Tag Archives: safety

Reducing speeds to improve safety for work-zone flaggers

When drivers approach a roadway work zone at high speeds, they put the lives of work-zone flaggers at risk. To keep flaggers safe on the job, U of M researchers are looking for better ways to capture drivers’ attention—and compel them to slow down—as they approach flagger-controlled work zones.

Kathleen Harder, director of the Center for Design in Health, and John Hourdos, director of the Minnesota Traffic Observatory, identified and tested new work-zone warning elements to more effectively capture and sustain driver attention. The project was funded by MnDOT and the Minnesota Local Road Research Board.

The project began with a simulator study in which participants completed three drives, each featuring a work zone with different warning treatments. One condition was a traditional four-sign configuration currently used to warn drivers approaching work zones. The other two conditions featured a variety of new elements, including signage with new messaging such as  a “one-lane road ahead” sign with flashing LED lights, a dynamic speed warning sign equipped with a loud warning horn that sounded if drivers exceeded the speed limit, and portable rumble strips.

“Overall, we found that the new set of elements is more effective than the elements currently used to reduce driving speeds on the approach to a flagger-controlled work zone,” Harder says.

Although adding LED lights to the one-lane road sign had no significant effect on drivers’ speeds, findings indicated that the dynamic speed sign coupled with the horn was more effective than the dynamic sign alone.

To test these new elements under real-world conditions, the researchers conducted field tests evaluating two configurations in Minnesota work zones. The first configuration followed the minimum standards outlined in the Minnesota Manual on Uniform Traffic Control Devices. The second deployed signs employing new messaging and attention-getting devices, including a dynamic speed warning sign, horn, and rumble strips.

Findings showed that the combination of the dynamic speed warning sign and the horn successfully reduced the overall speed of vehicles approaching the work zone. The portable rumble strips did not cause any significant speed reduction, but this may have been related to their location downstream from the dynamic speed sign and horn.

“Our findings reveal that the new set of elements designed to capture driver attention—including new messaging, a dynamic speed trailer, and horn—had a significant influence on reducing driver speed,” Harder says. “The experimental layout practically eliminated high-speed outliers and successfully reduced the approach speed to the flag operator.”

New work-zone warning app featured on KARE 11

A new app that sends warning messages to drivers as they approach work zones was featured on KARE 11 News on Thursday. The app was developed by U of M researchers in a project sponsored by MnDOT.

The story aired as part of KARE 11’s #eyesUP campaign to end distracted driving.

The app works by pairing with Bluetooth low-energy tags placed in work zones, triggering audio warnings in smartphones that are within their range. This allows drivers to get a warning message without having to look down at their phones—or at warning devices such as changeable message signs outside their vehicles. And if a driver is being distracted by their phone, the app will interrupt whatever they are doing to provide a warning that a work zone is up ahead.

U of M researchers Chen-Fu Liao and Nichole Morris, who worked on the project, are interviewed in the story, along with Ken Johnson, work-zone, pavement marking, and traffic devices engineer at MnDOT.

New video: Finding solutions to save lives

See how researchers at the Roadway Safety Institute (RSI), led by the University of Minnesota, are working to reduce crashes and save lives on our nation’s roadways in a new video.

The video features RSI director Max Donath and researchers from across the region who are working on a breadth of projects, ranging from reducing crashes at rail grade crossings to improving road safety on tribal lands. The video also highlights a few of RSI’s education efforts, including a museum exhibit designed to introduce preteens to safety concepts.

RSI was established as the Region 5 University Transportation Center in 2013 and is housed at CTS. MnDOT is a key partner for RSI, funding a variety of safety-focused projects by RSI researchers.

For more information about RSI, visit the Institute’s website.

Video Demonstration: Robotic Message Painter Prototype

In the above video, University of Minnesota-Duluth Associate Professor Ryan Rosandich tests a prototype of a robotic arm he developed to paint messages and markings on roadways. He calls the machine “The MnDOT Robot.”

During a test run in October 2015, the MnDOT robot painted a right-turn arrow and the word “ahead” on pavement at MnDOT’s Pike Lake station in Duluth.

Rosandich hopes commercial companies will show an interest in further developing his proof-of-concept technology into something that road authorities can use regularly to make work easier, faster and safer for their employees.

Companies interested in commercializing this technology can contact Andrew Morrow at amorrow@umn.edu.

