Road salt, most often sodium chloride (NaCl) melts ice and is a crucial tool for winter maintenance crews around the world. However, the constant application of road salt is resulting in long-term environmental and economic impacts. To slow the negative effects of sodium chloride deicers by optimizing salt use, researchers from WTI and Washington State University completed Understanding the Salt Phase Diagram, a project sponsored by Clear Roads, a Federal Highway Administration (FHWA) pooled fund. Led by Laura Fay, WTI’s Cold Climate Operations and Systems Program Manager, the team completed a literature review and laboratory investigation of the NaCl phase diagram, a graphical representation of the physical states (liquids or solid salt/ice) of salt brine depending on concentration and temperature. They distilled the information into training materials to help winter maintenance practitioners better understand the salt phase diagram and to support efficient and effective roadway deicing.
To provide visual aids for the training materials, the researchers needed to demonstrate the behavior of salt solutions in a laboratory setting. They collected video and photographic evidence of ice formation in salt brine at a range of concentrations and temperatures, verifying the familiar process of lowering ice’s freezing point with the addition of salt. They also clarified the effects of high salt concentrations on ice formation.
By synthesizing their laboratory data, the researchers created an updated NaCl phase diagram, fact sheet, and accompanying video. WTI’s Visual Communications Manager, Neil Hetherington, ensured that the phase diagram was associated with easily recognizable design elements (e.g., green = good = ice prevention). Fay noted, “Neil [Hetherington] took subject matter that was science and engineering heavy and converted it into useful, digestible information that is easily transferable. He also took time to collect quality photographs which effectively conveyed the information.”
The research has been well received. Fay has presented the training materials and findings to multiple organizations. “These materials serve as powerful education tools,” noted Fay, “and they are being used across the country.”
Walking and bicycling have become increasingly popular transportation modes as people consider the positive impacts of active living. While there are examples of large, urban areas driving the implementation of infrastructure to support these modes within their jurisdictions, communities with populations smaller than 10,000 people may have limited infrastructure and know-how. Since 84% of communities in the United States are home to 10,000 people or fewer, these geographically distributed communities can have big impacts on transportation trends.
Researchers traveled to each community to conduct on-site research on existing infrastructure and interact with community members. They collected geo-located photographs and data on active transportation infrastructure and condensed this information into infrastructure maps, conducted interviews, and provided on-site survey distribution. “For rural areas, in-person contact is key,” noted Villwock-Witte. “Local buy-in had a dramatic impact on data collection.”
The resulting case studies for each community highlight examples of active transportation infrastructure and outline characteristics that lead to a successful bike/walk culture. Also, the final report synthesizing all the case studies can provide guidance for other small communities. “These case studies,” said Villwock-Witte, “show that [bicycle and pedestrian infrastructure] does exist and describe how small communities across the U.S. have put it in place. The selected case studies are not the exception to the rule.” As existing infrastructure, such as state highways through small towns, is reimagined, communities will look to their peers for inspiration noted Villwock-Witte. “I see lots of opportunities to build on this work in the near future and for many years to come.”
The case studies and final report are available on the project page of the WTI website
The Clear Roads research program, which sponsors practitioner-focused winter maintenance research, is highlighting a recently completed severity index project on its website. For “Evaluation of SSI and WSI Variables,” the Narwhal Group and WTI collaborated to create a step-by-step guide to support implementing a severity index, paired with a flowchart tool that helps match users with existing indexes.
These tools will help winter maintenance agencies select the most appropriate storm severity index and winter severity index to compare storms across more than one winter season. “While a number of severity indexes exist, determining if you can apply or modify one for your needs or develop your own can be a daunting task. This guide and flowchart tool will support agencies in this task,” said Cold Climates Program Manager Laura Fay, who served as a co-PI. The final report is available on the WTI project webpage and there is a research brief on the Clear Roads project page.
Along a historic parkway in Virginia, the National Park Service (NPS) will soon begin improvements to enhance safety for drivers, pedestrians, and cyclists. In a recent news release, the NPS announced planned safety measures for the George Washington Memorial Parkway, which runs along the Potomac River near George Washington’s Mount Vernon Estate. The Parkway serves recreational and tourism users, as well as a growing number of commuters, which has led to increased congestion and safety challenges.
The recommended improvements stem from a major safety assessment conducted by WTI and Mead & Hunt on behalf of the Eastern Federal Lands Highway Division (EFLHD) of USDOT. The GWMP Traffic and Safety Context Sensitive Solutions Assessment, led by Principal Investigator Natalie Villwock-Witte, studied traffic conditions and crashes at nine intersections on the Parkway, then developed individual recommendations for each. Proposed alternatives were designed to enhance safety, while maintaining the character of a national park setting. The full report is available on the project webpage.
As one source of funding
for transportation projects, the federal government and all states place a tax
on fuel purchases. However, at the local and regional level, authorization and
use of fuel taxes vary widely. In
Montana, for example, state law has authorized a local option gas tax since
1979, but it has not been utilized. That
changed in June 2020 when voters in Missoula County approved a historic local
option gas tax, marking the first time any county in the state has done so.
The success of the referendum
in Missoula County may generate increased interest in this funding source by
other counties. In addition, there are
ongoing discussions at the state and national level about the viability of fuel
taxes as a sustainable funding resource in response to recent reductions in
fuel consumption and in the context of the upcoming reauthorization of federal
transportation legislation. In light of
all these factors, WTI recently completed a study to consider the revenues that
could be raised for roads, highways, streets, and bridges throughout Montana by
imposing the local option gas tax.
