NCDOT Providing Material for Artificial Reefs

The North Carolina Department of Transportation is providing more than 1,000 tons of damaged concrete pipe to help the North Carolina Division of Marine Fisheries shore up two artificial reefs.

[Above photo by NCDOT]

NCDOT sent those discarded culverts – which accumulated over the past several years as the result of an aggressive pipe replacement program in part due to damage caused by recent hurricanes – to the Port of Wilmington for eventual deployment off of the Brunswick County coast.

N.C. Division of Marine Fisheries – part of the North Carolina Department of Environmental Quality – maintains several artificial reefs that create habitat for fish and ideal fishing sites.

It said artificial reefs create habitat for fish by creating three-dimensional structures that replicate the ecological functions of food and refuge fish and other marine life need to survive and create “crucial” spawning and foraging habitat for many commercially and recreationally important fish species.   

The fisheries division has been working with NCDOT to find “new and cost-effective uses” for scrapped concrete pipe. Using that piping to build artificial reefs for marine life along the state’s coastline in a money saver, the agency noted – eliminating $65,000 in tipping fees to dispose of it in a construction and demolition landfill.

Ken Clark, an NCDOT district engineer, said the idea for donating the pipe arose during a conference for coastal resiliency. That is when he discovered the state’s marine fisheries division could repurpose his stockpile of precast concrete, barreled-shaped pipe to augment existing artificial reefs. 

“We had considered many options on how to properly dispose of this unusable material when we formed this unique collaboration with the Division of Marine Fisheries last year,” he explained in a statement. “This program mutually benefits both state agencies.”

Other state departments of transportation are involved in similar artificial reef construction projects.

For example, in 2020, the New York State Department of Transportation began helping expand a series of artificial reefs off the shores of Long Island as part of a three-year-long multiagency effort – dumping a retired tugboat, 16 rail cars, and a streel turbine on Hempstead Reef.

“[We are] proud to work with our sister agencies on this important program, repurposing transportation materials to expand artificial reefs and support biodiversity, fishing, and tourism,” explained Marie Therese Dominguez, NYSDOT’s commissioner, in a statement at the time.

“It is another example of how [our state] is taking bold steps to protect our ecosystems and foster sustainable economic growth that will benefit current and future generations of New Yorkers,” she said.

Maryland Works to Reduce Road Salt’s Environmental Impact

In conjunction with several state agencies, including the Maryland Department of Transportation, the Maryland Department of the Environment (MDE) is spearheading an effort to reduce the amount of salts entering rivers, streams, and groundwater while also ensuring roads remain safe for winter travel.

[Above photo by the Maryland DOT]

MDE has been working for several years with state agencies and local jurisdictions on new salt application strategies, including use of improved weather forecasting, using the right amount of salt, targeting roads in most need of treatment, using brine to reduce overall salt usage, and increasing training for employees and contracted equipment operators.

The agency noted that Maryland DOT’s State Highway Administration (MDOT SHA) has used those and other strategies over the past five years to reduce its overall salt usage up to 50 percent.

MDOT SHA has moved to use salt brine – a liquid solution that is 22 percent salt and 78 percent water – before, during, and after winter weather events. Pre-treating roads with salt brine prevents the initial bonding of snow or ice, thus giving road crews time to mobilize. The agency now has two “tow plows” – separate plows towed behind a salt/plow truck to clear an additional travel lane – which enhance snow-clearing operations and reduce the need for road salting.

MDOT SHA has also designated salt brine-only routes for the duration of winter storms, resulting in less overall salt use when compared to routes where only rock salt is used. The agency pre-wets rock salt with salt brine to reduce the “bounce and scatter” effect of salt solids ricocheting off the highway.

MDOT SHA also works with weather forecasters to develop a treatment plan and employs more than 100 mobile infrared sensors at key locations, along with mobile sensors, to determine conditions and target its storm deployment – greatly contributing to salt reduction efforts.
“[We] congratulate and thank the Maryland Department of Transportation for leading by example when it comes to reducing the use of road salts that can threaten public health and our environment,” said Ben Grumbles, Maryland’s secretary of the environment, in a statement.

While sodium chloride or salt is effective, relatively inexpensive, readily available, and easily stored, it can destroy a soil’s structure and cause erosion, damage, and kill vegetation, while contributing to the corrosion of metal bridges and motor vehicles, MDE said. It can also seep into groundwater and runoff into surface waters, contaminating wildlife habitats and potentially affecting drinking water.