Editor’s Note: The paint used in the above demonstration was diluted due to the cold weather at the time of the demonstration and does not reflect the condition of the paint expected in a typical application.

Roadway deaths and what Minnesota is doing about it

Joint article produced with MnDOT Research Services

Minnesota developed the Strategic Highway Safety Plan a decade ago, as the nation set a goal of reducing roadway deaths to less than one person per 100 million vehicle miles traveled. Last year, the nation still hadn’t reached this milestone (1.1 deaths occurred per 100 million miles), but Minnesota had lowered its fatality rate to 0.63 deaths (down from 1.48 deaths from 20 years ago).

“When I look at what Minnesota has done over the last 15 years compared to other states, we’re one of the few states that has a pretty consistent downward trend [in fatal crashes],” said Brad Estochen, MnDOT state traffic engineer, who gave an update on the highway safety plan during a recent presentation at the Roadway Safety Institute. “I think we’re doing some unique things here that have given us these results.”

These steps, Estochen says, have included passing a primary offense seatbelt law (seatbelt usage is now above 90 percent), investing in strategic safety infrastructure like high-tension cable median barriers and focused enforcement of DWI, speed and seatbelt laws.

Developing a plan

To best understand the risk factors for fatal and serious injury crashes, the state combined real-life crash data with input from professionals in engineering, law enforcement, emergency medical services, as well as everyday road users. The results showed that most crashes in the state involve multiple factors—such as road conditions, driver impairment and driver age.

Estochen said this approach of analyzing data and gaining stakeholder perspectives provided new insights into the dynamic causes of fatal and serious injury crashes.

In conjunction with the Departments of Health and Public Safety, MnDOT created a highway safety plan aimed at both professional stakeholders and the community that identified critical strategies for reducing serious traffic incidents. It has been updated in 2007 and 2014, most recently.

MnDOT also created a complimentary document for every county and MnDOT district (respectively called the county safety plan and district safety plan) to help local agencies identify locations and potential projects for reducing fatalities.

“We were the first state to take the SHSP concept to the local level. It was identified as a noteworthy practice by FHWA and other states are now starting to engage locals in developing specific plans for their use and implementation,” Estochen said.

The highway safety plan is an integral part of Toward Zero Deaths, the state’s cornerstone traffic safety program that has a goal of reducing fatalities to less than 300 per year by 2020.

Overall, Estochen said one of the best ways to reduce crashes in the state is to promote a culture of traffic safety — something he hopes the highway safety plan contributes to.

“Creating a traffic safety culture has nothing to do with building bigger and better roads,” he said. “It really has to do with making us as a state, as a community and as individuals responsible for our actions.”

MnDOT Tests Crowdsourcing to Improve Road Condition Reporting

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.

511 Citizen Reporting
Iowa launched Citizen Reporting in November. Here is an example of a citizen report.

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.”

Growing Service

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 states

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.

Winter seminars highlight research on work-zone safety, culvert design, and more

Join us in person on the U of M campus or tune in online to the CTS winter research seminars. The seminars will highlight a sampling of the latest transportation research at the U of M.

Here’s this year’s seminar schedule:

Each seminar will be held in Room 50B at the Humphrey School of Public Affairs. Or, if you can’t make it in person, you can watch the seminars live online or view recordings posted after the events. For details about the live broadcasts, see the individual seminar web pages.

There’s no cost to attend, and each seminar qualifies for one Professional Development Hour.

Hope to see you there!

New permitted left-turn model helps improve intersection safety

In recent years, the transportation community has introduced significant changes to improve left-turn safety at signalized intersections—and for good reason. Nationally, intersection crashes represent one-fifth of all fatal crashes, and most of these are crashes involving left turns.

In response to this serious safety problem, the FHWA has adopted a new national standard for permissive left turns: the flashing yellow arrow. This signal warns drivers that they should proceed with a left turn only after yielding to any oncoming traffic or pedestrians. Flashing yellow arrow signals can help prevent crashes, move more traffic through an intersection, and provide additional traffic management flexibility.

Many transportation agencies, including MnDOT, are interested in using the new flashing yellow arrow signals to accommodate within-day changes: protected left turns (signaled by a green arrow) could be used when needed to lower crash risk, while permitted left turns (signaled by a flashing yellow arrow) could be used to reduce delay when crash risk is low.

