MnDOT maintains nearly 400 dynamic message signs (DMS) along Minnesota highways that display real-time information to warn motorists of roadway incidents, construction or congestion ahead that could pose a hazard or cause delay. DMS use to convey weather alerts has been limited to blizzards and other very isolated winter conditions. MnDOT has been concerned about the timeliness of weather messages and the chance that such messages could be overused, possibly leading motorists to take them less seriously.Continue reading Improving Winter Road Weather Alerts on Highway Dynamic Message Signs
Transportation funding continues to be a contentious issue in Minnesota: Are we spending enough, too little, too much? One way to help answer that question is to compare spending with other states.
“A simple comparison, however, may not accurately reflect the real level of transportation funding across the states,” says Jerry Zhao, an associate professor in the Humphrey School of Public Affairs. “States face different levels of demand and costs due to different geographic, demographic, or labor market conditions.”
To better understand the factors that influence the transportation funding level, Zhao and Professor Wen Wang at Rutgers University developed a cost-adjusted approach to systematically compare highway expenses among states. They found that while Minnesota spends more than average on highways, its spending level actually ranks low in cost-adjusted measures.
“We controlled for the effects of some major cost factors, such as demographics and natural weather conditions, which are outside of the control of state and local officials,” Zhao explains. “We found that natural weather conditions have a significant impact on highway spending—a lower winter temperature is associated with higher highway expenditures.”
The effect of population size isn’t as straightforward: “There is some impact of economy of scale, but only to a certain threshold,” he says. While urban areas have greater complexity, the higher population density is associated with less spending per capita, probably due to spreading the costs across a greater population.
The analysis also found that state and local governments tend to spend less on highways when they are under fiscal stress, and states with a higher gross domestic product (GDP) appeared to spend more on highways per capita. “Essentially, highway investment decisions may be greatly influenced by the economic fluctuations and fiscal stresses faced by a state,” he says.
According to unadjusted 2010 data, Minnesota ranks 8th on highway spending per capita and 18th on its share of statewide highway spending in GDP. “But after adjusting for those factors that are largely out of control by transportation policy, we found that Minnesota’s rankings drop to 37th on highway spending per capita and 41st on the share of highway spending in GDP,” Zhao says. “This suggests that the relatively high level of highway spending in Minnesota is largely driven by the cost factors of demographics and weather conditions.”
“This study confirms what MnDOT has experienced and that transportation financing is more complicated than one would expect,” says Tracy Hatch, MnDOT deputy commissioner. “Not only is Minnesota’s transportation system significantly undercapitalized—there are considerable financial impacts from factors outside of our control.”
The analysis was conducted as part of the U’s Transportation Policy and Economic Competitiveness Program (TPEC). In previous work, TPEC researchers created the Minnesota Transportation Finance Database, which compiles data about Minnesota’s transportation finance and shows the change of transportation spending in Minnesota over time.
As the first big snow and ice storms sweep through parts of Minnesota today, we’d like to remind you of some of our great winter weather research studies. Here’s a list of some of this winter-related research from MnDOT and the Local Road Research Board:
Living snow fences
Living snow fences are trees, shrubs, native grasses, wildflowers, or rows of corn crops located along roads or around communities and farmsteads. These living barriers trap snow as it blows across fields, piling it up before it reaches a road, waterway, farmstead or community. Through multiple research efforts, MnDOT continues to advance its practices for living snow fences. Willow plants, which are which are inexpensive and fast-growing, are a new form of snow fence. MnDOT has also developed a tool that allows the agency to better offer a competitive payment to farmers.
- Evaluating the Cost and Benefits of Living Snow Fences
- Web-Based Preventative Blowing and Drifting Snow Control Calculator Decision Tool
- Assessing the Use of Shrub-Willows for Living Snow Fences in Minnesota
- Expanding the Adoption of Blowing and Drifting Snow Control Treatments on Private Lands
According to recent studies, researchers believe Minnesota could eliminate salt usage on low-volume local roads by switching to permeable pavements. Permeable pavements — pavements that allow water to seep through them — have been studied in some Minnesota cities, and a research project is currently underway to further investigate how much salt reduction can be expected.
- Permeable Pavements in Cold Climates: State of the Art and Cold Climate Case Studies
- Permeable Pavement for Road Salt Reduction
Traffic recovery during winter storms
MnDOT’s Metro District developed a way to automatically determine when to stop plowing a highway after a snow storm. The method involves measuring traffic flow to determine when road conditions have recovered. Current practice calls for maintenance workers to visually inspect traffic lanes. The automated technique could potentially be more accurate and save time and costs.
Salt and other deicing chemicals
Minnesota winters are no joke, and Minnesotans still need to get wherever they’re going despite harsh snow and ice conditions. That’s why MnDOT is constantly researching new and improved versions of salt and other deicing chemicals to keep roads safe at the least amount of damage to lakes, rivers and groundwater.
- Roadway Salt Best Management Practices
- Chloride Free Snow and Ice Control Material
- Salt Brine Blending to Optimize Deicing and Anti-Icing Performance and Cost Effectiveness Phase III
- Study of De-Icing Salt Accumulation and Transport Through A Watershed
A couple years ago, MnDOT snowplow operators in southwestern Minnesota invented an experimental plow that uses the wind to cast snow from the road without impeding traffic or the operator’s view. This winter, MnDOT intends to test multiple types of snowplow blades as part of a larger research project comparing types of deicers.