The agency noted it has increased monitoring for sodium chloride in the environment to gain information to help develop restoration plans. However, MDE noted that once salt has entered the environment there is no effective way to remove it. Thus, the best solution is a widespread, decreased use of road salt, it noted.

AASHTO Comments on Proposed Migratory Bird Permit Rule

The American Association of State Highway and Transportation Officials is “generally supportive” of a rule proposed in October by the U.S. Fish and Wildlife Service (USFWS) to develop a national migratory bird “incidental take mechanism” that also provides “flexibility” to state departments of transportation as construction seasons and bird breeding seasons vary across the country.

[Above photo of migratory swans by the U.S. Army Corps of Engineers]

The proposed rule regards the Migratory Bird Treaty Act of 1918, which protects migratory bird species between the United States and Canada. That law makes it unlawful without a waiver from the USFWS to “pursue, hunt, take, capture, kill, or sell” nearly 1,100 species of birds listed with the statute and does not discriminate between live or dead birds. It also grants full protection to any bird parts including feathers, eggs, and nests.

AASHTO stressed in a December 3 letter to the USFWS in a letter that it is desirable “to have a mechanism that allows state DOTs to propose bird management timeframes and best management practices” to limit migratory bird take.

AASHTO added that state DOTs do not support a general conservation fee as part of the transportation permitting process when migratory birds are involved. However, the organization noted that an “in-lieu fee approach” for individual transportation projects with unavoidable impacts could make sense depending on the details.

Colorado DOT Helping Reduce Impact of Firefighting Foam

The Colorado Department of Transportation’s Division of Aeronautics recently wrapped up a two-year effort to help certified commercial service airports statewide acquire equipment to minimize the environmental impact of aircraft firefighting foam containing toxic chemicals known as per- and polyfluoroalkyl substances or PFAS.

[Above photo by the Colorado DOT]

The Colorado Aeronautical Board, which oversees the Colorado DOT’s Division of Aeronautics, approved $400,000 in state aviation funding to assist with this equipment swap effort – only the second such program in the nation – in collaboration with state airports and the Colorado Department of Public Health and Environment.

This effort comes amid an increasing environmental focus on PFAS chemicals, which pose challenges to drinking water reserves.

For example, the Senate Committee on Environment and Public Works held a hearing in October to assess ongoing and proposed responses to the presence of PFAS chemicals in the environment, particularly in U.S. waters, by the Environmental Protection Agency.

Radhika Fox, the EPA’s assistant administrator for water, noted in her testimony at that hearing that a “growing body of scientific evidence” shows that exposure at certain levels to specific PFAS can adversely affect human and ecological health. Studies indicate that two common

PFAS – perfluorooctanoic acid and perfluorooctane sulfonate – can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals also caused tumors in animal studies, she said. Fox added that the most consistent findings from human epidemiology studies are increased cholesterol levels among exposed populations as well as some cases where that chemical family affected birth weights, the immune system, caused cancers, and thyroid hormone disruption.

Currently, commercial service airports certified under Federal Aviation Administration regulations are required to use PFAS-based foam and to annually test and certify aircraft rescue firefighting equipment and the foam utilized.

Under the provisions of this new statewide aviation initiative, however, the Colorado Division of Aeronautics said in a statement that it provided 100 percent funding for the acquisition of specialized testing and containment equipment designed to allow FAA-compliant firefighting foam testing to take place without the need for regular foam discharges. 

In total, 12 eligible airports participated in the division’s program, with the exception of Denver International Airport, as it already had the equipment, and Colorado Springs Airport, where the U.S. Air Force provides aircraft rescue and firefighting services.

Minnesota DOT Assisting with Bat Deterrence Research

The Minnesota Department of Transportation is helping test ultrasonic bat “deterrence devices” at two bridges to help keep the mammals away from such structures when they undergo maintenance and/or repair activity.

[Above photo by the Minnesota DOT]

The agency noted in a blog post that bats like to roost in bridge expansion joints and temporarily preventing such roosting during bridge maintenance repair activity typically requires installing physical barriers that are often difficult to establish effectively, due to the design characteristics of many structures.

More importantly, the Minnesota DOT does not necessarily want to keep bats away permanently from its bridges because bat populations throughout North America are in serious decline. For example, the agency said white-nose syndrome – a fungal disease – has killed more than 5.7 million bats in eastern North America since 2005. On top of that, wind turbines kill hundreds of thousands of bats in North America annually, according to a study by the U.S. Geological Survey.

