Darkness in Box Culverts Not a Likely Barrier to Topeka Shiner

June 19, 2018 mndotresearch Leave a comment

Darkness box culverts does not present a complete barrier for southwestern Minnesota fish species, according to a new MnDOT study. The findings will reduce the cost and delay of future box culvert replacement projects.

“This research will allow MnDOT to save both time and money when replacing other box culverts in southwestern Minnesota by eliminating the need for a fish passage study for each one,” said Scott Morgan, Principal Hydraulics Engineer, MnDOT District 7.

The research project is one of several undertaken by MnDOT and the Local Road Research Board to better understand fish passage (more at mndot.gov/research), and ultimately develop a Minnesota culvert design manual for accommodating aquatic species.

What Was Our Goal?

In this study, researchers developed several objectives in their efforts to assess the effect of low light levels on fish passage through replacement box culverts. As part of this effort, they wanted to determine typical light levels in the replacement culvert and other box culverts in the region. They also sought to determine if the Topeka shiner and other fish move through culverts in the same numbers they pass through control areas in the same stream, and whether light levels affect frequency of movement. Finally, if a barrier is determined, researchers sought to design or recommend a method for mitigating light in the culvert.

What Did We Do?

In the field, researchers characterized light in long box culverts (at least 8 feet by 8 feet) by collecting many light levels with a light meter at the water surface within the three culverts and at control reaches. They also measured light levels within the water column to characterize the light conditions a fish would experience.

To determine whether Topeka shiners passed through culverts in similar numbers as through control reaches of the same stream, and whether light levels affected their passage, researchers employed a mark-and-recapture process. They caught fish upstream and downstream from the culverts or control reaches, marked them with an identifier indicating where they were caught and released, and then resampled to see where fish moved. They also noted other culvert features that could affect passage, such as water depth and velocity.

Image of fish tank. — In light manipulation experiments at the St. Anthony Falls Laboratory, Topeka shiners and fathead minnows were allowed to choose channels to swim along. The degree of shade in one channel was adjusted from light to deep shade.

To control for confounding variables that could affect fish movement, a laboratory study measured Topeka shiner preference for light or dark channels. Researchers used a 25-foot-long double channel box with water diverted from the Mississippi River. Fish could choose to swim along light or shaded lanes as they preferred in this light manipulation experiment.

What Did We Learn?

Although there has been increasing concern over the potential for culverts to create behavioral barriers for fish and other organisms, this was the first study that quantified these behavioral effects for fish passage. Light levels in large box culverts were not identified as a potential barrier to the fish communities present in southwestern Minnesota. Two out of the three culverts monitored showed reduced fish passage compared to the control reaches; however, fish—including Topeka shiners—were able to pass through all three.

The longest and darkest culvert had the greatest difference in movement between the culvert and the control, but this variation could not be attributed solely to light levels. This finding was supported by experiments at the St. Anthony Falls Laboratory, where fish that could select either a shaded or lighted channel showed no avoidance of the shaded channel regardless of the shading level.

The light measurements in three culverts yielded an extensive data set that can be used to model light levels through culvert barrels. Light levels at the water surface depended on the culvert entrance, dimensions, construction material, orientation and elbows, while light levels in the water column were also affected by turbidity.

What’s Next?

The conclusions of this study apply only to Topeka shiners and other small warm water fish species, and to large box culverts like those studied. Additional research is required to investigate possible barriers created by smaller, darker culverts to light-sensitive fish species and the interactions between light and other variables such as velocity.

This post pertains to Report 2017-44, “Culvert Length and Interior Lighting Impacts to Topeka Shiner Passage,” published November 2017. The full report can be accessed at mndot.gov/research/reports/2017/201744.pdf.

Traffic and Safety

MnDOT installs safety countermeasures at stop signs, stop lights

June 15, 2018 mndotresearch 1 Comment

MnDOT is working on ways to reduce crashes at intersections by making stop signs and stop lights more visible to motorists. The agency will apply reflective red metal strips on nearly 1,000 stop sign posts and fluorescent yellow tape around 100 traffic signal lights across the state this summer.

“We think these two low-cost safety countermeasures will help reduce crashes at these higher risk intersections,” said Derek Leuer, traffic safety engineer.

13-JuneSafetyMeasures_400 — Derek Leuer, traffic safety engineer, displays what the yellow reflective tape looks like around the back plate of a traffic signal light. This tape will be installed on 101 signals statewide this summer. *Photo by Sue Roe*

The stop sign project will be implemented on locally owned roads that intersect with two-lane, two-way state highways. The highways chosen are considered moderate- and high-risk crash corridors.

