Category Archives: Research

General research posts.

Policy and Planning, Research

Transportation spending: How does Minnesota compare with other states?

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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.

Materials and Construction, Research

Thicker may not equal stronger when building concrete roadways

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Transportation agencies have long placed high importance on the thickness of their concrete roadways, making it a major focus of control and inspection during construction. While it is commonly believed thicker concrete pavements last longer, there is little data to support this claim.

“One big reason for the lack of data on the relationship between concrete pavement thickness and performance is the destructive nature of these measurements,” says Lev Khazanovich, a former professor in the University of Minnesota’s Department of Civil, Environmental, and Geo- Engineering. “Concrete thickness is typically assessed by coring—a destructive, expensive, and time-consuming test that only offers widely spaced measurements of thickness.”

In a MnDOT-funded study, U of M researchers set out to fill this knowledge void by leveraging recent advances in the nondestructive testing of pavements that allow for large-scale, rapid collection of reliable measurements for pavement thickness and strength. They conducted four evaluations on three roadways in Minnesota using ultrasonic technology to collect more than 8,000 measurements in a dense survey pattern along with a continuous survey of observable distress.

“We found that both pavement thickness and stress measurements are highly variable, with a half-inch of variation in thickness about every 10 feet,” Khazanovich says. “Interestingly, three of the four surveys averaged less than design thickness, which is contrary to typical accounts of contractors building slightly thicker slabs in order to avoid compensation deductions.”

Data analysis showed that exceeding design thickness did not seem to increase or decrease pavement performance. However, a measurement of pavement strength and quality known as “shear wave velocity” did produce valuable findings. “A drop in the shear wave velocity strength measurement corresponded to an increase in observable pavement distresses such as cracking and crumbling,” Khazanovich explains. “This was especially apparent when we were able to easily identify locations of construction changes, where significant changes in shear wave velocity matched up with observable distress.”

The results of this study illustrate the importance of material quality control and uniformity during construction, since alterations in pavement strength and quality may significantly influence pavement performance. In addition, researchers say that despite inconclusive thickness results, it is still important that pavement has significant thickness to carry its intended traffic load over its service life. Finally, the study demonstrates that new methods of ultrasonic shear wave velocity testing are useful for identifying changes in construction and design that could lead to higher rates of pavement distress.

Public Transit, Research

For millennials, car ownership and family life may not be obstacles to transit use

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As the millennial generation comes of age, indications of a significant generational change in travel behavior have raised hopes of robust growth in transit use. As a whole, this generation owns fewer cars, drives fewer miles, and uses transit more than previous generations. However, one key question remains: will millennials continue their high rates of transit use as the economy improves and they increasingly settle down and start families?

“In older generations we have seen significant declines in transit use that coincide with the transition to family life and child rearing,” says Andrew Guthrie, a research fellow and Ph.D. candidate at the Humphrey School of Public Affairs. To gain insight into the question of whether the millennial generation will be different, Guthrie looked for changes in the extent that two factors—young children in a household and access to a vehicle—affect transit use.

The study, conducted with Humphrey School associate professor Yingling Fan, looked for evidence of these bellwether changes in the Minneapolis–Saint Paul region between 2000 and 2010. This period saw the opening of the region’s first modern light-rail line as well as numerous bus system improvements, including a network of high-frequency local routes. In addition, the region has a strong, knowledge-based economy and has seen an in-migration of millennials.

The researchers used data from the detailed Travel Behavior Inventory conducted by the Twin Cities Metropolitan Council in 2000 and 2010 to compare travel behavior at both the trip and person levels.

Their analysis revealed that both young children in a household and access to an automobile have become “weakening obstacles” to transit use. “Specifically, research models show that participants with access to an automobile were more likely to use transit in 2010 than in 2000, and that participants with young children in their households were less likely than others to use transit in 2000 but not in 2010,” Guthrie says.

“Our models provide strong evidence that the basic relationship between transit use and the presence of young children in a household has changed, as has the relationship between transit use and access to an automobile,” Fan adds. “In fact, regardless of the specific modeling approach, these two traditional obstacles to transit use either weakened or disappeared entirely between 2000 and 2010 in the Twin Cities region.”

