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MnDOT Chooses EasyMile for Autonomous Shuttle Bus Project

Initially, it will be tested at MnROAD, MnDOT’s pavement test facility. Testing will include how the shuttle operates in snow and ice conditions, at low temperatures and on roads where salt is used. Testing is scheduled to start in November and go through February 2018. The shuttle will also be showcased during the week of the 2018 Super Bowl. (Posted 10/4/2017)

New Procedures Offer Guidance for Using Bonded Whitetopping on Asphalt Pavements

Researchers developed procedures for selecting asphalt pavements for thin whitetopping based on site examination and lab testing. Test results do not offer definitive indications of how overlaid asphalts will perform, but procedures offer recommendations on pre-overlay pavement treatment, testing protocols and design considerations for bonded concrete overlay of asphalt. (Posted 10/2/2017)

Research Confirms Low-Binder Asphalt Pavement Mixtures Prone to Cracking

Research showed that lower asphalt binder mixtures are susceptible to premature cracking. The current use of coarse-graded mix designs should be adjusted to narrow the gradation difference between larger and smaller aggregates in the mixes. While the research suggests such mixes should be used sparingly in Minnesota, it did not provide definitive data suggesting the practice should be stopped altogether. The practice may continue on a limited basis. (Posted 9/28/2017)

Field Guide Helps Local Engineers Stabilize Slopes

Researchers identified 14 sites representing destabilized roadway slopes in Minnesota. Following site investigations, lab testing and modeling, researchers recommended eight slope stabilization techniques that local engineers can undertake without the help of outside geotechnical engineers. The methods were packaged in a simple, accessible field guide for county engineers. (Posted 9/27/2017)

New Recommendations Aim to Help Roadside Turfgrass Thrive

Keeping Minnesota’s roadsides green is about more than just aesthetics—healthy turfgrass can improve water quality, reduce erosion and road noise, and provide animal habitat. However, harsh conditions such as heat, drought, and salt use can make it difficult for roadside turfgrass to thrive. (Posted 9/15/2017)

Using Smartphones to Deliver Effective In-Vehicle Work Zone Messages

Under simulated conditions, drivers were not distracted by controlled work zone-related messages delivered through smartphones. In fact, driving performance improved. Researchers also learned that the location of the smartphone did not affect the driver if the message included an auditory component. (Posted 9/13/2017)

Guidebook Reviews Enhanced Inspection Technologies for Culvert Repair

MnDOT has developed a guide that compares traditional and enhanced culvert inspection methods and tools, their limitations and costs. The guide also includes best practices for identifying when conventional inspection methods work best  and when enhanced technologies may offer good value. (Posted 9/6/2017)

Do Lower Cost Improvements to Address Congestion Lead to More Crashes?

An analysis of crash data revealed that congestion-related improvements implemented on I-35W in the Twin Cities did not introduce additional safety risks. When installed strategically, improvements like priced dynamic shoulder lanes can alleviate congestion and improve safety for motorists. (Posted 9/5/2017)

Developing a Uniform Process for Quantifying Research Benefits

Researchers worked with MnDOT technical experts to develop a method for identifying the financial and other benefits of MnDOT research projects. They developed a seven-step process for quantifying benefits and applied the process to 11 recent MnDOT research projects. Results showed that these projects were yielding significant financial benefits. (Posted 8/30/2017)

Recycled Asphalt Pavement Use is Increasing

MnDOT has long been a leader in the use of recycled asphalt pavement or RAP. Much of the nation’s current use of RAP in hot mix paving asphalt is based on the methods first used in a 1978 project that reconstructed the streets in what is now the 3M campus in Maplewood. (Posted 8/29/2017)

Clearly Marked Bicycle Lanes Enhance Safety and Traffic Flow

Researchers evaluated bicycle and motor vehicle interactions at nine locations in Duluth, Mankato, Minneapolis and St. Paul,in a study sponsored by the Minnesota Local Road Research Board to better understand how bicycle facilities affect traffic. Results show that on shared roadways without clearly marked bicycle facilities, drivers are more inclined to pass bicyclists, encroach on other traffic lanes or line up behind bicyclists than on roadways with clearly striped or buffered facilities. (Posted 8/28/2017)

New Project: Phase 3 of Drone Bridge Inspection Research Focuses on Confined Spaces

“Phase 3 will allow us to utilize a new drone specific to confined space inspections,” said Wells, MnDOT maintenance bridge engineer. “This new drone is meant to reach places the prior drones could not, which will supplement our efforts nicely. Also, Phase 3 will include more bridge inspections to get a more comprehensive feel for cost and time savings.” (Posted 8/24/2017)