The Minnesota DOT has worked with the Minnesota Department of Natural Resources and the U.S. Fish and Wildlife Service for the last two years testing battery-operated ultrasonic deterrence devices that reduce bat activity at bridge site when activated, but ensure a quick return of bat roosting activity when deactivated.

“This project was innovative. We worked with a technology that wasn’t really on the market yet for real-world applications in anticipation of its availability,” noted Christopher Smith, wildlife ecologist with the Minnesota DOT’s Office of Environmental Stewardship.

He added that current regulations require shorter maintenance period options during the construction season in order to protect bats – mandating that crews must avoid having bats present during their work, which impacts cleaning, painting, and other maintenance timelines.

“The presence of bats disrupts bridge work timelines and budgets, and work upsets habitation for species struggling to survive,” Smith said.

The Minnesota DOT noted that it hopes to develop a procedure for deploying this ultrasonic bat deterrence technology when needed and determine associated expenses from this two-year research effort.

Further study could consider the technology in different configurations and environments, test the devices at many bridges around the country, and conduct a cost-benefit analysis, the agency added – while also comparing the “relative impact” of acoustic deterrents on specific bat species.

Report Urges More Funding for Colorado DOT Wildlife Protection Projects

A state government report is calling for increased funding for transportation projects that protect big game habitats and corridors and prevent thousands of vehicle-wildlife crashes each year on Colorado’s roads.

[Above photo by the Colorado DOT]

The Colorado Department of Transportation and the Colorado Department of Natural Resources authored the Big Game Policy Report, subsequently released by Governor Jared Polis (D) on September 29.

A statement from the governor’s office said the report seeks to “prioritize state policy, coordination and investment to support our wildlife and ecosystems.”

The report notes that the effects of climate change, increased industrial, residential construction, plus ongoing infrastructure development increase the number of situations putting wildlife in conflict with people. The most glaring examples of such conflicts are the estimated 4,000 vehicle crashes with wildlife that cost an estimated $80 million each year in Colorado.

The Big Game Policy Report served as a follow-up to an executive order Gov. Polis issued in 2019 directing Colorado DOT to incorporate wildlife protection measures into “all levels of its planning process, to the greatest extent possible.”

The Colorado DOT already planned to make road improvements to U.S. 160 between Pagosa Springs and Durango when it decided to incorporate wildlife protection elements. The busy stretch of highway has been the scene of more than 350 big game-vehicle collisions in the last 10 years as drivers make their way to the Chimney Rock National Monuments.

The project, expected to wrap up this winter, now includes a wildlife overpass and underpass, high-deer fencing, and “jump out” ramps within the two-mile project area. The fencing helps “funnel” the moving herds toward the overpass or underpass, where they can safely cross the busy highway. The earthen ramps are inside the fencing and allow the animals to safely escape traffic.

By including wildlife elements into planned projects, “it gives us a bigger bang for our buck,” said Lisa Ann Schwantes, a Colorado DOT regional communications manager.

“We look at the projects already identified that need to be done, and we overlap them with wildlife projects and marry them together,” she said.

Though incorporating wildlife protection elements into existing planned projects can be cost-effective, the costs still add up. The U.S. 160 project has a total price tag of $12 million, $5.4 million of which include just the construction costs for the wildlife protection features.

The report points out that, while Colorado DOT continues to look for ways to protect big game and drivers from each other, the agency has no dedicated funding source for such wildlife projects – one reason why the new report calls on the state legislature to find new money to support such projects.

“While progress has been made, the General Assembly should prioritize new funding for transportation projects identified by CPW (Colorado Parks and Wildlife) and Colorado DOT that provide a clear benefit to wildlife populations and human health,” the report states.

Colorado DOT Helps Complete I-25 Wildlife Underpasses

The Colorado Department of Transportation and the Colorado Parks and Wildlife (CPW) agencies recently completed wildlife underpasses along a rural stretch of Interstate 25 between Colorado’s two largest cities, Denver and Colorado Springs.

[Above photo by the Colorado DOT]

This wildlife mitigation system is part of a $419 million transportation improvement project – known as the I-25 South Gap project – that aims to improve safety and travel on 18 miles of I-25 south of the Denver metropolitan region; a route that more than 87,000 motorists use on a daily basis.