“An Evaluation of the Montana Local Option Motor Fuel Excise Tax” summarizes the recent history of federal and state fuel taxes, with a focus on the State of Montana and Missoula County. The subsequent analysis assesses fuel tax revenues and expenditures for roads, highways, streets, and bridges for seven Montana counties (Cascade, Fergus, Gallatin, Garfield, Hill, Madison, and Missoula). Several findings provide insights related to the contribution of fuel taxes to transportation expenditures; for example, neither state gas nor diesel taxes have kept up with inflation, and fuel tax revenues cover a relatively small share (7%-10% on average) of the roadway, highway, street, and bridge expenditures across the seven Montana counties in the study area. Moreover, the 2 cent/gallon local option tax is estimated to increase an average motorist’s costs by a relatively modest $8 – $27 per year. The full report, authored by Principal Investigator Andrea Hamre, is available on the project webpage of the WTI website.
The final report is now available for a wildlife vehicle collision study conducted for the California Department of Transportation. Road Ecology Research Ecologist Marcel Huijserand Research Associate James Begley authored the final report for “Large Mammal-Vehicle Collision Hot Spot Analysis,” which provides guidance on the implementation of mitigation measures aimed at reducing collisions with large wild mammals along all state managed highways in California, with an emphasis on mule deer. These analyses identified the road sections that had the “highest” concentration of deer-vehicle crashes and mule deer carcasses. The hot spots were prioritized based on parameters related to human safety, biological conservation, and economics. Finally, the researchers provided practical guidelines for the implementation of mitigation measures and suggest mitigation strategies for the highest-ranking hot spots in each Caltrans district.
WTI has released a new report investigating Key Deer mortality along a segment of Highway 1 within the National Key Deer Refuge in Florida. Road Ecologists Marcel Huijser and James Begley found that 75% of all reported mortalities in this area were related to collisions with vehicles. The team also investigated and mapped how the locations of collision “hotspots” have changed since the installation of wildlife fencing, underpasses, and deer guards. The final report (“Exploration of opportunities to reduce Key Deer Mortality along US Highway 1 and other roads, National Key Deer Refuge, Florida, USA”) summarizes the pros and cons of eight different strategies aimed at reducing collisions with Key Deer on Highway 1.
WTI Road Ecologists Marcel Huijser and James Begley have completed recommendations for reducing wildlife road mortalities on highways that serve two national wildlife refuges along the coast of Virginia. “Exploration of Wildlife Mitigation Measures for the Roads through and around Fisherman Island and Chincoteague National Wildlife Refuges in Virginia,” now available on the WTI website, includes specific recommendations for enhancing barriers, culverts, fencing and other methods to reduce vehicle collisions with several species of concern, including the diamondback terrapin (turtle) and the Delmarva Peninsula fox squirrel.
Natalie Villwock-Witte traveled to San Augustine, Texas in January to report on a rural transit pilot program to the Deep East Texas Council of Governments (DETCOG). DETCOG and the Area Agency on Aging launched a pilot program in 2018 to provide monthly vouchers to seniors in five counties to pay for rides to medical appointments, shopping trips, and social events. WTI, in partnership with the National Association of Development Organizations Research Foundation and the USDA, provided technical assistance for the program. Natalie reported that more than 50 area residents aged 60 and older signed up and used the program during the pilot period. “Thanks to the support of the Area Agency on Aging, the program will continue to provide rides to seniors,” said Natalie; “if DETCOG and other partners are able to secure additional funding sources, there may be opportunities to expand the program to serve other populations with transportation needs.”
DETCOG recently highlighted the project presentation on its website. Additional information about WTI’s other NADO technical assistance projects in rural communities is available on the WTI website. The pilot project final report is also available on the SURTCOM/WTI website.
A Strategic Approach to Transforming Traffic Safety Culture to Reduce Deaths and Injuries
The Transportation Research Board’s (TRB’s) National Cooperative Highway Research Program (NCHRP) has released the results of a national study on traffic safety culture, led by P.I. Nic Ward of the Center for Health and Safety Culture and Cambridge Systematics. “A Strategic Approach to Transforming Traffic Safety Culture to Reduce Deaths and Injuries” provides guidance to state transportation agencies on how to transform the traffic safety culture of road users and stakeholders, with the long-term goal of sustaining improvements in traffic safety for all road users. Background information is available on the project webpage. The report is available at http://nap.edu/25286
Citation: National Academies of Sciences, Engineering, and Medicine. 2018. A Strategic Approach to Transforming Traffic Safety Culture to Reduce Deaths and Injuries. Washington, DC: The National Academies Press. https://doi.org/10.17226/25286.
The Role of Social Capital in Traffic Safety Citizenship
Kari Finley Ph.D., Jay Otto M.S., and Nic Ward Ph.D. with the Center for Health and Safety Culture (CHSC) at Montana State University have published an article in the International Journal of Interdisciplinary Civic and Political Studies. The article titled “The Role of Social Capital in Traffic Safety Citizenship” focuses on two traffic safety citizenship behaviors: asking a passenger to wear a seat belt and asking a driver to stop texting on a cell phone while driving and explores the role of social capital to facilitate engagement in these behaviors with strangers. Results indicate that social capital may influence engagement in traffic safety citizenship behaviors. This project was conducted in cooperation with the US Department of Transportation, Federal Highway Administration and the Montana Department of Transportation (MDT), as part of a Traffic Safety Culture Pooled Fund. The article is available through Open Access and can be found at The Role of Social Capital in Traffic Safety Citizenship or at https://cgscholar.com/bookstore/works/the-role-of-social-capital-in-traffic-safety-citizenship.
Citation- Finley, K., Otto, J. & Ward, N.J. (2018). The Role of Social Capital in Traffic Safety Citizenship. The International Journal of Interdisciplinary Civic and Political Studies 13:2, 29-41. doi:10.18848/2327-0071/CGP/v13i02/29-41.