According to the researchers, the findings suggest that transit may now be better able to hold on to market share as its millennial users mature and start families, especially in urban areas where walk-and-ride trips are most common. In order to attract and accommodate these transit users, researchers believe ensuring an adequate supply of family housing and family-oriented community features such as high-quality schools and playgrounds in transit-served areas will be critical.

The research this paper was based on was part of a larger project funded by the Metropolitan Council and MnDOT. The paper was recently published in the Transportation Research Record.

Research, Traffic and Safety

Project seeks to ease traffic congestion in a roundabout way

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Freeways and highways aren’t the only urban roads with traffic congestion, even though traffic management strategies have been largely directed toward improving traffic flows there. So, U of M researchers have taken to city streets to reduce congestion in an innovative—albeit roundabout—way.

“There’s been a lot of research focused on controlling congestion on major highways and freeways, but there’s relatively less when it comes to looking at controlling traffic on urban arterials,” says Ted Morris, a research engineer with the Department of Computer Science. “It’s a very different picture when you get into urban arterials and the traffic behaviors going on there, because of the dynamics of route choice, pedestrian interactions, and other factors.”Image of overhead view of roundabout

Morris is part of a research team that aims to create a framework for testing and evaluating new urban traffic sensing and control strategies for arterial networks. The goal is to balance safety and efficiency for all users—especially in places where new types of urban transportation facilities are planned in the next few years.

The team is using the 66th Street corridor in Richfield as a test bed for its research. The city, along with Hennepin County, is in the process of converting a series of signalized intersections along the route to roundabouts over the next few years. The roundabout designs also incorporate new facilities for pedestrians, bikes, and bus transit as part of a multimodal approach.

Initially, the researchers sought to create a larger network of interconnected sensors and a live test bed, Morris says. But funding limitations kept the project area to approximately 10 miles of arterial roads, a portion of which will be supported by a network of interconnected traffic sensors. The research team is instrumenting major intersections along 66th Street with a reliable, low-cost, high-resolution camera mounted on a center pole and supporting electronics as the intersections are being reconstructed.

“You can zoom in pretty closely to capture all the different movements and events that we need to use for measurement and detection,” Morris adds. “The key to this, to really make it reliable, is you need to very carefully quantify gap acceptance and how that varies in time and time of day. You also need to know how pedestrian activities interact with the traffic flow.”

The use of roundabouts has grown in the region because they cost less to build and maintain than signalized intersections, they meet the latest design standards, and they improve safety by reducing traffic conflicts. But predicting the capacity of roundabouts can be especially challenging when factoring in pedestrian traffic, uneven traffic origin-destination flow, heavy vehicle volumes, and approach vehicle gap-selection timing.

In addition to creating a sensor network to obtain real-time vehicle and pedestrian data to help control traffic and keep it flowing smoothly, the researchers also are developing a traffic simulation model that includes almost all of Richfield—more than 140 signalized intersections covering 21 square miles, including the arterials. The simulation model will be used to develop and test traffic control strategies under different scenarios. Minnesota Traffic Observatory director John Hourdos is leading that effort.

This research and the field deployment system are funded through a collaborative grant from the National Science Foundation Cyber Physical Systems program. SRF Consulting is the industrial partner to help design the sensor network and evaluate the system.

Maintenance Operations, Research

Winter Decision-Making Crosses State Lines

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Winter weather events have a regional and often national impact. “Storms never stop at the state line,” said Tom Peters, research and training engineer, MnDOT Maintenance Operations. “That’s why it’s so important for us to know about winter maintenance efforts around the country, and particularly at neighboring states with similar climates.”

MnDOT leads the Clear Roads Transportation Pooled Fund Project (clearroads.org), a national winter maintenance research consortium. In 2015, Clear Roads launched a national survey to collect and report the annual winter maintenance operations of state DOTs. The effort included nearly 50 data points related to equipment, materials and costs.

The results, which are available at clearroads.org/winter-maintenance-survey as a Microsoft Excel-based spreadsheet, are available at no cost for users to examine, analyze and parse as needed. Beyond the raw data, the spreadsheet includes calculated statistics and an interactive map for plotting key metrics.