MnDOT Improves on Award-Winning Use of Drones for Bridge Inspection

Phase 1 of this research project demonstrated that drones can reduce safety risks and inconvenience to bridge inspectors and the traveling public. Phase 2 shows that new drones, designed with vertical and horizontal camera and sensor capabilities for structure inspections, give bridge inspectors safe access to under-deck areas that were previously difficult or impossible to reach. The new drones cost even less than the unit tested in Phase 1. (Posted 8/24/2017)

Building More Accurate Traffic Modeling for Twin Cities Construction Projects

Researchers interviewed MnDOT and vendor stakeholders to identify needs for a mesoscopic-scale dynamic traffic assignment model for the Twin Cities. They also evaluated the capabilities of currently available simulation software packages to meet these needs. (Posted 8/21/2017)

New Project: Creating a Tool to Estimate Bridge Construction Time and Costs

The research project, titled “Bridge Construction Time and Costs,”will help the State of Minnesota’s Bridge Office develop a guidance document and a tool for bridge construction time estimation to be used by MnDOT District project managers and construction staff. The tool will provide a range of production rates based on specific design criteria, being more concise based on the level of information available and will aid in evaluating the potential benefit for accelerated bridge construction (ABC) techniques. (Posted 8/10/2017)

Using SMART-Signal Data to Predict Red Light Running at Intersections

This project developed a methodology using traffic data collected by the SMART-Signal system to identify intersections prone to red light running and, therefore, serious crashes. This methodology could help MnDOT prioritize intersections for safety improvements. (Posted 8/9/2017)

AVL Technology Enables Smarter, More Efficient Mowing Operations

A pilot project was begun to study the use of AVL technology in mowing operations. Potential benefits include improved mowing efficiency, improved reporting and ease of supervision, reduced paperwork and reduced spread of noxious weeds. (Posted 8/7/2017)

Choosing Effective Speed Reduction Strategies for Roundabouts

Using survey results and prior research, this project developed a new resource to enable Minnesota local road engineers to select appropriate speed reduction measures for roundabouts. Further research is needed to determine the relative effectiveness of different measures alone and in combination. (Posted 8/2/2017)

Self-Propelled Auto-Flagger Keeps Workers Out of Traffic

Working with a Minnesota manufacturer, researchers developed a moving automated flagger assistance device (AFAD) that signals traffic at work zones. The AFAD is operated remotely by a worker who can stand off the roadway out of traffic. (Posted 7/26/2017)

New Manual Helps Agencies Count Bike, Pedestrian Traffic

As part of an ongoing effort to institutionalize bicycle and pedestrian counting in Minnesota, MnDOT has published a new manual designed to help city, county, state, and other transportation practitioners in their counting efforts. (Posted 6/30/2017)

Gauging safety of heavy vehicles on older concrete bridges

A new study evaluates whether current guidelines regarding shear forces may be overly conservative for older concrete bridges that are in good condition. (Posted 6/2/2017)

Seven Pilot Projects to Change Transportation Practice in Minnesota

Roadside fencing that protects endangered turtles, a toolkit for identifying potentially acid-producing rock and a device that could save MnDOT $200 million a year in pavement damage are just a few of the advancements that MnDOT hopes to make in the near future, thanks to seven recently funded research implementation projects. (Posted 5/31/ 2017)

Reducing speeds to improve safety for work-zone flaggers

University of Minnesota researchers have identified and tested new work-zone warning elements to more effectively capture and sustain driver attention. The project was funded by MnDOT and the Minnesota Local Road Research Board. (Posted 5/31/2017)

New work-zone warning app featured on KARE 11

A new app that sends warning messages to drivers as they approach work zones was featured on KARE 11 News on Thursday. The app was developed by U of M researchers in a project sponsored by MnDOT. (Posted 6/26/2017)

NRRA Pavement Conference Set for May 24

Formerly known as TERRA, the National Road Research Alliance (NRRA) will continue the tradition of presenting sessions about current practices that implement new pavement research and technology with its Pavement Conference at the University of Minnesota's Continuing Education and Conference Center on May 24. (Visit the Pavement Conference website) (Posted 4/24/2017)

A Look at Local Bridge Removal Practices and Policies

To identify possible changes to how redundant and low-use bridges are identified and removed in Minnesota, the Local Road Research Board conducted a transportation research synthesis, “Local Bridge Removal Policies and Programs,” that explores how other states make bridge removal decisions. (Posted 4/19/ 2017)

I-35W 'Smart Bridge' Test Site Uses Vibration Data to Detect Bridge Defects

By analyzing vibration data from the I-35W St. Anthony Falls Bridge, MnDOT is working to develop monitoring systems that could detect structural defects early on and ultimately allow engineers to improve bridge designs. (Read the full blog post) (Posted 3/19/2017)