May 2022 Vol. 10, No. 4

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Report recommends ways to curb speeding in work zones

photo of safety barrels lined up along roadside

A new legislative report recommends speed-control vehicles, traffic cameras, and other measures to curb speeding in work zones. The report and corresponding study were completed by MnDOT and the Minnesota Department of Public Safety (DPS) as required by a 2021 state law.

A task force consisting of MnDOT and DPS staff, industry representatives, cities, counties, and stakeholder groups convened to discuss and recommend actions. Simply lowering the posted speeds will not change driver behavior, the report says, because drivers will slow down only if they perceive a need to do so.

MnDOT plans to implement nine of the study recommendations and is developing criteria for their use. Some measures will be used this year on a per-project basis, while most are more likely in 2023.

One recommendation is to use contractor speed-control vehicles on a set frequency for select construction contracts. A pilot program is planned for this construction season, according to the Minneapolis Star Tribune.

Another recommendation is to use speed safety cameras on select sites. This approach requires collaboration with DPS and a change in Minnesota statute to permit law enforcement officers to issue tickets. The report proposes a pilot program in 2023, with one deployment in the Twin Cities area and another outside the metro.

Other recommendations include more detours, additional limited or full-time closures, and greater use of end-of-queue warning systems.

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Dust palliatives for unpaved roads: Case studies, lessons learned

photo of maintenance truck generating dust on a gravel road

Photo: US Geological Survey

Dust palliatives are agents or mixtures that are applied to unpaved roads to reduce airborne dust. In a May 17 webinar, the US Geological Survey and practitioners from the field will provide lessons learned from research pilots and case studies. The webinar is one in a monthly series offered by the Federal Highway Administration Center for Local Aid Support (CLAS).

The amount of dust, and therefore the type of palliative—or road stabilizer—depends on the climate, amount of precipitation, and surface disturbance. Fugitive dust is known for its impacts to human and wildlife health, yet palliatives also come at a risk of environmental harm. Palliatives can be expensive and can erode quickly if not applied correctly for the right soil conditions.

Other upcoming CLAS webinars are Complete Streets on June 16 and Aquatic Organism Passages on July 21. All run from 1:00 to 2:30 p.m. CST.

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Entry-level driver training: Video, registry

photo of large truck on highway

Looking for information on which drivers are required to take entry-level driver training (ELDT)? The Federal Motor Carrier Safety Administration has released a video to help answer this question. Drivers are also encouraged to check their record in the Training Provider Registry.

Training providers, state driver’s licensing agencies, associations, and other partners are encouraged to share the video or embed it on their websites to help CDL applicants understand their requirements under the ELDT regulations.

Drivers who have completed entry-level driver training can check their record to see what information their training provider(s) have submitted to the Training Provider Registry.

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Traffic safety culture: Stories from rural areas

photo of overturned car at a curve in the road

Photo: Adobe Stock

While less than 20 percent of the US population lives in rural areas, almost half of all traffic fatalities occur there. A report from the Center for Health and Safety Culture shares stories from three rural communities that worked to grow their traffic safety culture.

Traffic safety culture resides in multiple layers of the social environment: individuals, families, schools, workplaces, organizations, local governments, law enforcement, and more. Growing traffic safety culture involves many diverse stakeholders working collaboratively over many years. It is a process—not a single intervention or countermeasure, the authors say.

The report provides examples from rural communities that engaged in a seven-step process for growing traffic safety culture. Tips for each step are provided.

One of the three communities was Park Rapids, Minnesota. In 2016, MnDOT funded a multi-year effort to grow traffic safety culture in the area. After using a formal process to prioritize traffic safety issues, a local coalition addressed impaired driving.

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Engaging communities for Safe Routes to School—and beyond

cover of guide: Let's Get Together: A Guide for Engaging Communities and Creating Change

A new guide from the Safe Roads Partnership offers tips and strategies to engage communities and make meaningful change. The resource is for individuals, organizations, and government agencies working on equity and engagement in Safe Routes to School and beyond.

The guide includes an engagement framework that centers community members at the heart of the process. The document walks through each step of the engagement framework in detail and offers creative ideas for engagement activities and strategies.

Each section links to additional resources and a series of guiding questions to help users improve their practice. Specific tips around engaging communities in Safe Routes to School are included.

Safe Routes to School programs improve safety, reduce traffic, and improve air quality near schools through a multidisciplinary approach.

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Tools guide purchase, deployment of tow and wing plows

photo of three plows clearing snow

Tow plows and plows with wings cost more up front but allow operators to clear more snow in a single pass than a standard front plow. A Clear Roads project assessed the efficiency benefit of equipment with variable plow widths and developed tools for decision making and procurement.

A wide range of plow attachments can extend well beyond the legal-width limit during operation and retract to legal limits when the vehicle is out of the work zone. These extendable plow attachments add significant system cost and weight and further complicate the operation of the plow truck.

This research project looked at whether the additional clearing capability justifies the costs, and, if so, what the most appropriate attachment is for the specific application. Researchers developed a decision support tool (DST) and user’s guide to analyze the cost of ownership and return on investment.

The DST, an Excel spreadsheet, calculates plowing efficiencies based on real-world plowing data and the life-cycle costs of plow configurations. The user’s guide, a PowerPoint application, lets users conduct various plowing efficiency analyses. A 10-page best practices guide helps users determine the best roadways and geometries for deployment.

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Ultra-high-performance concrete for bridge repairs increases durability

Everyday Counts

The use of ultra-high-performance concrete (UHPC) to strengthen and repair bridges has grown substantially in the past 15 years. Today, states are using it to repair bridge-deck overlays and beam or girder ends and to replace expansion joints with UHPC link slabs. UHPC is one of the innovations under Every Day Counts round 6.

UHPC’s fiber-reinforced, cementitious composite material has mechanical and durability properties that far exceed those of conventional concrete materials. State DOTs and other highway agencies have repaired or strengthened more than 20 bridges using UHPC in recent years.

A non-proprietary UHPC blend developed at the University of Michigan costs 70 percent less than commercially available UHPC mixes. Instead of buying a pre-mixed bag of UHPC, users can buy the ingredients separately and then mix them. The non-proprietary blend costs about $800 per cubic yard.

The University of Connecticut, in partnership with the Connecticut DOT, developed a more cost-effective, easy-to-implement design to repair beam ends. The Iowa DOT is using UHPC for bridge deck overlays at a number of locations.

(Condensed from FHWA Innovator, March/Apr. 2022.)

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