The results quantified much of what was known only anecdotally and provided useful, actionable data. “Data trends by geographic region and over time let us make more informed operations decisions,” Peters said. “We can also draw on this information to communicate with management, elected officials and the public about how MnDOT’s winter operations fit in a national context.”

As the lead state, MnDOT commits significant administrative time and attention across the agency to Clear Roads. “It’s rewarding and satisfying to see such a useful product as one of the payoffs for all this effort,” Peters said.

Additional data collection for the 2015-2016 winter season is already complete. Look for an update to the online database later this year.

Research in Progress

Clear Roads has nearly a dozen research projects in progress, including:

See all of Clear Roads’ current research projects at clearroads.org/research-in-progress.

What’s Next?

At its September meeting in Omaha, Nebraska, the Clear Roads Technical Advisory Committee funded five new projects:

  • Utilization of GPS/AVL Technology: Case Studies
  • Standards and Guidance for Using Sensor Technology to Assess Winter Road Conditions
  • Emergency Operations Methodology for Extreme Winter Storm Events
  • Weather Event Reconstruction and Analysis Tool
  • Training Video for the Implementation of Liquid-Only Plow Routes

What is Clear Roads? 

Clear Roads is a 33-member pooled fund program dedicated to winter road maintenance research. Led by MnDOT, Clear Roads projects evaluate winter maintenance materials, equipment and methods; develop specifications and recommendations; study and promote innovative techniques and technologies; and develop field guides and training curricula. Learn more at clearroads.org.

Research

Newly funded studies tackle big transportation questions

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Can Twin Cities roadsides be used to grow habitat for endangered bumble bees? Are unseen factors affecting safety at rural intersections? How should Minnesota transportation agencies be preparing for connected vehicle technology?

Minnesota’s next round of transportation research projects will attempt to solve these and other questions facing the state’s transportation community. The Transportation Research and Investment Group, which governs MnDOT’s research program, and the Minnesota Local Road Research Board, which represents cities and counties, recently met and selected 21 transportation research projects for funding in fiscal year 2018.

A couple of MnDOT’s most interesting projects will evaluate the reuse of wastewater at safety rest areas and truck stations and develop a system to optimize the location of 80 truck stations due for replacement in the next 20 years. MnDOT will also partner with the Local Road Research Board to evaluate the use of personal warning sensors for road construction workers.

In addition to the problem of stripping underneath sealcoats on some city streets, other top research projects for local governments involve pedestrian safety enforcement and investigating whether rural, low-volume roads should be treated differently than urban roads for stormwater runoff. Current regulations govern runoff the same, regardless of daily vehicle count or surrounding land use.

“The selected research studies, which typically take one to three years to complete, will address some of the most major policy, environmental and maintenance dilemmas facing transportation practitioners,” said Linda Taylor, director of MnDOT Research Services & Library.

Below is a list of the selected projects, with links to associated need statements. Final project scopes will become available once contracts are approved. For further information, go here.

Bridges & Structures

Materials & Construction

Environmental

Planning

Maintenance Operations

Traffic & Safety 

Environment, Maintenance Operations, Research

10 Ways Transportation Research Keeps Minnesotans Moving in the Winter

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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.

Related studies:

Permeable pavement

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.

Related studies:

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.

Related study:

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.

Related studies:

Snowplow blades

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.

Related study:

Snowplow technology

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.

Related studies:

Salt-resistant grasses

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.

Related studies:

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.

Related studies:

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.

Related study:

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.

Related studies:

Environment, Maintenance Operations, Research

Knowing While Mowing: GPS Keeps Maintenance Workers Out Of the Weeds

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As temperatures fall and days get shorter, MnDOT Metro District maintenance workers are wrapping up a season of mowing grass along roadsides and in medians that they hope will prove a little more efficient than in the past.

Thanks to a research project that installed GPS devices in tractor cabs, operators have a better sense of exactly which areas they need to mow and which areas should be left alone. Five Metro District tractors were tested in 2015. This year, more than 40 tractors were fitted with the automated vehicle location (AVL) technology, which includes a GPS antenna, an on-board central processing unit (CPU) and an in-cab screen with a user interface.