The reflective red strips will be installed on the stop sign post directly beneath the stop sign.

Rural intersection crashes are a serious issue in Minnesota, according to Leuer. From 2008 to 2012, there were 533 serious and fatal injury crashes at rural state highway intersections.

“This project aims to reduce those fatal and serious injury crashes in the state by making the stop signs easier to see,” he said. “Fatal right-angle crashes often are the result of one or more drivers failing to comply with a stop sign.”

The traffic signal project includes installing fluorescent yellow tape around the rectangular back plate that contains the green, red and yellow traffic signal bulbs. Leuer said this is a proven Federal Highway Administration safety countermeasure already used by other states.

“The reflective tape will make the signals look bigger and help motorists be more aware of them,” Leuer said. “This will be especially helpful at night and in low-visibility conditions.”

The florescent yellow tape will go on signals at intersections that are considered higher risk for crashes and may have a record of past crashes.

Cost of both projects is about $500,000.

MnDOT will evaluate both projects for effectiveness on an ongoing basis over the next three years.

“The installation of red reflective strips to stop sign posts and yellow fluorescent tape around signal lights may become another low-cost tool to help MnDOT improve roadway safety and move Minnesota toward zero deaths,” Leuer said.

This article by Sue Roe originally appeared in the June 13, 2018 MnDOT Newsline.

Research, Traffic and Safety

Smartphone prototype app warns drivers of high-risk curves

May 23, 2018 Christine Anderson Leave a comment

Lane-departure crashes on curves make up a significant portion of fatal crashes on rural Minnesota roads. To improve safety, solutions are needed to help drivers identify upcoming curves and inform them of a safe speed for navigating the curve.

“Traditionally there are two ways to do this: with either static signage or with dynamic warning signs,” says Brian Davis, a research fellow in the U of M’s Department of Mechanical Engineering. “However, while signing curves can help, static signage is often disregarded by drivers, and it is not required for roads with low average daily traffic. Dynamic speed signs are very costly, which can be difficult to justify, especially for rural roads with low traffic volumes.”

In a recent project led by Davis on behalf of MnDOT and the Minnesota Local Road Research Board, researchers developed a method of achieving dynamic curve warnings while avoiding costly infrastructure-based solutions. To do so, they used in-vehicle technology to display dynamic curve-speed warnings to the driver based on the driver’s real-time behavior and position relative to the curve. The system uses a smartphone app located in the vehicle to provide the driver with visual and auditory warnings when approaching a potentially hazardous curve at an unsafe speed.

“Highway curves [make up] 19 percent of the total mileage of the paved St. Louis County highway system, yet these curves account for 47 percent of all severe road departure crashes,” says Victor Lund, traffic engineer with St. Louis County. “In-vehicle warnings will be a critical strategy to reduce these crashes.”

To begin their study, researchers designed and tested prototype visual and auditory warning designs to ensure they were non-distracting and effective. This portion of the study included decisions about the best way to visually display the warnings and how and when audio messages should be used. “To create the optimal user experience, we looked at everything from how to order the audio information and when the message should play to the best length for the warning message,” says Nichole Morris, director of the U’s HumanFIRST Lab and co-investigator of the study.

Next, a controlled field test was conducted to determine whether the system helped reduce curve speeds, pinpoint the best timing for the warnings in relation to the curves, and gather user feedback about the system’s usefulness and trustworthiness. The study was conducted with 24 drivers using the test track at the Minnesota Highway Safety and Research Center in St. Cloud, Minnesota. The selected course allowed drivers to get up to highway speeds and then travel through curves of different radii, enabling researchers to learn how sensitive drivers are to the position of the warnings.

Based on the study results, the system shows both feasibility and promise. “Our in-vehicle dynamic curve warning system was well-liked and trusted by the participants,” Davis says. “We saw an 8 to 10 percent decrease in curve speed when participants were using the system.”

The project was funded by MnDOT and the Minnesota Local Road Research Board.

Policy and Planning, Research

Making social media are more effective part of public engagement plans

May 15, 2018 Christine Anderson Leave a comment

Social media can be effective as a strategic and select part of public engagement plans, according to findings of a University of Minnesota study. Co-principal investigators were Professor Ingrid Schneider of the Department of Forest Resources and Associate Professor Kathryn Quick of the Humphrey School of Public Affairs. “Public engagement for transportation planning and programs is not only required, it’s a crucial component in policy and project success,” Schneider says. “Since 2000, advances in technology and communications provide opportunities to engage with more people in new ways.”