The I-25 South Gap project’s wildlife mitigation system includes four new and one refurbished wildlife underpasses, 28 miles of deer fencing, and deer guards and jump-outs, Colorado DOT said.

Work on the underpasses is substantially complete with 8 percent of deer fencing installed – just in time to shepherd migrating wildlife safely under the interstate this fall. The I-25 South Gap project as a whole, however, should be finished by 2022, the agency noted.

The Colorado DOT and CPW are also now in the process of installing 59 cameras throughout the project’s wildlife mitigation system to help measure success.

Shoshana Lew, executive director of the Colorado DOT, said that these wildlife underpasses – used by bears, elk, and small game animals – are also some of the largest in North America.

“One of [our] core values is safety, and we are thrilled to deliver on this value to all who use I-25 in the area,” she explained in a statement.

“In Colorado, nearly 4,000 animal-vehicle crashes are reported annually, resulting in injuries and fatalities to people and costing an estimated $80 million,” Lew added. “In the I-25 South Gap, it is estimated that one animal-vehicle crash occurs per day. Our wildlife mitigation system aims to reduce these crashes by 90 percent.”

Photo by Colorado DOT

“Colorado DOT met with various agencies, including CPW, early in the planning process to come up with a collaborative solution,” noted Brandon Marette, land use coordinator for CPW’s Northeast Region. “Fast forward from our first collaboration meeting nearly five years ago to today, where wildlife is now using the underpasses that we planned together. There is more collaboration to come between our agencies as we continue to plan and implement strategies to keep both people and wildlife species safe, thus protecting what is unique to Colorado.”

State departments of transportation in various parts of the country have been working on ways to improve wildlife mitigation tactics over the past several years.

In 2019, the Pew Trusts issued a report that highlighted the work states are doing to boost safe passage for wildlife around roadways, while at the same time improving motorist safety.

“Big-game animals in the American West today are increasingly squeezed by growing suburban areas, energy development, climate change, and an expanding road network,” noted Matt Skroch, a manager with the Pew Charitable Trusts’ U.S. public lands and rivers conservation team and author of the report, at the time.

“[Those] factors are threatening the landscape connections that wildlife needs to move to and from their seasonal feeding and breeding grounds,” he added. “To conserve wildlife corridors while reducing wildlife-vehicle collisions in the West, state and local governments need to take the lead on these issues and guide their agencies to effectively link science with policy. Fortunately, this is beginning to happen. From Montana to New Mexico, states are identifying hot spots where collisions occur and linking those areas with the larger habitat conservation needs on either side of the road.”

For example, in April, the construction of the new Rock Creek Bridge to replace a culvert on US-20 recently won an engineering excellence award from the American Civil Engineers Council of Idaho – an award shared by the Idaho Transportation Department (ITD) and Jacobs Engineering. That new bridge now allows wildlife to pass under the highway, reducing the risk of possible collisions involving wildlife and vehicles on the roadway.

The ITD added in a statement that this particular section of US-20 witnessed 64 vehicle-wildlife collisions over the last five years, which totals a “societal cost” of approximately $2 million when adding together the cost of vehicle repair or replacement, medical bills, and increased insurance rates – not to mention the cost to wildlife.

WSDOT Culvert Project Keeps Traffic, Fish Moving During Construction

If culverts under a busy state road are clogging a creek and preventing fish from migrating, how do you simultaneously replace the culverts, maintain traffic on the road, and protect the fish during construction?

[Above photo by WSDOT]

This riddle proved a real-life challenge for the Washington State Department of Transportation, which came up with an innovative answer – leave the culverts in place, build a new bridge somewhere else, and move the creek under it.

More than 50 years ago, the agency installed two 8-foot box culverts on State Route 3 over Chico Creek, home to the biggest chum salmon population in Kitsap County. In 2013, a federal court ruled that the abutting culverts were among 1,002 fish barriers in western Washington and ordered their removal by 2030.

The reason is that culverts create a “choke point” for fish – accumulating debris, narrowing the creek, and preventing thousands of salmon from making the annual spawning trek through the creek to the freshwater bay to lay their eggs. Above the creek, about 50,000 vehicles a day drive on SR 3, so a construction plan had to consider travel patterns of fish and motorists.

The WSDOT solution is a $58.3 million design-build project that features new bridges on SR 3 and nearby Chico Way, two realigned ramps, and two engineered creeks beneath the new bridges. The project will keep traffic and fish moving during and after construction.