“Of course, this requires being able to predict how the risk of left-turn crashes changes as intersection and traffic characteristics change within the course of a day,” says Gary Davis, a professor of civil, environmental, and geo- engineering at the University of Minnesota.

To help engineers make more informed decisions about when to use flashing yellow arrows, Davis is leading the development of a model that could help predict the probability of left-turn crash risk at a given intersection at different times of day. This model—which will ultimately be available as a set of spreadsheet tools—will help traffic engineers determine when the crash risk is sufficiently low to allow for the safe use of flashing yellow arrows. The project is sponsored by MnDOT and the Minnesota Local Road Research Board.

To develop the statistical model, the researchers needed to determine how the risk for left-turn crashes varies depending on time of day, traffic flow conditions, and intersection features (such as number of opposing lanes, number of left-turn lanes, and median size). The process included developing a database containing left-turn crash information, intersection features, and traffic volumes, as well as developing a set of 24-hour traffic pattern estimates to help fill gaps where hourly traffic volume counts were not available. The resulting statistical model uses this information to determine relative crash risk for every hour of the day at a given type of intersection.

Currently, Davis and his team are using the model to develop a spreadsheet tool that will allow traffic engineers to choose their type of intersection and enter the available turning movement count. The tool will then generate a specialized graph for that intersection showing the relative crash risk by time of day. Any time the crash risk is at or below the level identified as acceptable, engineers can consider using flashing yellow arrows.

“By simulating how crash risk changes as traffic conditions change, this model could help identify conditions when permitted left-turn treatments would be a good choice and what times of day a protected left turn might be a better option,” Davis says.

Moving forward, Davis is leading an additional project related to the use of flashing yellow arrows, funded by the Roadway Safety Institute. The project will first review video data of drivers making permitted left turns to characterize left-turn gap acceptance and turning trajectories. Then, Davis will incorporate the findings into the existing statistical model. To further improve the model’s accuracy, the study will compare the crashes described by the simulation model with reconstructed real-world left-turn crashes.

Snow Control Tools Webinar Jan. 28

Tune in to this free webinar at noon CST on January 28 to learn about the Blowing Snow Control Cost-Benefit Web Tool. This online tool allows transportation agencies to calculate the amount they can pay private landowners (farmers) to establish a living snow fence (shrubs) or to leave standing corn rows or other structures like hay bales or silage bags to reduce blowing snow on sensitive highways.

The tool also analyzes grading and structural snow fence benefits. Reducing blowing snow on highways decreases highway maintenance costs and improves traffic safety in winter driving conditions.

To watch, register online by January 23. For more information, please visit the event web page.

Teen Driver Support System helps reduce risky driving behavior

Although teen drivers make up a small percentage of the U.S. driving population, they are at an especially high risk of being involved in a crash. In fact, drivers between ages 16 and 19 have higher average annual crash rates than any other age group.

To help teen drivers stay safe on the road, researchers at the U of M’s HumanFIRST Laboratory have been working for nearly 10 years on the development of the Teen Driver Support System (TDSS). The smartphone-based application provides real-time, in-vehicle feedback to teens about their risky behaviors—and reports those behaviors to parents via text message if teens don’t heed the system’s warnings.

TDSS provides alerts about speed limits, upcoming curves, stop sign violations, excessive maneuvers, and seat belt use. It also prevents teens from using their phones to text or call (except 911) while driving.

The research team recently completed a 12-month field operational test of the system with funding from MnDOT. The test involved 300 newly licensed teens from 18 communities in Minnesota.

To measure the effectiveness of the TDSS on driving behavior, the teens were divided into three groups: a control group in which driving behavior was monitored but no feedback was given, a group in which the TDSS provided only in-vehicle feedback to teens, and a group with both in-vehicle and parent feedback from the TDSS.

Preliminary results show that teens in the TDSS groups engaged in less risky behavior, especially the group that included parent feedback. These teens were less likely to speed or to engage in aggressive driving.

Although these results demonstrate that the TDSS can be effective in reducing risky driving behavior in teens, Janet Creaser, HumanFIRST research fellow and a lead researcher on the project, stresses that technology is not a substitute for parent interaction.

“The whole goal of our system is to get parents talking to their teens about safe driving.” Creaser says. “And maybe, if you’re a parent getting 10 text messages a week, you’ll take your teen out and help them learn how to drive a little more safely.”

Read the full article in the November issue of Catalyst.