The multipronged, multiyear project investigated current knowledge about public engagement through social media nationwide and in Minnesota. It also developed guidance about how social media may be used to reach and engage diverse populations in the state about transportation planning and projects.

For the analysis, the team used multiple methods: a literature review, telephone interviews, and four case studies. “The literature review indicated social media needs to be part of a multipronged engagement plan,” Schneider says. “While 90 percent of U.S. adults are online and 69 percent use social media, a social-media-only plan may not reach people over the age of 65 or with a high school education only. Platform use also varies considerably: African Americans and Latinos, for example, use video-sharing more than other groups.”

Phone interviews of more than 800 Minnesotans found that 72 percent use social media, and 11 to 21 percent participated in some way in planning transportation programs, policies, and projects in the previous year. In addition, 36 percent expressed interest in using social media to get information, provide feedback, or make suggestions related to transportation programs, policy, and planning.

The case studies compared pairs of transportation projects in Minnesota: two with significant social media use (Richfield, Red Wing), and two with low use (Saint Paul, Detroit Lakes). Findings revealed that the two projects with higher levels of social media had more connections with stakeholders. The quality and effectiveness of those connections, however, varied. “Government social media primarily informed audiences, while community-created pages fostered deeper engagement and dialogue,” Quick says. “In addition, the quality of social media, and their combination with other outreach technologies, influenced stakeholders’ perceptions of the engagement efforts.”

The project was funded by MnDOT and the Minnesota LRRB. “MnDOT and LRRB are committed to listening to and learning from the public,” says Renee Raduenz, MnDOT market research manager. “Social media provides a unique, efficient, and potentially inclusive tool in those efforts. This research brings us one step closer to understanding how we can maximize the power of social media to its fullest.”

Taken as a whole, the findings suggest at least four main opportunities to strengthen meaningful social media engagement:

Integrate social media into multipronged, dynamic engagement approaches. Pay attention and contribute to community-created social media pages, and provide a regular diet of new information and updates.
Consider the demographic qualities of the key stakeholders to determine how social media can be most useful.
Employ best practices for social media management, such as using hashtags to organize data, posting dynamic content (project videos, live streams), and clearly stating social media guidelines.
Expand and/or develop research and evaluation plans to understand and assess future social media engagement efforts.

Policy and Planning, Traffic and Safety

Enhanced WIM Reporting Software to Improve Commercial Traffic Weight Monitoring and Data Sharing

April 2, 2018 mndotresearch Leave a comment

An update to BullConverter allows MnDOT’s statewide weigh-in-motion (WIM) system to adopt systems from more manufacturers. The BullReporter upgrade adds new reporting functions, including a View Vehicles function that provides an image of a vehicle along with a graphical representation of WIM data, such as weight and speed.

This upgrade, developed through a research study, expands the commercial traffic information that the Office of Traffic System Management can provide to the MnDOT Office of Bridges and Structures, local and state permitting agencies, the Minnesota State Patrol and other Minnesota authorities.

“With BullReporter, now we can produce daily, weekly and monthly reports of the overweight vehicles that cross over WIM sensors,” Benjamin Timerson, Transportation Data and Analysis Program Manager, MnDOT Office of Transportation System Management.

What Was the Need?

Weigh-in-motion (WIM) systems measure characteristics of individual vehicles on the road, generating records of data that include vehicle type, speed, axle weights and spacing. When a vehicle crosses WIM sensors in the pavement, it triggers electrical signals that are transmitted to a WIM controller, which converts the signals into usable WIM vehicle data. A number of manufacturers produce WIM sensors and controllers, and each vendor employs its own methods of processing signals and producing proprietary WIM data.

Image of WIM Controller — Load sensors and loop detectors in each lane of traffic are connected to a WIM controller in a cabinet that also houses a communication device. A centralized server connects to each field WIM controller and downloads daily WIM data files, which are then processed through BullConverter/ BullReporter.

In 2009, MnDOT began using BullConverter/BullReporter (BC/BR) software with heterogeneous WIM systems. BC converts incompatible, proprietary data into a uniform comma-separated values (CSV) format. BR generates reports from the converted CSV data, allowing the analysis of WIM data over different systems.

Currently, MnDOT’s Office of Transportation System Management (OTSM) uses WIM systems from International Road Dynamics (IRD), but recently began evaluating systems from Kistler and Intercomp. In a current study, investigators are evaluating the use of Intercomp WIM controllers with Intercomp sensors, IRD controllers with Kistler sensors, and Kistler controllers with Kistler sensors. These new WIM system combinations require new conversion functions in BC.