An engineered waterway like this one for Coffee Creek is being built for Chico Creek. Photo by WSDOT.

Crews building a new SR 3 bridge just east of the culverts are simultaneously maintaining traffic volumes by shifting lanes toward the outside shoulders while the center portion of the bridge is constructed. Then traffic will shift again, to the inside shoulders, while the rest of the bridge is finished. Once SR 3 bridge construction is completed, crews will realign traffic lanes with the new bridge.

Meanwhile, crews are building an “engineered creek” that will realign Chico Creek to bypass the old culverts to pass under the new bridge. Construction work to redirect Chico Creek to the new channel will take place during “fish windows,” when construction work will do minimal damage to fish.

The engineered creek includes native vegetation, strategic bends, and elevation changes designed to support “every life cycle of fish,” said Doug Adamson, a WSDOT spokesman. It will feature places for fish to lay eggs and hide from predators, allowing the salmon to “naturally move” from fresh water to saltwater habitats and back again, Adamson said.

The project also includes a new bridge, two realigned ramps, and a second engineered creek at nearby Chico Way. This work will eliminate fish barriers to an unnamed tributary that feeds into Chico Creek by realigning the tributary and giving it a much wider channel under the new Chico Way Bridge.

The entire project, which will improve access to 21 miles of potential habitat, is regarded as one of the most significant fish barrier removal projects in western Washington due to the number of fish involved and because of the cultural impact to the Suquamish Tribe, whose ancestors have inhabited the area for thousands of years.

The project comes 30 years after WSDOT first created a dedicated program to remove barriers to fish under state highways. Since 1991, the agency has fixed 344 barriers, opening a total of 1,161 miles of fish habitat. “We are opening up dozens and dozens of miles for habitat for fish who couldn’t reach these areas since the highways were first built,” Adamson said. “We are making up for mistakes made in the past. We are working to rectify those mistakes to improve the habitat for native fish.”

Georgia DOT Participating in Statewide Pollinator Project

The Georgia Department of Transportation and the Georgia Association of Conservation Districts or GACD are planning to install 15 pollinator habitat sites in designated locations as part of a joint effort to educate state residents about the important role “pollinators” such as bees, butterflies, and other insects play in Georgia’s agricultural sector.

[Above photo by the Georgia DOT]

“This partnership provides Georgia DOT with the unique opportunity to create a place for families and travelers to get up close and personal with the wildflowers and grasses [to] learn about how they impact the world around us,” explained Felicity Davis, a landscape architect manager with the Georgia DOT, in a statement.

“We carefully considered the locations for these gardens and with pedestrian safety in mind, we determined the best option would be at rest areas and Welcome Centers across the state,” she said.

GACD received grant funds from the U.S. Department of Agriculture’s National Resources Conservation Service to install pollinator habitat sites and promote the further establishment of such gardens by landowners throughout the state. Through a memorandum of agreement, Georgia DOT and GACD entered into a partnership to fulfill the requirements of that grant.

GACD will provide funding to Georgia DOT’s Roadside Enhancement and Beautification Council, with the department installing and maintaining the gardens while GACD provides and maintains “educational signage” about them. The grant requires both agencies to complete the planting work for those pollinator sites by August 2022.
“Pollinator plants and insects not only play a critical role in supporting our state’s environment and agriculture, but with the specific mix of wildflowers and native grass being planted, the gardens will also provide year-round interest and habitat for insects and small animals,” said Mark Masters, GACD president. “We are excited this partnership has come to fruition and look forward to getting the gardens installed.”

State departments of transportation are involved in a variety of pollinator support efforts.

The Tennessee Department of Transportation, along with the Tennessee Department of Environment & Conservation and Tennessee Department of Agriculture, jointly promoted “pollinator health and awareness” in state parks during National Pollinator Week June 21-25.

The three agencies formed a partnership in 2019 to support 64 acres of “pollinator meadows” at eight state parks. Each blooming meadow contains a mix of nectar-bearing plants and milkweed, which sustain pollinators such as bees, moths, butterflies, birds, and small mammals such as bats.

In March 2020, the American Association of State Highway and Transportation Officials sent a two-page letter to the U.S. Department of the Interior supporting “expedited approval” of the voluntary national Candidate Conservation Agreement with Assurances or CCAA to further encourage the creation of pollinator habitats in highway rights-of-way.