Trisha Stefanski, Metro District asset management engineer, expects one of the biggest benefits of the project to be a reduction in herbicide use. Maintenance crews use herbicide to control the spread of noxious weeds that sometimes get spread during mowing operations. Mapping exactly where noxious weeds are, and providing that information to operators on a real-time, in-cab screen and user interface helps them mow around those areas.

“We’re really hoping it will reduce the amount of herbicide that we’re putting on our roadways by 50 percent,” Stefanski said. “We’re not certain that will be the number, but that’s what we’re hoping for. We think just not mowing those areas will not spread as many noxious weeds and so we don’t have to apply as much herbicide.”

Metro District operators, such as Jesse Lopez, give the AVL technology rave reviews.

“Basically you can see what you shouldn’t mow and what you should mow. So, it makes it easy for me. It’s just like playing a game,” Lopez said. “This actually helps me to optimize what my job is. I know exactly where I’m at and where I’m going. I think everyone should use it – absolutely everybody who is in a mowing situation or a plowing situation.”

In addition, the AVL technology helps maintenance supervisors keep tabs on exactly where their operators are in real time. It also helps supervisors complete reports by automatically providing the geographic areas where mowing has been completed.

Stefanski says the project has gone really well, and she hopes collecting more data over another mowing season will show real savings on herbicide use. In the meantime, she is thinking of other ways AVL technology could be applied to maintenance operations.

“What I really like about the project is that we are taking something used in a lot snow plows and a lot of other technologies – cars, other things, maybe UPS uses them – and we’re putting it into maintenance operations,” Stefanski said. “Having it for mowing, we can also use it for smooth pavements. We can also use it for other things in mowing operations.”

Bridges and Structures, Research

Drone Project Earns State Government Innovation Award

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The MnDOT Office of Aeronautics and Aviation was recognized last month for the drone research project that also involved the Office of Bridge and Structures and MnDOT Research Services.

The Humphrey School of Public Affairs, in partnership with the Bush Foundation, presented a State Government Innovation Award to recognize great work and to encourage an environment that allows agencies to deliver better government services to Minnesotans through creativity, collaboration and efficiency.

The project, titled Unmanned Aircraft Systems (UAV) Bridge Inspection Demonstration Project, found that using drones for bridge inspections improves safety, lessens traffic disruption and reduces work time. For one type of bridge, inspection time shrank from eight days to five.

In the video, Jennifer Zink, MnDOT state bridge inspection engineer, explains the project, along with Tara Kalar, MnDOT associate legal counsel; Cassandra Isackson, director of MnDOT Aeronautics; and Bruce Holdhusen, MnDOT Research program engineer.

The initial drone project drew significant media coverage and a lot of attention from other state departments of transportation from all over the country.

A second phase of the project was approved year and is currently underway. A third phase is already in the planning stages.

More information

Research, Traffic and Safety

Work Zone Safety- How to Make Construction Sites Safer

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If you have spent any time driving on Minnesota roads and highways lately, you know that road construction work zones are all over the place. They can contribute to traffic delays and require vigilance to ensure the safety of both drivers and workers.

MnDOT and the Minnesota Local Road Research Board (LRRB) are doing their best to make  work zones more efficient and safer for crew members and the traveling public alike.

Here’s a roundup of some of the great work zone safety projects under way or recently completed:

New – Temporary Traffic Control for Low Volume Roads

FlyerPicCity and county workers sometimes have trouble determining how to select the appropriate work zone for low traffic roads. The Minnesota Local Road Research Board (LRRB) recently published two supplemental guidebooks to help local agencies identify the appropriate work zone layout for low-volume urban and rural roadways based on the maintenance activity. The guides are intended to supplement MnDOT’s 2014 Temporary Traffic Control Zone Layouts Field Manual.The LRRB has also requested changes to the field manual  for low-volume roadways in a letter to the MN Committee on Uniform Traffic Control Devices.

Smart Work Zone Speed Notification 

MnDOT is testing a system on I-94 this summer that it hopes will reduce work zone crashes by raising driver awareness of upcoming congestion. Systems with the same purpose have been tested in rural work zones, but mostly applied to locations where backups were predictable.

