphalt emulsion will act as the vehicle for the soybean-based rejuvenator. Surface tension reducers for the water-phase will be studied to improve the penetration of the bio-sealant into the asphalt. Particle size of the emulsion is also an important factor for penetration of the bio-sealant. The material developed in this research will be tested at MnRoads on the shoulder of the pavement. Cores will be taken to study the effect of bio-rejuvenating seal on the asphalt. The Minnesota Department of Transportation (DOT) will perform friction testing on the control and test sections to determine the extent surface friction was impacted due to the application of the bio-sealant. The four main steps in this project are (1) bio-sealant emulsion formulation, (2) bio-sealant emulsion application, (3) investigation of stiffness reduction, and (4) studying the effect of the sealant on friction.

Project Details
STATUS

Completed

START DATE

12/30/20

END DATE

08/31/21

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Shauna Hallmark

Director, InTrans

Co-Principal Investigator
Neal Hawkins

Associate Director, InTrans

About the research

Reduced traffic volumes resulting from COVID-19, along with the strain on enforcement during the pandemic, are thought to have produced higher speeds and more aggressive driving. Understanding the magnitude of speeding and other driver behaviors requires measurement and contrast. This project quantifies reductions in volume and the resulting differences in travel speeds across Minnesota along regular roads and within two work zones prior to and during the novel COVID-19 pandemic. The work includes a review of total crashes as well as fatal and serious injury crashes and includes a survey of law enforcement opinions. Findings based on 125 Automatic Traffic Recorders (ATR) and traffic Sensors quantify volume reductions, which, of course, were lower in 2020 but which varied considerably by location and month. Average speeds overall along with both the number and percentage of vehicles traveling greater than 15 mph over the posted speed limit increased in 2020. This information supports benchmarking and agency decision making.

Project Details
STATUS

In-Progress

START DATE

07/01/19

END DATE

09/30/22

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Behrouz Shafei

Structural Engineer, BEC

Co-Principal Investigator
Brent Phares

Bridge Research Engineer, BEC

About the research

Strength and durability of reinforced concrete (RC) bridges are adversely affected by the deterioration of their structural members. When investigating bridges in need of maintenance and repair, deterioration caused by corrosion of steel rebars is commonly found as one of the primary sources of structural degradation, which can eventually result in the service failure of the entire bridge under normal or extreme loading conditions. To ensure the safety of bridges, while reducing direct and indirect costs, an accurate estimate of the extent of reinforcement section loss has a central importance for a wide spectrum of engineers and decision-making authorities. Such an estimate scan be achieved through a systematic effort that benefits from the wealth of available predictive models calibrated with region-specific data and then validated through appropriate field investigations. This directly contributes to improving the predictions made for the remaining structural capacity of bridge elements and subsequently planning protective and/or corrective actions tailored to maintain the bridges in a desired condition state.
Project Details
STATUS

Completed

START DATE

07/01/16

END DATE

08/31/18

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, BEC
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
An Chen
Co-Principal Investigator
Behrouz Shafei

Structural Engineer, BEC

About the research

Many state Departments of Transportation (DOT) across the US, including MnDOT, are experiencing problems associated with loose anchor bolts used in support structures (e.g., overhead signs, high-mast light tower (HMLT), and tall traffic signals). Specifically, MnDOT inspection crews have found loose nuts at most anchor bolt locations, even at some newly installed signs. Many of these nuts became loose in less than two years, even after being tightened by the maintenance crew following current recommended procedures. This situation has placed great strain on the resources from the districts’ maintenance group and also causes concerns related to inspection frequency and public safety. This project investigated causes of the loose anchor bolts and proposes solutions based on site surveying, field monitoring, laboratory study, and numerical analysis. The research team found that the tightening process proposed in AASHTO’s specification is a sufficient alternative for MnDOT, though it requires modification in three key areas: defining snug-tight, accounting for grip length, and recommending verification procedures. The research team quantified snug-tight values, and defined the relationship between torque, tension, and nut rotation through empirical constants. Recommendations are made for a new specification for MnDOT structures.

Project Details
STATUS

In-Progress

START DATE

10/16/20

END DATE

11/30/23

FOCUS AREAS

Infrastructure

RESEARCH CENTERS InTrans, PROSPER
SPONSORS

Minnesota Department of Transportation

Researchers
Principal Investigator
Halil Ceylan

Director, PROSPER

Co-Principal Investigator
Sunghwan Kim

Associate Director, PROSPER

Co-Principal Investigator
In-Ho Cho
Co-Principal Investigator
Eugene S. Takle
Co-Principal Investigator
Daniel Rajewski

About the research

Over the last several decades, Minnesota’s winters have gotten warmer. In fact, the winters have warmed significantly faster than the summers. Such a trend is forecasted to continue into the foreseeable future. It is possible that this warming trend has increased the length of time spent around the freezing point (32°F), thus also increasing the average number of freeze-thaw events. However, it is also possible that this warming trend has resulted in no change in the number of freeze-thaw events. The proposed research has two primary objectives: (1) to attempt to quantify the number of freeze-thaw events daily, monthly, and annually from historical temperature records, freeze gauges, and other data; and (2) to attempt to collect ground/pavement temperature and study its correlation with air temperature during freeze-thaw events. To achieve these objectives, a two-phase research approach has been developed.

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