The CCAA – eventually finalized in April 2020 – provides a “huge boost” for the conservation of Monarch butterflies and other pollinators on a landscape scale, the U.S. Fish & Wildlife Service noted at the time.

“The regulatory protections provided by this CCAA allow transportation agencies to continue vegetation management practices with less concern that these actions will lead to an increase in the costs of regulatory compliance if the monarch is listed under the Endangered Species Act,” AASHTO said in its letter.

In December 2020, the Transportation Research Board highlighted a bevy of resources available to state departments of transportation to support monarch butterfly habitat and migration support efforts.

To that end, a new report from the TRB’s National Cooperative Highway Research Program – Evaluating the Suitability of Roadway Corridors for Use by Monarch Butterflies – provides guidance for roadside managers to determine the potential of their roadway corridors as habitat for monarch butterflies.

The report also includes several tools and decision-support mechanisms to optimize habitat potential in a manner that is compatible with the continued operation and maintenance of the roadside.

MnDOT Trying to Cut Back on Its Salt

When it snows in Minnesota, drivers want the roads and bridges cleared – now.

However, simply dumping mass amounts of salt on the roads is an outdated practice for the Minnesota Department of Transportation. Today, the agency is taking a new strategic – and more environmentally friendly – approach to how it removes snow and ice.

[Above photo by the Minnesota DOT]

“We want to minimize what we use,” explained Sue Lodahl, Minnesota DOT’s acting state maintenance engineer. “It’s about using the right chemical at the right time in the right location.”

During the 2020-2021 winter season, the agency spent $116 million and used more than 800 plow trucks and 354 million pounds of salt to combat 53 inches of snowfall, according to the department’s Annual Winter Maintenance Report. The salt usage was down about 15 percent from the previous year.

[To learn more about snow and ice fighting tactics, check out the winter operations podcast put together by the American Association of State Highway and Transportation Officials Snow and Ice Pooled Fund Cooperative Program, known as “SICOP.”]

The Minnesota DOT has also published “Winter Maintenance Best Practices,” a guide for using salt, with an emphasis on sustainable practices. “MnDOT seeks to reduce the use of salt on roadways while maintaining a high level of performance with regard to level of service recovery in winter operations,” the guide states.

The department’s Salt Solutions Program helps operations personnel make good decisions about selecting the best and safest materials for clearing the roads. As a result, the Minnesota DOT’s maintenance crews now have an arsenal of tools to fight snow and ice – including salt, potassium acetate, calcium chloride, sodium acetate and even beet juice.

[Editor’s note: The Minnesota DOT also began testing the technology on 10 of its snowplows in January that allows operators to activate digital highway signs to warn motorists when slow-moving vehicles are ahead on the road. That technology activates digital message signs to display certain messages as they pass, such as “Snowplow ahead, use caution” or “Maintenance vehicle ahead, use caution” during non-snow events. The message stays activated for several minutes after the snowplow passes the sign.]

[Above photo by the Minnesota DOT]

Even with all the chemical options available, plain road salt – sodium chloride – is still the “go-to” material, yet it has its limitations. Salt is not effective if the temperature drops below 15 degrees Fahrenheit.

Moreover, if salt washes off the road, it can harm water, vegetation, and wildlife.

“We’re always going to use granular salt, but we’re trying to keep it on the road,” Lodahl said. “You can’t just put down salt. Otherwise, it will go into the environment.”

The Minnesota DOT also “pre-wets” the salt with truck sprayers just as it hits the road. The water helps the salt stay on the roadway, where it reacts to the heat from vehicle tires. “But if the temperature is less than 15 degrees, that’s when we move into calcium chloride,” Lodahl pointed out.

The department’s top priority is to achieve what it calls “bare lanes,” a condition in which 95 percent of the lane between the wheel tracks is free of snow and ice and travel speeds are not impacted. Last winter, the Minnesota DOT saw bare lanes 87 percent of the time. The Salt Solutions Program’s goal is to strike a balance between achieving bare lanes and protecting the environment.

In 2020, the agency also studied using potassium acetate almost exclusively on roads in Duluth, where the average daily winter temperature is 23 degrees. The study showed promise, but there are still some environmental unknowns about the long-time use of potassium acetate, Lodahl said.

“Salt is still our biggest tool, our best tool,” she explained. “Everything is going to have some environmental factor. If salt scatters, it’s not doing us any good, and it harms the environment.”

Lodahl added that salt sustainability “is very important to MnDOT. We cherish the environment and try to keep the roads safe.”