The Smart Work Zone Speed Notification System will take a different approach, informing drivers of the speed ahead, as opposed to a variable speed limit system tested previously on I-94, which also detected congestion but provided advisory speeds to drivers. It is envisioned that the new system will have greater success in reducing rear-end crashes on large, urban freeway work zones.

The new system is being tested and evaluated on I-94, east of downtown St. Paul, during work to replace and repair the roadway.

NEW –  Speed Cameras in Work Zones

OLYMPUS DIGITAL CAMERAPolice enforcement and speed limits are the main method of reducing the speed of drivers in Minnesota work zones. While this practice is effective, reducing speeds by approximately 10 to 15 mph, it is not practical to staff every work zone with law enforcement. As an alternative, some states are using automated speed enforcement cameras in work zones.

Automated speed enforcement cameras have been shown to reduce speeds in work zones, but such research did not evaluate how the cameras impact driver attention.

This study explored driver awareness and found that automated speed enforcement cameras in work zones are not a source of driver distraction. It also revealed differences in work zone driving behavior: Older drivers were least able to follow another vehicle closely, while younger drivers were least likely to monitor their speed carefully.

NEW –  Reducing Work Zone Delay by Improving Traffic Models

2016-12 ImageAccurate estimation of delays caused by lane closures on highways is critical important to effectively manage traffic flows around work zones.

A recent study, completed in March 2016, improves methods for estimating reduced traffic capacity and diversion rates for highway work zones.

Researchers analyzed traffic patterns from past work zones in the Twin Cities metro area and were able to develop a tool that can estimate estimate traffic diversion for a given work zone.

The next step is an implementation project to test and streamline the software.

Work Zone Intrusion Reporting

TRS1506 ImageWork zone intrusions — when traveling vehicles enter the work space of a work zone — are a clear safety concern even if they do not result in an accident, and they may indicate locations where future accidents are likely.

MnDOT was interested in learning how other state DOTs collect work zone intrusion data, both the technology used for data collection and the specific information they collect.

This Transportation Research Synthesis (TRS), completed in June 2015, surveyed state DOTs and conducted follow-up interviews with states that collect work zone intrusion data. The survey found that the relatively small number of states that do collect intrusion data typically do so via paper or electronic form.

As a result of the TRS, a recently funded research project proposes to develop a simple method to track and gather information on work zone intrusions. The aim of this process will be to produce a reporting interface (in the same vein as the Crash Report Usability And Design Project for the Department of Public Safety) that gathers essential information without being onerous to work crews.

Auto Flaggers: Keeping Crews Safe, Saving Manpower

Training was provided to introduce MnDOT maintenance workers to Automatic Flagger Assistance devices, which can improve safety in work zones by allowing flaggers to provide traffic guidance without having to be in the flow of traffic.

Using a remote control, a single worker can easily operate two AFADs simultaneously, freeing up personnel to perform other tasks and speed up the completion of a road project, the pilot study found. MnDOT estimates that the resulting cost savings can cover an AFAD’s purchase costs within two years.

MnDOT has planned a project to determine whether it is feasible to use a self-propelled device to push or pull an AFAD so it can be used in moving operations such as patching potholes or cracks, which make up more than half of MnDOT’s flagging operations.

Using Smartphone and Bluetooth Technologies to Help the Visually Impaired Navigate Work Zones 

2014-12 ImageIn a study released in February 2014, researchers developed and tested a new system to provide audible messages to visually impaired pedestrians for navigating work zones.

The system uses Bluetooth beacons attached to work zone infrastructure that sends messages to a pedestrian’s smartphone app rather than the traditional method of beeping buttons that announce a message when pressed.

Technology to Alert Drivers to Work Zones

2012-26 ImageBy creating a tactile vibration and sound, rumble strips effectively alert distracted drivers to potential danger. However, they are not suitable for moving operations because repositioning them is too labor-intensive. MnDOT needed a method of alerting drivers about upcoming work zones that is more dynamic than
static signs but is portable and can be used in a moving work zone.

The Intelligent Drum Line system, developed in a 2012, could significantly improve work zone safety by relaying audible and visual warnings from traffic drums to speeding drivers as they approach. Further development is needed to ensure the system is cost-effective and portable to serve MnDOT’s needs.