While a lot of research has been done on the plow itself, MnDOT hasn’t forgotten to invest in research to improve in-cabin snowplow technology as well. Some of the great technology recently developed to assist snowplow drivers, includes a driver assist application that a MnDOT plow driver used last winter to navigate a storm and rescue stranded motorists. The agency is also studying equipment factors that can cause fatigue in snowplow operators.
- Driver Assistive Systems for Rural Applications: A Path to Deployment
- Synthesis on GPS/AVL Equipment Used for Winter Maintenance
When the snow melts every spring, the damage salt does to roadside grass is obvious. That’s why researchers have spent years looking into developing and implementing salt-tolerant grasses on roadside settings. The result of this effort has been the introduction and use of salt-tolerant sod and seed mixtures that are made up primarily of fine fescue species. MnDOT is also studying how chlorides are transported within watersheds in order to better focus efforts to reduce deicer usage in areas where it will have the biggest environmental impact.
- Developing Salt-Tolerant Sod Mixtures for Use as Roadside Turf in Minnesota
- Best Management Practices for Establishment of Salt-Tolerant Grasses on Roadsides
- Expanding the Success of Salt-Tolerant Roadside Turfgrasses Through Innovation and Education
- Regional Optimization of Roadside Turfgrass Seed Mixtures
Cold-weather cracking prediction test
MnDOT has developed a test that can tell whether a contractor’s proposed asphalt mix will cause the road to crack in the winter. Building roads using better asphalt mixes leads to less cracking and fewer potholes. The test is expected to save the state about $2 million per year.
- DCT Low Temperature Fracture Testing Pilot Project
- Optimizing Cold In-Place Recycling (CIR) Applications Through Fracture Energy Performance Testing
- Disc Shaped Compact Tension (DCT) Specifications Development for Asphalt Pavement
Pedestrian snow removal
It’s not all about cars and trucks. Minnesotans still ride bikes and walk in the winter. That why MnDOT assembled a comprehensive review of existing practices and policies from other states, as well as a summary of valuable publications that could be referenced while developing a new policy.
Maintenance Decision Making
MnDOT research led to the development of a Maintenance Decision Support System and related components provide real-time, route-specific information to snow plow drivers, as well as recommended salt application levels. These recommendations have reduced chemical usage while still achieving performance targets for snow and ice clearance.
The Minnesota Department of Transportation is testing a crowdsourcing application that will allow motorists to update winter weather road conditions on the state’s 511 system.
The Regional Transportation Management Center is planning a soft launch of Citizen Reporting in April, initially inviting MnDOT employees to post their experiences on routes they travel. By next winter, the RTMC hopes to invite the public to do the same.
“We suspect that citizen reporters will be similar in ethic to the kinds of people who volunteer to be weather spotters,” said MnDOT Transportation Program Specialist Mary Meinert, who assists with day-to-day operations of 511.
Currently, MnDOT maintenance crews report road conditions, but Greater Minnesota lacks 24/7 coverage and its reports can become quickly outdated, especially on highways that aren’t plowed as frequently or lack traffic cameras, said 511 System Coordinator Kelly Kennedy Braunig.
Citizen reporting, especially on weekends, will help keep that information fresh.
“We try to explain on the website that we only update from 3–6 a.m., 3–6 p.m. Monday through Friday and as road conditions change, but we still get many emails requesting more frequent road condition information,” Braunig said.
Even a recent comment on MnDOT’s Facebook page pointed out the limitations in one area of the state: “Updates [only] come during government work hours.”
It’s actually a welcome sign that the public wants more from 511.
Seven years ago, when Braunig applied for her job, not many people used 511. In fact, at the time, she wasn’t even aware of the service, which provides information to travelers on weather-related road conditions, construction and congestion.
Today, 511’s online program and mobile app are accessed by more than 5,000 people per day during the winter (and about half as many during the summer). Data comes from MnDOT’s construction and maintenance offices, as well as state trooper data and incident response. This real-time information is available for all of Minnesota.
In the Twin Cities metro area, more than 700 traffic cameras allow MnDOT and State Patrol dispatchers to check the condition of 170 miles of highways and monitor traffic incidents at any time. Rochester, Duluth, Mankato and Owatonna also have cameras for incident management and traffic monitoring.
The 511 system’s greatest challenge is in Greater Minnesota, where road condition information is used daily by schools, ambulance personnel and truckers, as well as the traveling public, but information isn’t updated frequently outside of business hours. Citizen reporting will be a beneficial resource.
Other northern states face similar challenges as Minnesota, but have been able to improve the timeliness of road condition data with assistance from truckers and other motorists.
In Wyoming, more than 400 citizen reporters (primarily truckers) call in road conditions to the Transportation Management Center. In Idaho, citizen reporters directly put the information into the 511 system. Minnesota will be the fifth state to adopt citizen reporting, following Iowa, which launched its service in November 2014.
Like Iowa, Minnesota’s citizen reporting will initially focus on winter roads.
To participate, people will need to take an online training module and then register their common routes, perhaps the highways they take to work or their way to the cabin on the weekends. These contributions will be marked as a citizen report on the website.
“Minnesota truck drivers are loyal users of the 511 system and we suspect they will also make some of our best reporters,” Meinert said.
Minnesota is part of a 13-state consortium that shares a 511 service technology provider. States with citizen reporting recently shared their experiences in a Peer Exchange sponsored by North/West Passage, a transportation pooled fund that is developing ways to share 511 data across state lines.
“With citizen reporting we hope to give people a voice and a chance to participate,” Braunig said.